TW202237784A - Film for forming protective film, sheet for forming protective film, composite sheet for forming protective film, and method for manufacturing device capable of suppressing peeling between a protective film and a chip caused by flux cleaning - Google Patents

Abstract

The present invention provides a protective film forming film which suppresses peeling between the protective film and a chip caused by flux cleaning, a protective film forming sheet and a protective film forming composite sheet having the protective film forming film, and a method for manufacturing a device, such as a semiconductor device. A protective film forming film is a protective film forming film used for forming a protective film, wherein a shear strength at an interface between the protective film and a silicon chip after immersion in a 2-aminoethanol is 33 N/5mm or more.

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 protective film forming sheet and a protective film forming composite sheet provided with the protective film forming film, and methods for manufacturing devices such as semiconductor wafers.

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 circuit surface side of the semiconductor wafer is turned over (face down) and bonded to the chip mounting surface. department. Therefore, a structure is formed in which the back side of the semiconductor wafer on which no circuit is formed is exposed.

Therefore, in order to protect the semiconductor wafer from shocks during transportation or the like, a hard protective film made of an organic material is often formed on the back side of the semiconductor wafer. In order to form such a protective film, an uncured resin film (hereinafter referred to as "protective film forming film") as its precursor is used. The protective film forming film is attached to the back surface of the semiconductor wafer, and is diced together with the wafer to perform singulation. A wafer having a protective film on the back surface (a wafer with a protective film) can be obtained by curing the protective film-forming film.

Moreover, in order to identify a semiconductor wafer, a mark, a letter, etc. are marked on the surface of the protective film forming film by laser marking, for example. Patent Document 1 describes a protective film-forming film comprising a resin layer α bonded to a semiconductor wafer and a resin layer β printed with a laser, and the gloss value of the surface of the resin layer β after curing is equal to or greater than a specified value. . It is described that the visibility of laser printing can be improved and the reliability can be improved by forming a film of this protective film. prior art literature patent documents

Patent Document 1: International Publication No. 2014/148496

The technical problem to be solved in the present invention

When mounting a chip with a protective film on a substrate by flip-chip, the chip with a protective film and the substrate are electrically bonded and mechanically bonded, for example, through heating steps such as reflow processing. In order to perform this bonding satisfactorily, a heating step is usually performed after coating flux (flux) on at least a part of the electrode portion of the wafer with a protective film and the electrode portion of the substrate.

Flux contains resins, solvents, activators, viscosity modifiers, etc. During the reflow process, most of the flux will volatilize when the electrode portion of the wafer with the protective film and the electrode portion of the substrate are fused and bonded. However, after the reflow process, flux residues may be generated on the substrate on which the wafer with the protective film is mounted.

Since such flux residues can cause conduction failure, corrosion, poor appearance, etc., they are usually removed by cleaning the flux. The cleaning agent (flux remover) used to remove flux contains a solvent for removing flux residues.

The inventors of the present application have found that when cleaning the flux, if the solvent contained in the cleaning agent for cleaning the flux penetrates into the interface between the protective film and the wafer, the protective film will not be protected in the reliability test of the mounting substrate. Delamination between the film and the wafer can become significant.

The present invention was made in view of such findings, and an object of the present invention is to provide a protective film forming film that suppresses peeling between the protective film and the wafer due to cleaning flux, and a protective film forming sheet including the protective film forming film. and a method for manufacturing devices such as a composite sheet for forming a protective film and a semiconductor device. Technical means to solve technical problems

The scheme of the present invention is as follows. [1] A protective film forming film, which is a protective film forming film for forming a protective film, wherein, The shear strength of the interface between the protective film and the silicon wafer dipped in 2-aminoethanol is above 33N/5mm. [2] The protective film-forming film according to [1], wherein the contact angle of 2-aminoethanol on the surface of the protective film is less than 55∘. [3] The protective film-forming film according to [1] or [2], wherein the gloss value of the surface of the protective film after immersion in 2-aminoethanol is higher than that of the surface of the protective film before immersion in 2-aminoethanol The ratio of the gloss value is 40% or more and less than 130%. [4] The protective film-forming film according to any one of [1] to [3], wherein the Young's modulus of the protective film after immersion in 2-aminoethanol is less than 1000 MPa. [5] The protective film-forming film according to any one of [1] to [4], wherein the protective film after immersion in 2-aminoethanol has an elongation at break of 15% or more. [6] A sheet for forming a protective film comprising the protective film forming film according to any one of [1] to [5] and a release film disposed on at least one main surface of the protective film forming film. [7] A composite sheet for forming a protective film, comprising the protective film forming film according to any one of [1] to [5], and a support sheet for supporting the protective film forming film. [8] A method of manufacturing a device, comprising: A step of attaching the protective film-forming film of the protective film-forming sheet described in [6] or the protective film-forming film of the protective film-forming composite sheet described in [7] to the back surface of the workpiece, the step of making the attached protective film forming film into a protective film, A step of singulating the workpiece having a protective film or a protective film forming film on the back surface to obtain a processed product of a plurality of workpieces having a protective film or a protective film forming film, A step of arranging the processed object of the workpiece with a protective film or a protective film forming film on the substrate by contacting it with flux, a step of heating the substrate and the workpiece of the workpiece with the protective film or the protective film forming film disposed on the substrate; and, A step of cleaning the substrate on which the processed object of the workpiece with a protective film is placed with a flux cleaning agent. [9] The method of manufacturing the device according to [8], which includes a step of performing laser marking on the protective film or the protective film forming film. Invention effect

According to the present invention, it is possible to provide a protective film forming film which suppresses peeling between the protective film and workpieces such as wafers due to cleaning flux, a protective film forming sheet and a protective film forming film provided with the protective film forming film. Manufacturing methods for devices such as composite sheets and semiconductor devices.

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

The workpiece is a plate-like body formed by attaching and processing the protective film of the present embodiment. Examples of the workpiece include wafers and panels. Specifically, a semiconductor wafer and a semiconductor panel are mentioned. Examples of the workpiece to be processed include wafers obtained by singulating wafers. Specifically, a semiconductor wafer obtained by singulating a semiconductor wafer can be exemplified. At this time, the protective film is formed on the wafer and the back side of the wafer.

The "surface" of a workpiece such as a wafer refers to the surface on which circuits and protruding electrodes such as bumps are formed; the "back surface" refers to the surface on which no circuits or electrodes (such as protruding electrodes such as bumps) are formed.

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

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

"Energy rays" means ultraviolet rays, electron beams, etc., preferably ultraviolet rays.

The release film is a film that supports the protective film forming film in a peelable manner. Regarding the film, the thickness thereof is not limited, and it is also used as a concept including a sheet.

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) By attaching the protective film-forming film of this embodiment to a workpiece and forming a protective film, a protective film for protecting a workpiece or a processed product of the workpiece is formed.

"Creating a protective film" means bringing the protective film forming film into a state having sufficient properties to protect a workpiece or a processed product of the workpiece. Specifically, when the protective film-forming film of the present embodiment is curable, "forming a protective film" means making an uncured protective film-forming film into a cured product. In other words, the protective-film-forming film on which the protective film is formed is a cured product of the protective-film-forming film, and is different from the protective-film-forming film.

After laminating the workpiece on the curable protective film forming film, the protective film forming film can be cured, whereby the protective film can be firmly adhered to the workpiece, and a durable protective film can be formed.

On the other hand, when the protective film-forming film of the present embodiment does not contain a curable component and is used in an uncured state, the protective film-forming film of the present embodiment is attached to the workpiece from the moment when the protective film-forming film That is, a protective film is made. In other words, the protective film-forming film formed as a protective film is the same as the protective film-forming film.

When high protective performance is not pursued, the protective film forming film does not need to be cured, so the protective film forming film is easy to use.

In the present embodiment, the protective film-forming film is preferably curable. Therefore, the protective film is preferably a cured product. As a hardened|cured material, a thermosetting material and an energy-beam cured material can be illustrated, for example. In the present embodiment, the protective film is more preferably a thermally cured product.

Moreover, it is preferable that the protective film forming film has adhesiveness at normal temperature (23 degreeC), or develops adhesiveness by heating. Thereby, both can be bonded together when a workpiece|work is superimposed on a protective film forming film. Therefore, positioning can be ensured before hardening the protective film forming film.

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

In the present embodiment, the protective film forming film is preferably one layer (single layer). A protective film is formed into a film, and high precision can be obtained in terms of thickness, so it is easy to produce. In addition, when 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 there is a risk of peeling from the adherend due to this. When the protective film is formed in one layer, the above-mentioned 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 occur (during reflow processing or when using devices).

The thickness of the protective film-forming film is not particularly limited, but is preferably 100 μm or less, 70 μm or less, 45 μm or less, and 30 μm or less. In addition, the thickness of the protective film-forming film is preferably 5 μm or more, 10 μm or more, or 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.

Hereinafter, a protective film formed on a wafer as a workpiece to be processed will be described. Specifically, the protective film formed by making the protective film forming film of this embodiment into a protective film is demonstrated using the wafer 70 with a protective film shown in FIG.

As shown in FIG. 1, in the wafer 70 with a protective film, the protective film 1 is formed on the back side (upper side in FIG. 1) of the wafer 6a, and a convex shape is formed on the front side (lower side in FIG. 1) of the wafer 6a. Electrode 6b.

A circuit is formed on the surface side of the wafer 6a, 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 the present embodiment, the wafer 70 with a protective film is placed on the wafer mounting substrate such that the surface on which the protruding electrodes 6b are formed faces the wafer mounting substrate. At this time, flux or solder for bonding the wafer 70 with a protective film to the substrate for mounting a wafer is applied to a position corresponding to the wafer 70 with a protective film on the substrate for mounting the wafer or on the protruding electrodes. paste (solder paste). Then, the protruding electrodes 6b are electrically and mechanically bonded to the substrate by specific heat treatment (for example, reflow process), and the chip 70 with a protective film is mounted on the substrate.

Flux can be used to clean electrodes, remove the oxide film of solder, reduce the surface tension of solder, etc. Solder paste also contains flux. The flux contains, for example, a resin containing rosin or a modified rosin, a solvent, an activator for removing oxides, a viscosity modifier, and the like.

Most of the flux is volatilized by heating such as reflow process, but flux residue may be generated on the part where the flux is applied. In addition, when flux is applied, flux may be applied to an unintended portion, and flux residue may be generated on the portion. Such flux residues can cause poor adhesion of underfill, corrosion such as migration, and poor appearance, so flux cleaning is performed on the substrate on which the wafer with a protective film is mounted to remove the flux. residue.

When cleaning the flux, the entire substrate on which the wafer with a protective film is mounted is immersed in a cleaning solution, or the cleaning solution is sprayed on the entire substrate, and the wafer with a protective film is brought into contact with the cleaning solution.

When the cleaning agent comes into contact with the wafer with the protective film, components contained in the cleaning agent may infiltrate into the interface between the protective film and the wafer. As a result, in the reliability test of the mounted substrate, floating or peeling occurs at the interface between the protective film and the wafer, thereby reducing reliability. In the present embodiment, in order to suppress the floating and peeling of the interface between the protective film and the wafer due to flux cleaning, the physical properties of the protective film are controlled in the following manner. In addition, the physical characteristics of the protective film shown below are physical characteristics after making a protective film into a protective film.

(1.1 Shear strength of the interface between the protective film and the silicon wafer after dipping in 2-aminoethanol) Alcohol type cleaning agents, amine type cleaning agents, etc. are illustrated as a component contained in the cleaning agent for cleaning flux. Therefore, in this embodiment, 2-aminoethanol is selected as a component contained in the cleaning agent, and a configuration capable of suppressing penetration of 2-aminoethanol into the interface between the protective film and the wafer is shown.

In this embodiment, the shear strength of the interface between the protective film dipped in 2-aminoethanol and the silicon wafer is greater than 33 N/5mm. By making the shear strength of the interface within the above range, even if 2-aminoethanol is in contact with the wafer with the protective film, the adhesion of the interface between the protective film and the wafer can be well maintained and the 2-aminoethanol can be inhibited. Ethanol permeates into the interface between the protective film and the wafer. Therefore, the adhesion reliability of the interface of the wafer with a protective film can be improved.

The shear strength of the interface is preferably 35 N/5 mm or more, more preferably 38 N/5 mm or more. On the other hand, the upper limit of the shear strength of the interface is not particularly limited, but is preferably 60 N/5 mm or less, more preferably 50 N/5 mm or less, from the viewpoint of constituent materials and manufacturing methods.

(1.2 Contact angle of 2-aminoethanol on the surface of the protective film) In this embodiment, it is preferable that the contact angle of 2-aminoethanol on the surface of the protective film is less than 55∘. By making the contact angle within the above range, 2-aminoethanol easily wets the surface of the protective film and diffuses on the surface. As a result, the 2-aminoethanol that is in contact with the protective film is easily absorbed by the protective film, so that penetration of 2-aminoethanol into the interface between the protective film and the wafer can be suppressed.

The contact angle of 2-aminoethanol on the surface of the protective film is more preferably 52∘ or less, and still more preferably 48∘ or less. On the other hand, the lower limit of the contact angle is not particularly limited, but is preferably 30∘ or more, more preferably 40∘ or more.

The contact angle of 2-aminoethanol may be measured by a known method. The specific measurement method is described in the examples.

(1.3 Gloss change rate of the protective film surface before and after immersion in 2-aminoethanol) In the present embodiment, the rate of change in glossiness of the surface of the protective film before and after immersion in 2-aminoethanol is preferably 40% or more and less than 130%. The rate of change in glossiness is represented by the ratio of the glossiness value of the surface of the protective film after immersion in 2-aminoethanol to the glossiness value of the surface of the protective film before immersion in 2-aminoethanol.

When 2-aminoethanol comes into contact with the protective film, the surface state of the protective film changes. As a result, the gloss value indicating the gloss of the surface of the protective film also changes. However, in order to easily identify a wafer with a protective film, the surface of the protective film is sometimes marked. As this marking, laser marking can be exemplified. By performing laser marking, the surface of the protective film is cut or the volume of the protective film is increased to form convex portions.

That is, since laser marking also changes the surface state of the protective film, if the surface state of the protective film is greatly changed by immersion in 2-aminoethanol, the visibility of the marking may decrease.

Therefore, by setting the rate of change in glossiness within the above-mentioned range, it is possible to suppress changes in the surface state of the protective film caused by immersion in 2-aminoethanol, and to maintain good marking visibility.

The rate of change in glossiness is more preferably 120% or less. On the other hand, the rate of change in glossiness is more preferably 80% or more, and still more preferably 95% or more.

The gloss value of the protective film before and after dipping in 2-aminoethanol can be measured in accordance with JIS Z 8741. That is, the measurement is performed by the same method as that specified in JIS Z 8741, but the measurement conditions may be different. The specific measurement method is described in the examples.

(1.4 Young's modulus of protective film after immersion in 2-aminoethanol) In this embodiment, the Young's modulus of the protective film after dipping in 2-aminoethanol is preferably less than 1000 MPa. It is considered that the protective film becomes soft while maintaining the adhesiveness with the wafer by setting the Young's modulus within the above range. That is, it is considered that even if 2-aminoethanol is in contact with a wafer with a protective film, the protective film absorbs 2-aminoethanol before 2-aminoethanol penetrates into the interface between the protective film and the wafer, thereby causing the properties of the protective film to develop. change and become soft. Furthermore, since the properties of the protective film change and become soft, in a reliability test accompanied by a sudden temperature change, the stress applied to the interface between the protective film and the wafer due to the sudden temperature change can be reduced, thereby Lifting or peeling of the interface can be further suppressed.

The Young's modulus of the protective film after immersion in 2-aminoethanol is more preferably 900 MPa or less, still more preferably 800 MPa or less. On the other hand, the lower limit of the Young's modulus of the protective film dipped in 2-aminoethanol is not particularly limited, but is preferably 300 MPa or more, more preferably 500 MPa or more, from the viewpoint of functioning the protective film.

The Young's modulus of the protective film after immersion in 2-aminoethanol can be measured based on JISK7127. That is, the measurement is performed by the same method as that specified in JIS K 7127, but the measurement conditions may be different. The specific measurement method is described in the examples.

(1.5 Elongation at break of protective film after dipping in 2-aminoethanol) In the present embodiment, the elongation at break of the protective film dipped in 2-aminoethanol is preferably 15% or more. It is considered that the protective film becomes soft while maintaining the adhesiveness with the wafer by setting the elongation at break within the above range, as in the case of Young's modulus. That is, it is considered that even if 2-aminoethanol is in contact with a wafer with a protective film, the protective film absorbs 2-aminoethanol before 2-aminoethanol penetrates into the interface between the protective film and the wafer, so that the properties of the protective film change And become soft. Furthermore, since the properties of the protective film change and become soft, in a reliability test accompanied by a sudden temperature change, the stress applied to the interface between the protective film and the wafer due to the sudden temperature change can be reduced, thereby Lifting or peeling of the interface can be further suppressed.

The elongation at break of the protective film after immersion in 2-aminoethanol is more preferably 17% or more, and still more preferably 19% or more. On the other hand, the upper limit of the elongation at break of the protective film after immersion in 2-aminoethanol is not particularly limited, but from the viewpoint of performing the function of the protective film, it is more preferably 40% or less, more preferably 30% or less .

The elongation at break of the protective film after dipping in 2-aminoethanol may be measured simultaneously with Young's modulus in accordance with JIS K 7127. The specific measurement method is described in the examples.

(1.6 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) preferably contains at least a polymer component (A), a curable component (B), a filler (E) and a coupling agent. (F) The resin composition. The polymer component can be regarded as a component formed by the polymerization reaction of a polymerizable 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 considered that the composition for forming a protective film contains both a polymer component and a curable component. By.

(1.6.1 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, particularly preferably 200,000 to 1 million. As such a polymer component, for example, acrylic resins, urethane resins, phenoxy resins, silicone resins, saturated polyester resins, etc. can be used, and acrylic resins are particularly preferably used.

In addition, in this specification, unless otherwise indicated, a "weight average molecular weight" means the polystyrene conversion value measured by the gel permeation chromatography (GPC) method. In the measurement based on this method, for example, high-speed chromatography columns "TSK guard column H _XL -H", "TSK Gel GMH XL ", "TSK Gel GMH _XL ", "TSK Gel G2000 H _XL "(all of the above are manufactured by TOSOH CORPORATION) is used for measurement with 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 having an alkyl group of 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 to 40°C, -35°C to 35°C, -20°C to 30°C, -10°C to 25°C, and -5°C to 20°C. By setting the lower limit of the glass transition temperature of the acrylic resin to the above value, excessive swelling and deformation of the protective film due to absorption of the flux cleaning agent is suppressed, and it becomes easier to maintain the shape of the protective film having the same shape as the chip. In addition, by setting the upper limit value of the glass transition temperature of the acrylic resin to the above value, the viscosity of the protective film-forming film is moderately improved, and the adhesive force of the protective film-forming film to the workpiece is improved, and the adhesive force of the protective film to the workpiece is improved. Moderate increase.

式中，Tg為丙烯酸樹脂的玻璃化轉變溫度；m為2以上的整數；Tg _k為單體m的均聚物的玻璃化轉變溫度；W _k為丙烯酸樹脂中的衍生自單體m的結構單元m的質量分數，其中，W _k滿足下式。 [數學式2]

式中，m及W _k與所述m及W _k相同。 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 the m types of monomers derived from the structural units in the acrylic resin are sequentially assigned any non-repeating serial number from 1 to m and named as "monomer m", it can be calculated using the Fox formula shown below The glass transition temperature (Tg) of the acrylic resin. [mathematical formula 1]

In the formula, Tg is the glass transition temperature of the acrylic resin; m is an integer above 2; Tg _k is the glass transition temperature of the homopolymer of the monomer m; W _k is the structure derived from the monomer m in the acrylic resin The mass fraction of unit m, where W _k satisfies the following formula. [mathematical formula 2]

In the formula, m and W _k are the same as the aforementioned m and W _k .

As Tg _k , a value described in a polymer data handbook, an adhesive handbook, or a polymer handbook (Polymer Handbook), etc. can be used. For example, the Tg _k of the homopolymer of methyl acrylate is 10°C, the Tg _k of the homopolymer of n-butyl acrylate is -54°C, the Tg _k of the homopolymer of methyl methacrylate is 105°C, and the Tg k of the homopolymer of acrylic acid- The Tg _k of the homopolymer of 2-hydroxyethyl ester is -15°C, the Tg _k of the homopolymer of glycidyl methacrylate is 41°C, and the Tg _k of the homopolymer of 2-ethylhexyl acrylate is -70°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 80 parts by mass, 8 to 70 parts by mass, 10 to 60 parts by mass, 12 to 55 parts by mass, 14 parts by mass, ~50 parts by mass, 15~45 parts by mass. When the content of the polymer component is within the above range, excessive swelling and deformation of the protective film due to absorption of the flux cleaning agent is suppressed, and it becomes easier to maintain the shape of the protective film having the same shape as the wafer. In addition, it is easy to control the tackiness of the protective film forming film.

(1.6.2 Thermosetting components) The curable component (B) forms a hard protective film by curing a protective film forming film. As the curable component, a thermosetting component, an energy ray-curable component, or a mixture of these components can be used. When curing is performed by irradiating energy rays, the light transmittance of the protective film-forming film according to this embodiment decreases due to the inclusion of a filler, a colorant, and the like described later. Therefore, for example, when the thickness of the protective film forming film becomes thicker, energy ray curing tends to become insufficient.

On the other hand, even if the thickness of a thermosetting protective film-forming film becomes thick, it can fully harden by heating, Therefore The protective film with high protective performance can be formed. In addition, a plurality of protective film forming films can be collectively heated and thermally cured using common heating tools such as a heating furnace.

Therefore, in the present embodiment, it is preferable that the curable component is thermosetting. That is, the protective film-forming film of the present embodiment is preferably thermosetting.

Whether or not the protective film forming film is thermosetting can be judged by the following method. 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. At this time, when the protective film forming film after heating and cooling is harder, it is judged that This protective film forming film is thermosetting.

As the thermosetting component, for example, epoxy resins, thermosetting polyimide resins, unsaturated polyester resins, and mixtures thereof are preferably used. In addition, the thermosetting polyimide resin is a generic 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 in, for example, the Journal of the Textile Society of Japan "Fiber and Industry" (Journal of the Japan Textile Society "繊维と工业"), Vol.50, No.3 (1994), P106-P118 middle.

Epoxy resin, which is a thermosetting component, has the property of forming a three-dimensional network when heated to form a strong coating. As such an epoxy resin, various well-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 to 5000 g/eq, more preferably 100 to 2000 g/eq, and still more preferably 150 to 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; Glycidyl ethers of alcohols such as diol and polypropylene glycol; glycidyl ethers of carboxylic acids such as phthalic acid, isophthalic acid, and tetrahydrophthalic acid; glycidyl substituted aniline isocyanurate, etc. Epoxy resins of the glycidyl or alkyl glycidyl type with active hydrogen bonded to nitrogen atoms; such as vinyl dioxide cyclohexene, 3,4-epoxycyclohexylmethyl-3,4 -dicyclohexanecarboxylate, 2-(3,4-epoxy)cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane-dioxane, etc., by, for example, A so-called alicyclic epoxide in which an epoxy group is introduced by oxidizing the carbon-carbon double bond in the molecule. In addition, epoxy resins having a biphenyl skeleton, a bicyclohexadiene 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 the curing agent for the 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 normal temperature (23° C.) and is activated by heating above a certain temperature to react with epoxy resin. The activation methods of thermally active latent epoxy resin curing agents include: the method of generating active substances (anions, cations) through a chemical reaction based on heating; Epoxy resins are compatible and dissolved, thereby initiating a curing reaction; a method of eluting a molecular sieve-sealed curing agent at a high temperature to initiate a curing reaction; a method of using microcapsules, etc.

Among the exemplified methods, it is preferable to stably disperse in the epoxy resin at about room temperature, and to be compatible and dissolved with the epoxy resin at high temperature to initiate a curing reaction.

Specific examples of heat-activated latent epoxy resin curing agents include various onium salts, dibasic acid dihydrazide compounds, dicyandiamide, amine adduct (amine adduct) curing agents, imidazole compounds, etc. Melting point active hydrogen compounds, etc. These thermoactive latent epoxy resin curing agents may be used alone or in combination of two or more. In this embodiment, dicyandiamine is particularly preferred.

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 novolak resins, o-cresol novolac resins, p-cresol novolak resins, tert-butylphenol novolac resins, dicyclopentadiene cresol resins, poly-p-vinylphenol resins, bisphenol Type A novolak resins or their modified products, etc.

The phenolic hydroxyl group contained in these phenolic resins is easy to add 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 0.01 to 30 parts by mass, 0.1 to 20 parts by mass, 0.2 to 15 parts by mass, or 0.3 to 10 parts by mass relative to 100 parts by mass of the epoxy resin. Since the network structure of a protective film becomes dense by making content of a hardening|curing agent (C) more than the said lower limit, it becomes easy to acquire the performance which protects a workpiece|work as a protective film. In addition, by making the content of the curing agent (C) below the above-mentioned upper limit, the protective film absorbs the flux cleaning agent moderately, so it is possible to further suppress penetration of the solvent contained in the flux cleaning agent into the protective film and the wafer. at the interface between.

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

The content of the curing accelerator is preferably 0.01 to 30 parts by mass, 0.1 to 20 parts by mass, 0.2 to 15 parts by mass, or 0.3 to 10 parts by mass relative to 100 parts by mass of the epoxy resin. Since the network structure of a protective film becomes dense by making content of a hardening accelerator (D) more than the said lower limit, it becomes easy to acquire the performance which protects a workpiece|work as a protective film. Moreover, since the protective film absorbs a flux cleaning agent moderately by making content of a hardening accelerator (D) into below the said upper limit, penetration of the solvent contained in a flux cleaning agent into a protective film and a flux cleaning agent can be suppressed further. interface between chips.

The total content of the thermosetting component and the curing agent when the total weight of the composition for forming a protective film is 100 parts by mass is preferably 3 to 80 parts by mass, 5 to 60 parts by mass, 7 to 50 parts by mass, or 9 to 40 parts by mass. parts by mass, 10 to 30 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. By adjusting the degree of curing by setting the total content of the thermosetting component and the curing agent to be equal to or less than the above-mentioned upper limit, the protective film absorbs the flux-removing agent appropriately, so that the infiltration of the solvent contained in the flux-removing agent can be further suppressed to the interface between the protective film and the wafer.

(1.6.3 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 irradiating an energy ray, 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.

(1.6.4 Filling material) By making the protective film forming film contain the filler (E), it becomes easy to adjust the thermal expansion coefficient of the protective film obtained by making the protective film forming film into a protective film, and by making the thermal expansion coefficient close to the thermal expansion coefficient of the workpiece, use The bonding reliability of the wafer with a protective film obtained by forming a 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 can be further improved.

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

As preferred inorganic fillers, for example, powders of silica, alumina, talc, calcium carbonate, red iron oxide, silicon carbide, boron nitride, etc.; beads obtained by spheroidizing these inorganic fillers; these Surface modification of inorganic filler materials; single crystal fibers of these inorganic filler materials; glass fibers, etc. Among them, silicon dioxide and surface-modified silicon dioxide are preferable.

In this embodiment, from the viewpoint of dispersibility in a coating agent described later, surface-modified silica is preferable, and the surface-modified silica is preferably modified so as to reduce reactivity with 2-aminoethanol. Sexual silica. Specifically, surface modification with a low-polarity functional group is preferable, and modification with a vinyl group is preferable. By using such surface-modified silica, it is possible to appropriately apply the cohesion between the particles of the silica filler in the protective film while maintaining its dispersibility in the coating agent. Therefore, there is a tendency that the shear strength of the interface between the protective film dipped in 2-aminoethanol and the silicon wafer is improved.

In this embodiment, it is preferred that the average particle size of the filler material is small. Specifically, the average particle diameter of the filler is preferably 0.02 to less than 1 μm, 0.05 to less than 0.5 μm, and 0.10 to less than 0.4 μm.

By setting the average particle diameter of the filler to the above value, the effect obtained by using silica surface-modified with a specific functional group can be enhanced.

In addition, in this specification, unless otherwise specified, the "average particle diameter" refers to the particle diameter (D50 ) 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 to 80 parts by mass, 30 to 75 parts by mass, 40 to 70 parts by mass, and 45 to 65 parts by mass.

By making the lower limit of content of a filler into the said value, the said effect by containing a filler can be exhibited further. Moreover, the adhesive force between a protective film forming film and a workpiece|work can be improved more by making the upper limit of content of a filler into the said value.

(1.6.5 Coupling agent) By making the protective film-forming film contain a 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 at the same time, the water resistance can be improved (moisture and heat resistance). As the coupling agent, silane coupling agent is preferred in view of its wide applicability and cost advantage.

In this embodiment, silane coupling agents having the following groups as reactive functional groups are preferred, and the groups are: alkyl groups such as methyl and ethyl; alkoxy groups such as methoxy and ethoxy; Glycidyloxy groups such as epoxy groups; amino groups; vinyl groups such as (meth)acryloxy groups; mercapto groups, etc., preferably silane coupling agents having alkyl and alkoxy groups.

In addition, as the silane coupling agent, an oligomer type silane coupling agent having a molecular weight of 300 or more is more preferable than a low molecular weight silane coupling agent having a molecular weight of less than 300. When the coupling agent is an oligomer type silane coupling agent, there exists a tendency for the chemical bond between silicon etc. and a protective film formation film to be exhibited comparatively firmly.

As a specific silane coupling agent, a silane coupling agent (oligomer type silane coupling agent) having a plurality of alkoxysilyl groups in the molecule can be used. For example, epoxy group-containing oligomer type silane coupling agents manufactured by Shin-Etsu Chemical Co., Ltd., trade names "X-41-1053", "X-41-1059A", "X- 41-1056", "X-40-2651"; mercapto-containing oligomer silane coupling agents "X-41-1818", "X-41-1810", "X-41-1805", etc. These silane coupling agents can be used alone or in combination of two or more. Moreover, there exists a tendency for the shear strength of the interface between the protective film after dipping in 2-aminoethanol and a silicon wafer to improve by using the said filler and the said silane coupling agent together.

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.

(1.6.6 Colorants) It is preferable that a protective film forming film contains a coloring agent (G). In this way, since the back surface of the workpiece such as a wafer is covered, various electromagnetic waves generated in the electronic device can be shielded, and failures of the workpiece such as a wafer can be reduced.

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

Examples of organic pigments and organic dyes include aminium dyes, cyanine dyes, merocyanine dyes, croconium dyes, squarylium dyes, Azulenium pigments, polymethine pigments, naphthoquinone pigments, pyrylium pigments, phthalocyanine pigments, naphthalocyanine pigments, naphthalactam pigments, azo Pigments, condensed azo pigments, indigo pigments, perinone pigments, perylene pigments, dioxazine pigments, quinacridone pigments, isoindolinone pigments, quinophthalone Pigments, pyrrole pigments, thioindigo pigments, metal complex pigments (metal complex salt dyes), dithiol metal complex pigments, indoxyl phenol pigments, triarylmethane pigments, anthraquinone pigments, dioxazine pigments, naphthol pigments, imine pigments, benzimidazolone pigments, pyranthrone pigments and threne pigments, etc. The organic colorant may be composed of one material or may be composed of a plurality of materials.

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, carbon black is particularly preferably used.

The blending amount of the coloring agent 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 40 μm, when the total weight of the protective film-forming composition is 100 parts by mass The content of the coloring agent 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 diameter of the coloring agent is preferably 1 to 500 nm, 3 to 100 nm, or 5 to 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.

(1.6.7 Other additives) The protective film-forming film composition may contain, as other additives, photopolymerization initiators, crosslinking agents, plasticizers, antistatic agents, antioxidants, gettering agents, Adhesives, strippers, etc.

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

The sheet 51 for forming a protective film shown in FIG. 2A has a structure in which a first release film 21 supporting the protective film forming film 10 is disposed on one principal surface 10a of the protective film forming film 10, and a first release film 21 is disposed on the other principal surface 10b. The second peeling film 22 is arranged on the structure.

On the other hand, the sheet 52 for forming a protective film shown in FIG. 2B 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 on the other side A structure in which a release film is not disposed on one main surface 10b.

The sheet for forming a protective film of this embodiment is used for attaching a protective film forming film to the workpiece when processing a workpiece, and is used on the workpiece or the processed object of the workpiece by making the protective film forming film into a protective film. form a protective film.

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 compared with the length in the short direction. In addition, it may be in the form of a sheet roll in which such a long sheet is wound.

Furthermore, the sheet|seat for protective film formation may be the sheet|seat for protective film formation which carried out die-cut processing so that it may have a specific closed shape corresponding to the protective film formation film affixed to a workpiece. The specific closed shape is not particularly limited, but is preferably approximately the same shape as the workpiece to be attached.

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

The substrate is not particularly limited as long as it is capable of supporting the protective film-forming film until the protective film-forming film is attached to the workpiece. Generally, it is made of a resin-based film (hereinafter referred to as "resin"). Membrane") composition.

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-(formaldehyde base) acrylic copolymer film, ethylene-(meth)acrylate copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film, etc. In addition, crosslinked films of these films can also be used. Furthermore, a laminated film of these films may also be used. In this 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 drying and curing the coating film. The release agent layer composition is not particularly limited as long as it is a material that can impart releasability to the base material and the protective film forming film. In this embodiment, the release agent layer composition is preferably, for example, an alkyd release agent, a silicone release agent, a fluorine release agent, an unsaturated polyester release agent, a polyolefin release agent, Among the paraffin-based release agents, silicone-based release agents are preferred.

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

In addition, when peeling films are formed on both main surfaces of the protective film forming film, it is preferable to increase the peeling force of one peeling film to make it a heavy peeling type peeling film, and to reduce the peeling force of the other peeling film so that Make it a light-peeling type release film.

(3. Composite sheet for protective film formation) The composite sheet for protective film formation of this embodiment has the above-mentioned protective film forming film and the support sheet which supports the protective film forming film. The configuration of the support sheet is not particularly limited as long as the adhesiveness and peelability of the workpiece can be controlled enough to obtain a workpiece with a protective film. For example, the support sheet may be composed only of a base material having specific rigidity described later. In this embodiment, in order to control the adhesiveness and peelability more easily, it is preferable that the supporting sheet is an adhesive sheet having a base material and an adhesive layer.

The composite sheet 61 for forming a protective film shown in FIG. 3A has a structure including: an adhesive sheet 4 in which an adhesive layer 42 is laminated on one surface of a substrate 41; The protective film forming film 10 and the adhesive layer 5 for jigs laminated on the peripheral portion of the protective film forming film 10 on the side opposite to the adhesive sheet 4 . 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. Therefore, the adhesive sheet is a supporting sheet.

Moreover, the composite sheet 62 for protective film formation shown in FIG. The protective film on the layer 42 side forms the film 10 .

The protective film-forming composite sheet of this embodiment is used to be attached to the workpiece to support the workpiece when the workpiece is processed, and to be used on the workpiece or the processed object of the workpiece by forming a protective film-forming film into a protective film. form a protective film.

Specifically, it is used to support the wafer when the wafer as the workpiece is diced, and to form a protective film on the wafer as the processed product obtained by dicing, but the present invention is not limited thereto.

(3.1 Adhesive sheet) The adhesive sheet 4 of the composite sheet for protective film formation of this embodiment is comprised by including the base material 41 and the adhesive agent layer 42 laminated|stacked on one surface of the base material 41.

(3.1.1. Substrate) The base material 41 of the adhesive sheet 4 is not particularly limited as long as it is suitable for processing workpieces, such as wafer dicing and expanding (expanding). called "resin film").

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, modified membranes such as crosslinked membranes and ionomer membranes of these membranes can also be used. The aforementioned substrate 41 may be a film composed of one of these films, or may be a laminated film obtained by further combining two or more of these films. In the present embodiment, a polypropylene film and a polybutylene terephthalate film are preferable from the viewpoint of heat resistance when used in the step of heating the composite sheet for protective film formation.

In order to improve the adhesiveness between the above-mentioned resin film and the adhesive layer 42 laminated on its surface, one or both surfaces of the above-mentioned resin film may be subjected to surface treatment such as oxidation method or roughening method, or primer coating as necessary. Treatment (primer treatment). Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet method), flame treatment, hot air treatment, ozone-ultraviolet irradiation treatment, etc.; 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 will not be specifically limited if it can function suitably in each process which uses the composite sheet for protective film formation. Preferably it is 20-200 micrometers, More preferably, it is 40-170 micrometers, Especially preferably, it is the range of 50-140 micrometers.

(3.1.2. Adhesive layer) The adhesive layer 42 included in the adhesive sheet 4 of the protective film forming composite sheet according to this embodiment may be composed of a non-energy ray-curable adhesive or an energy ray-curable adhesive. As the non-energy ray-curable adhesive, an adhesive having required adhesive force and re-peelability is preferable, for example, an acrylic adhesive, a rubber adhesive, a silicone adhesive, a urethane adhesive, Polyester adhesives, polyvinyl ether adhesives, etc. Among them, an acrylic adhesive having high adhesion to the protective film forming film 10 and capable of effectively suppressing the peeling of the workpiece or a processed product of the workpiece in a dicing step or the like is preferable. Moreover, an acrylic adhesive is also preferable from the viewpoint of being easy to control the pick-up suitability of the workpiece of the workpiece|work with a protective film.

On the other hand, since the adhesive force of the energy ray-curable adhesive is lowered by energy ray irradiation, when it is necessary to separate the workpiece or the processed product of the workpiece from the adhesive sheet 4, 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 (copolymer) polymer into which an energy ray curable group is introduced can be illustrated. Esters of polyols and (meth)acrylic acid can be exemplified as energy ray curable monomers and/or oligomers. In addition, the energy ray-curable adhesive may contain additives such as a photopolymerization initiator and a crosslinking agent in addition to the energy ray-curable component.

The thickness of the adhesive layer 42 is not specifically limited as long as it can function suitably in each process which uses the composite sheet 3 for protective film formation. Specifically, the thickness of the adhesive layer is preferably 1 to 50 μm, 2 to 30 μm, 2 to 20 μm, 3 to 10 μm, or 3 to 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. Adhesives, polyester adhesives, polyvinyl ether adhesives, etc. Among them, an acrylic adhesive that has high adhesion to a jig such as a ring frame and can effectively suppress peeling of the protective film-forming composite sheet 3 from the ring frame or the like in a cutting step or the like is preferable. In addition, a base material as a core material may be interposed in the thickness direction of the jig adhesive layer 5 .

From the viewpoint of adhesiveness to a jig such as a ring frame, the thickness of the jig adhesive layer 5 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. Apply to the peeling surface of a 1st peeling film, and if necessary, make it dry, and form a protective film forming film on a 1st peeling film. As a result, a sheet for forming a protective film as shown in FIG. 2B was obtained.

Moreover, 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. 2A was obtained.

Furthermore, you may perform punching processing to the sheet|seat for protective film formation as needed. For example, punching can be performed as follows. 4A and 4B, using a die (not shown), from the protective film forming film 10 side of the protective film forming sheet 51, 52, to penetrate the protective film forming film 10 and reach the first release film 21 cuts into the notch 14 by way of a portion of the surface. This operation of cutting into the incision so as to reach a part of the surface without cutting off completely is called a half-cut. As a result, the notch 14 is formed in a part of the surface of the sheet|seat 10 for protective film formation so that it may have a specific closed shape.

Since the protective film-forming film is divided into the protective film-forming film 16 die-cut into a specific closed shape and the useless part 17 connected therearound by forming the slit, the useless part can be removed.

(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 is possible to separately produce a first laminate including a protective film forming film and a second laminate including an adhesive sheet as a support sheet, and then use the first laminate and the second laminate to bond the protective film forming film and the adhesive sheet Manufactured by layering.

The 1st laminated body can be manufactured by the method similar to the sheet|seat for protective film formation mentioned above. 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.

In the first laminate, the protective film forming film and the second peeling film can be formed into a desired shape, such as a circle, by performing half-cutting as necessary by the same method as the protective film forming sheet described above. At this time, excess portions of the protective film-forming film and the second release film generated by the half-cut can be appropriately removed.

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") fabrics"). 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 bonded 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.

Here, 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 the adhesive layer may be cured after being laminated with the protective film forming film. . Furthermore, when the adhesive layer is cured after being laminated with the protective film forming 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, it is preferably 50 to 1000 mJ/cm ² in terms of light intensity, and particularly preferably 100 to 500 mJ/cm ² . In addition, when electron beams are used, the irradiation dose of energy rays is preferably about 10 to 1000 krad.

After obtaining the first laminated body and the second laminated body by the above method, while peeling off the second peeling film in the first laminated body, the third peeling film in the second laminated body is peeled off, and the first laminated body The exposed protective film forming film is bonded to the adhesive layer of the adhesive sheet exposed in the second laminate.

The adhesive sheet can be cut into a desired shape as required, such as a circle with a diameter larger than that of the protective film forming film. In this case, what is necessary is just to remove the excess part of the adhesive sheet produced by cutting suitably. In addition, the adhesive sheet may be made into a circular shape such that the protective film forming film and the adhesive layer have the same diameter.

Thus, an adhesive sheet in which an adhesive layer is laminated on a substrate, a protective film-forming film laminated on the adhesive layer side of the adhesive sheet, and a first adhesive sheet laminated on the side opposite to the adhesive sheet of the protective film-forming film are obtained. A composite sheet for forming a protective film made of a release film. If necessary, after peeling off a 1st release film, the adhesive layer for jigs is formed in the peripheral part of the exposed protective film forming film or adhesive layer.

(6. Manufacturing method of device) As an example of a method of manufacturing a device for forming a film using the protective film of this embodiment, a method of manufacturing a mounting substrate in which a wafer with a protective film is mounted on a substrate by It is obtained by processing the wafer on which the film for forming a protective film is attached.

The manufacturing method of the device of the present embodiment has at least the following steps 1 to 6: Step 1: a step of attaching the protective film forming film included in the protective film forming sheet or the protective film forming film included in the protective film forming composite sheet to the back surface of the wafer, Step 2: A step of making the attached protective film forming film into a protective film, Step 3: A step of singulating the wafer with a protective film or a protective film forming film on the back side to obtain a plurality of wafers with a protective film or a protective film forming film, Step 4: a step of arranging the wafer with the protective film or the protective film forming film on the substrate by contacting it with flux, Step 5: a step of heating the wafer with the protective film or the protective film-forming film disposed on the substrate and the substrate, Step 6: A step of cleaning the substrate on which the wafer with the protective film is disposed with a flux cleaning agent.

In addition, it can be seen from the above that step 2 can be performed before step 3 and 4, or after step 3 and before step 4, or after step 3 and 4, but it needs to be performed before step 6.

The manufacturing method of the device having the above steps 1 to 6 will be described with reference to FIGS. 5 to 7 .

As shown in FIG. 5A , the protective film forming film 10 of the protective film forming sheet 51 is attached to the back surface of the wafer 6 (step 1). What is necessary is just to peel off the 2nd peeling film 22 as needed.

Furthermore, as shown in FIG. 5B , the protective film forming film 10 of the protective film forming composite sheet 61 is attached to the wafer 6 (step 1). At this time, the outer peripheral portion of the protective film forming film 10 may be fixed by the ring frame 7 . In this embodiment, as shown in FIG. 3A , since the adhesive layer 5 for the jig is provided on the outer peripheral portion of the protective film forming film 10 , the adhesive layer 5 for the jig is attached to the ring frame 7 . Wafer 6 is attached to the surface of protective film forming film 10 opposite to the surface to which adhesive layer 42 is attached. When attaching the protective film-forming film 10 to the wafer 6 , the protective film-forming film 10 may be heated as necessary to exhibit adhesiveness.

Then, the attached protective film-forming film 10 is made into a protective film to form a protective film (step 2), and a wafer 6 with a protective film is obtained. When the protective film forming film 10 is thermosetting, what is necessary is just to heat the protective film forming film 10 at a specific temperature for an appropriate time. In addition, when the protective film forming film 10 is energy ray curable, it is sufficient to irradiate the energy ray from the side of the adhesive sheet 4 or the peeling film.

In addition, the curing of the protective film forming film 10 may be performed after the dicing step, or the protective film forming film may be cured after picking up the wafer with the protective film forming film from the adhesive sheet.

Next, if necessary, the wafer 6 with a protective film and the ring frame 7 obtained by forming the protective film forming film 10 of the protective film forming sheet 51 shown in FIG. 5A as a protective film are attached to a known dicing sheet 22. Then, the wafer 6 with the protective film is diced to obtain the wafer with the protective film 1 shown in FIG. 6 (the wafer 70 with the protective film) (step 3).

In addition, the wafer 6 with a protective film obtained by forming the protective film forming film 10 of the protective film forming composite sheet 61 shown in FIG. wafer (wafer with protective film 70) (step 3).

Then, the dicing sheet or the adhesive sheet is spread in the planar direction as necessary, and the wafer with the protective film is picked up from the dicing sheet by a suction collet or the like.

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

As shown in FIG. 7, the wafer with protective film 70, which has been transported to the next step, is transported to the substrate 50 using the adsorption collet C, and the wafer with protective film 70 is removed from the adsorption collet C at the terminal portion on the substrate. It is detached and arranged at a position where a connection electrode such as a bump can be connected to a terminal portion such as a connection pad (step 4). At this time, flux is applied to at least one of the connection electrode side of the wafer with a protective film and the terminal portion on the substrate by a known method.

Simultaneously, heat treatment (for example, reflow treatment) is performed on the wafer with a protective film and flux placed at a predetermined position on the substrate (step 5). Regarding the reflow processing conditions, for example, the maximum heating temperature is preferably 180 to 350° C., and the reflow time is 2 to 10 minutes.

In the reflow process, in the state where the surface tension of the solder is lowered and the surface tension of the solder is removed, the chip with a protective film The protruding electrode 6b of 70 is melted and electrically and mechanically bonded to the terminal portion on the substrate, whereby the protective film-attached chip 70 is mounted on the substrate. Most of the flux will volatilize before the reflow process is completed, but part of the flux will remain in the form of flux residue near the junction between the wafer with the protective film and the substrate.

In order to remove this flux residue, in the present embodiment, the substrate on which the wafer with a protective film is mounted is cleaned with a flux cleaning agent (step 6). Specifically, the substrate is cleaned by immersing the substrate in a flux cleaning agent or spraying the flux cleaning agent on the substrate. The flux cleaning agent is preferably an alcohol cleaning agent or an amine cleaning agent, more preferably a flux cleaning agent that is both an amine and an alcohol type, and particularly preferably a flux cleaning agent containing 2-aminoethanol.

In this embodiment, since the protective film has the above-mentioned physical properties, even if the flux is cleaned, it is possible to prevent 2-aminoethanol from penetrating into the interface between the protective film and the silicon wafer, so that the interface can be effectively suppressed in the reliability test. floating or peeling off.

In addition to the above steps 1 to 6, the manufacturing method of the device may further include a step of laser marking the protective film or the protective film forming film (step 7).

Step 7 is performed after Step 2 and before Step 5. In this embodiment, step 7 is preferably performed before step 3 and step 4.

By performing laser marking, a wafer with a protective film forming film or a wafer with a protective film can be identified after laser marking.

For laser marking, marking can be performed by cutting the surface of the protective film forming film or the protective film by irradiating laser light, or forming embossing by increasing the volume of the protective film forming film or protective film by irradiating laser light. The marking of the shape part. Laser marking may be performed using a known laser marking device.

(7. Variations) A jig adhesive layer similar to the jig adhesive layer 5 of the above-mentioned protective film forming composite sheet 61 may be additionally provided on the peripheral portion of the adhesive layer 42 of the adhesive sheet 4 of the protective film forming composite sheet 62 .

In addition, a peeling film may be laminated on the surface of the protective film forming film 10 side of the protective film forming composite sheets 61 and 62 to protect the protective film forming film until the protective film forming film is used.

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 scope 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) [The first release film (heavy release type release film)] "SP-PET502150 (thickness 50 μm)" manufactured by LINTEC Corporation was used.

[Second release film (light release type release film)] "SP-PET381130 (thickness 38 μm)" manufactured by LINTEC Corporation was used.

[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 became 50 mass %, and the coating agent was prepared. (A) Polymer composition (A-1): A (meth)acrylate copolymer obtained by copolymerizing 85 parts by mass of methyl acrylate and 15 parts by mass of 2-hydroxyethyl acrylate (weight average molecular weight: 400,000, glass transition temperature: 6°C) (A-2): 15 parts by mass of n-butyl acrylate, 62 parts by mass of methyl acrylate, 13 parts by mass of glycidyl methacrylate and 10 parts by mass of 2-hydroxyethyl acrylate copolymerized ( Meth)acrylate copolymer (weight average molecular weight: 400,000, glass transition temperature: -1°C) (B) Curable component (thermosetting component) (B-1) bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, jER828, epoxy equivalent 184~194g/eq) (B-2) Bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, jER1055, epoxy equivalent 800~900g/eq) (B-3) Dicyclopentadiene-type epoxy resin (manufactured by DAINIPPON INK AND CHEMICALS, INC., EPICLON HP-7200HH, softening point 88-98° C., epoxy equivalent 255-260 g/eq) (C) Curing agent: dicyandiamide (manufactured by Mitsubishi Chemical Corporation, DICY7) (D) Curing accelerator: 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by SHIKOKU CHEMICALS CORPORATION, CUREZOL 2PHZ-PW) (E) Filling material (E-1) Epoxy-modified spherical silica filler (Admatechs, SC2050MA, average particle size 0.5 μm) (E-2) Vinyl-modified spherical silica filler (Admatechs, SC105G-MMQ, average particle size 0.3 μm) (F) Silane coupling agent: oligomer type silane coupling agent containing epoxy, methyl and methoxy groups (manufactured by Shin-Etsu Silicone Co. Ltd., X-41-1056, epoxy equivalent 280g/ eq) (G) Colorant Organic coloring agent: phthalocyanine blue pigment (pigment Blue 15:3 fixed with 3 times the mass of styrene-acrylic resin), isoindolinone yellow pigment (3 times the mass Pigment Yellow 139 fixed with styrene-acrylic resin) and diketopyrrolopyrrole red pigment (pigment Red 264 fixed with 3 times the mass of styrene-acrylic resin) according to 38: Pigments obtained by mixing 18:44 (blue:yellow:red, mass ratio)

[Table 1] Proportion Example 1 Example 2 Comparative example 1 Comparative example 2 polymer composition A-1 150 150 150 A-2 150 epoxy resin B-1 60 60 60 60 B-2 10 10 10 10 B-3 30 30 30 30 Hardener C 2.4 2.4 2.4 2.4 curing accelerator D. 2.4 2.4 2.4 2.4 Filler E-1 0 0 320 160 E-2 320 320 0 160 coupling agent f 2 2 2 2 Colorant G 17.9 17.9 17.9 17.9

The prepared 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 having a thickness of 40 μm. Next, the 2nd release film was stuck on the protective film forming film, and the sheet|seat for protective film formation of a three-layer structure in which the peeling film was formed on both surfaces of the protective film forming film was obtained. Regarding the sticking conditions, the temperature was 60° C., the pressure was 0.4 MPa, and the speed was 1 m/min.

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

(Shear strength of the interface between the protective film and the silicon wafer dipped in 2-aminoethanol) A dicing tape (Adwill D-676H manufactured by LINTEC Corporation) was attached to the polished surface of a #2000-polished silicon wafer (diameter 200 mm, thickness 350 μm), and the silicon wafer was cut using a dicing device (DFD6362 manufactured by DISCO Corporation). The circle was cut into a size of 30 mm×30 mm, and the silicon wafer was obtained by peeling off the dicing tape.

The sheet|seat for protective film formation of an Example and a comparative example was cut|disconnected into width 5mm, and length 30mm. Peel off the second release film from the cut protective film forming sheet, and attach the exposed protective film forming film to the obtained silicon wafer (30mm×30mm) at a speed of 0.3m/min while heating to 70°C. ) central portion. Next, the first peeling film was peeled off, and the protective film forming film was cured by heating (130° C., 2 hours) to obtain a shear film in which a protective film with a width of 5 mm was formed in the center of a silicon wafer (30 mm×30 mm). A wafer with a protective film for strength measurement.

The obtained wafer with a protective film was immersed in a cleaning tank of an ultrasonic cleaner (manufactured by SHARP CORPORATION, UT-206H) filled with 2-aminoethanol, and in this state, irradiated at 23° C. for 15 minutes with a frequency of 37 kHz. ultrasound. After ultrasonic irradiation, take the wafer with protective film out of the 2-aminoethanol, rinse the 2-aminoethanol attached to the surface with distilled water for 2 seconds, wipe off the distilled water and let it stand for 10 minutes, by the method shown below The shear strength at room temperature (23° C.) was measured.

Using a multifunctional bond strength tester ("DAGE4000" manufactured by Nordson Advanced Technology K.K.), under the condition of 23°C, using a shear tool (shear tool), under the following conditions, only the protection in the wafer with the protection film The film (at a position 5 μm above the interface between the protective film and the wafer) exerts a force. A force was applied to the surface of the protective film at a speed of 200 μm/s so that the short sides of the protective film were perpendicular to the direction of travel of the shearing tool. Then, the force applied from the edge of the wafer with a protective film (0 mm) to a position 15 mm away from the end (half position of the wafer) was measured, and the measured value obtained from the start of the measurement to 5 mm (first half measured value), and obtain the maximum value from the measured values of the remaining second half (from 5 mm to 15 mm). This measurement was performed for three samples in each Example and Comparative Example, and the average value of the obtained maximum values was defined as the shear strength (N/5 mm). The results are shown in Table 2.

(Contact angle of 2-aminoethanol on the surface of the protective film) Peel off the second release film from the protective film forming sheets of Examples and Comparative Examples, and attach the exposed protective film forming film to a #2000 polished sheet at a speed of 0.3 m/min while heating to 70°C. The grinding surface of a silicon wafer (diameter 200mm, thickness 350μm). Furthermore, the 1st release film was peeled off from the protective film forming film, and the protective film forming film was exposed. The silicon wafer with the protective film forming film attached was heated at 130° C. for 2 hours in an oven under an air atmosphere, and the protective film forming film was formed into a protective film, thereby producing a wafer with a protective film. For the wafer with a protective film, the contact angle of 2-aminoethanol on the surface of the protective film was measured as follows. The contact angle when 0.2 μL of 2-aminoethanol was dropped on the surface of the protective film was measured using an automatic contact angle meter (“DSA100” manufactured by KRUSS) in an environment of 23° C. and a relative humidity of 50%. This measurement was performed on 10 samples in each of Examples and Comparative Examples, and the average value of the measured values was defined as the contact angle of 2-aminoethanol. The results are shown in Table 2.

(Gloss change rate of the protective film surface before and after immersion in 2-aminoethanol) Peel off the second release film from the protective film forming sheets of Examples and Comparative Examples, and attach the exposed protective film forming film to a #2000 polished sheet at a speed of 0.3 m/min while heating to 70°C. The grinding surface of a silicon wafer (diameter 200mm, thickness 350μm). Furthermore, the 1st release film was peeled off from the protective film forming film, and the protective film forming film was exposed.

The silicon wafer with the protective film forming film attached was heated at 130° C. for 2 hours in an oven under an air atmosphere, and the protective film forming film was formed into a protective film, thereby producing a wafer with a protective film. About the wafer with a protective film, the glossiness value before immersion in 2-aminoethanol at room temperature (23 degreeC) was measured by the method shown below.

In addition, the wafer with the protective film was immersed in the cleaning tank of an ultrasonic cleaner (manufactured by SHARP CORPORATION, UT-206H) filled with 2-aminoethanol, and irradiated with ultrasonic waves at a frequency of 37 kHz at 23°C for 15 minutes in this state. . After irradiating ultrasonic waves, take the wafer with the protective film out of the 2-aminoethanol, rinse the 2-aminoethanol attached to the surface with distilled water for 2 seconds, wipe off the distilled water, and let it stand for 10 minutes. Circle, the gloss value after immersion in 2-aminoethanol at room temperature (23 degreeC) was measured by the method shown below.

Using a gloss meter (manufactured by NIPPON DENSHOKU INDUSTRIES Co., Ltd., product name "VG 2000"), according to JIS Z 8741, light is incident on the surface of the protective film opposite to the surface in contact with the wafer, and the specular surface is measured. Glossiness, the value of the specular glossiness is used as the glossiness value of the protective film. Set the incident angles to 20∘, 45∘, 60∘, and 85∘. For the three wafers with a protective film in each example and comparative example, this measurement was performed before and after immersion in 2-aminoethanol, and the average value of the 12 gloss values before immersion Let it be the glossiness value before immersion in 2-aminoethanol, and let the average value of 12 glossiness values after immersion be the glossiness value after immersion in 2-aminoethanol.

Calculate the change rate of gloss before and after immersion in 2-aminoethanol from the gloss value before immersion in 2-aminoethanol and the gloss value after immersion in 2-aminoethanol [(glossiness after immersion in 2-aminoethanol value/gloss value before immersion in 2-aminoethanol)×100]. The results are shown in Table 2.

(Young's modulus and elongation at break of the protective film dipped in 2-aminoethanol) A plurality of produced protective-film-forming films were laminated to produce a laminate of protective-film-forming films having a total thickness of 200 μm. This laminate was heated at 130° C. for 2 hours to cure the protective film-forming film to obtain a laminate of a protective film.

The obtained laminated body of the protective film was die-cut (cut) into a size of 15 mm×50 mm to prepare a measurement sample. The prepared measurement sample was immersed in a cleaning tank of an ultrasonic cleaner (manufactured by Sharp Corporation, UT-206H) filled with 2-aminoethanol, and irradiated with ultrasonic waves at a frequency of 37 kHz at 23° C. for 15 minutes in this state. After irradiating ultrasonic waves, take out the laminated body of the protective film from 2-aminoethanol, rinse the 2-aminoethanol adhering to the surface with distilled water for 2 seconds, wipe off the distilled water, and let it stand for 10 minutes. For the measurement sample, use The Young's modulus at room temperature (23° C.) was measured by the method shown below.

Using a precision universal testing machine (device name "AUTOGRAPH AG-IS" manufactured by SHIMADZU CORPORATION), according to JIS K 7127, set the gap between the chucks to 30mm (that is, the 10mm at both ends of the test sample is the chuck portion (non-measurement portion)) , The tensile speed was set at 50 mm/min, the tensile test was performed in an environment of 23° C. and a relative humidity of 50%, and the Young’s modulus (MPa) was measured for the sample for measurement after immersion. The results are shown in Table 1.

In addition, when measuring the Young's modulus of the measurement sample, the elongation at break (%) of the measurement sample after immersion was obtained from the elongation of the measurement sample when the measurement sample was broken. The results are shown in Table 2. In addition, hold (clamp) two places of the measurement sample with a distance of 30 mm, and based on the length of the measurement sample at this time in the stretching direction, when the measurement sample is stretched until it breaks, the corresponding When the elongation compared to the standard is ΔLmm, the elongation at break can be calculated using the following formula. Elongation at break (%)=[ΔL(mm)/30(mm)]×100

(Adhesion reliability after cleaning flux) First, the second peeling film was peeled off from the protective film forming sheets of Examples and Comparative Examples, and the exposed protective film forming film was attached at a speed of 0.3 m/min while heating to 70° C. The lapping surface of a lapped silicon wafer (diameter 200 mm, thickness 350 μm). Furthermore, the 1st release film was peeled off from the protective film forming film, and the protective film forming film was exposed. The silicon wafer with the protective film forming film attached was heated at 130° C. for 2 hours in an oven under an air atmosphere, and the protective film forming film was formed into a protective film, thereby producing a wafer with a protective film.

Next, stick a dicing tape (Adwill D-676H manufactured by LINTEC Corporation) on the surface of the protective film, and use a dicing device (DFD6362 manufactured by DISCO Corporation) to cut the silicon wafer with the protective film into a size of 3 mm × 3 mm. Peel it off from the dicing tape to obtain a silicon wafer with a protective film.

Using a wafer with a protective film cleaned with 2-aminoethanol as a flux cleaner, the adhesion reliability of the protective film was evaluated by imitating the technique used when mounting semiconductor wafers. That is, 25 wafers with a protective film after cleaning with 2-aminoethanol were placed in a thermal shock device ("TSE-11-A" manufactured by ESPEC CORP.), and repeated 1000 times. After holding at -65°C for 10 minutes , Keep at 150°C for 10 minutes in a cold and hot cycle.

Next, all the wafers with the protective film were taken out from the thermal shock device, and the cross-section of the semiconductor wafer with the protective film was observed using a scanning ultrasonic flaw detector ("D9600 ^TM CSAM" manufactured by Sonoscan Corporation) to confirm the gap between the silicon wafer and the protective film. Check whether there is any floating or peeling of the joint between them, and confirm whether there is any crack in the silicon wafer. And, the number of wafers with a protective film in which at least one of the above-mentioned floating, peeling, and cracks occurred was counted, and when the number (NG number) was 1 or less, it was determined that the reliability was acceptable (A) , when the number is 2 or more, it is determined that the reliability is unacceptable (B). The results are shown in Table 2.

[Table 2] Example 1 Example 2 Comparative example 1 Comparative example 2 protective film After soaking in 2-aminoethanol Shear Strength[N/5mm] 40 35 30 32 Young's modulus [MPa] 740 880 1280 1100 Elongation at break[%] 20 16 8 12 Before and after dipping in 2-aminoethanol Gloss change rate[%] 111 107 125 121 2-aminoethanol contact angle[∘] 44 49 60 57 Chip with protective film Adhesion reliability test after flux cleaning The number of cracks 0/25 1/25 3/25 2/25 Eligibility A A B B

From Table 2, it can be confirmed that when the shear strength of the interface between the protective film dipped in 2-aminoethanol and the silicon wafer is 33 N/5mm or more, the reliability of the wafer with the protective film is high.

1: Protective film 4: Adhesive sheet 5,42: Adhesive layer 6a: Wafer 6b: Convex electrode 7: Ring frame 10: Protective film forming film 10a: main surface 10b: Another main face 14: cut 16: Protective film forming film 17: useless department 21: The first release film 22: Second release film 41: Substrate 51,52: sheet for forming protective film 61,62: Composite sheets for protective film formation 70:Wafer with protective film

FIG. 1 is a schematic cross-sectional view of an example of a wafer having a protective film obtained by forming a protective film-forming film according to the present embodiment as a protective film. Fig. 2A is a schematic cross-sectional view of an example of the sheet for forming a protective film according to this embodiment. Fig. 2B is a schematic cross-sectional view of another example of the sheet for forming a protective film according to this embodiment. Fig. 3A is a schematic cross-sectional view of an example of the composite sheet for forming a protective film according to this embodiment. 3B is a schematic cross-sectional view of another example of the composite sheet for forming a protective film according to this embodiment. 4A is a schematic cross-sectional view showing a state in which an example of the sheet for forming a protective film according to the present embodiment is punched. FIG. 4B is a schematic cross-sectional view showing a state in which another example of the sheet for forming a protective film according to the present embodiment has been punched. 5A is a schematic cross-sectional view for explaining the step of attaching the sheet for forming a protective film according to this embodiment to a wafer. 5B is a schematic cross-sectional view illustrating a step of attaching the protective film-forming composite sheet of the present embodiment to a wafer. FIG. 6 is a schematic cross-sectional view illustrating a step of singulating a wafer with a protective film. FIG. 7 is a schematic cross-sectional view illustrating a step of disposing a wafer with a protective film on a substrate.

1: Protective film

6a: Wafer

6b: Convex electrode

70:Wafer with protective film

Claims (9)

A protective film forming film, which is a protective film forming film for forming a protective film, wherein, The shear strength of the interface between the protective film and the silicon wafer dipped in 2-aminoethanol is above 33N/5mm. The protective film forming film according to claim 1, wherein, The contact angle of 2-aminoethanol on the surface of the protective film is less than 55∘. The protective film forming film according to claim 1 or 2, wherein, The ratio of the gloss value of the surface of the protective film after immersion in 2-aminoethanol to the gloss value of the surface of the protective film before immersion in 2-aminoethanol is 40% or more and less than 130%. According to the protective film forming film according to any one of claims 1 to 3, wherein, The Young's modulus of the protective film dipped in 2-aminoethanol is less than 1000MPa. According to the protective film forming film according to any one of claims 1 to 4, wherein, The elongation at break of the protective film dipped in 2-aminoethanol was 15% or more. A protective film forming sheet comprising the protective film forming film according to any one of claims 1 to 5 and a release film arranged on at least one main surface of the protective film forming film. A composite sheet for forming a protective film comprising the protective film forming film according to any one of claims 1 to 5 and a support sheet supporting the protective film forming film. A method of manufacturing a device, comprising: a step of attaching the protective film-forming film of the protective film-forming sheet described in claim 6 or the protective film-forming film of the protective film-forming composite sheet described in claim 7 to the back surface of the workpiece, the step of making the attached protective film forming film into a protective film, The step of singulating the workpiece having a protective film or a protective film forming film on the back surface to obtain a plurality of workpieces having a protective film or a protective film forming film, A step of arranging the processed object of the workpiece with a protective film or a protective film forming film on the substrate by contacting it with flux, a step of heating the substrate and the workpiece of the workpiece with the protective film or the protective film forming film arranged on the substrate, and A step of cleaning the substrate on which the processed object of the workpiece with a protective film is arranged with a flux cleaning agent. The method of manufacturing a device according to claim 8, which includes the step of performing laser marking on the protective film or the protective film forming film.

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