JP2017011197A - Protective film forming film, protective film forming sheet and manufacturing method of workpiece or processed product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protective film forming film and a protective film forming sheet with which the rear surface of a workpiece such as a semiconductor wafer and a processed product such as a semiconductor chip is protected and a protective film for improving the appearance thereof can be formed, and a method for manufacturing a workpiece or a processed product using the protective film forming film or the protective film forming sheet.SOLUTION: There are provided: a protective film forming film 1 containing fillers that have an average particle size of 0.2 μm or more, and having a light transmittance at a wavelength of 550 nm of 10% or less; a protective film forming sheet 3 including a pressure sensitive adhesive sheet 4 comprising an adhesive layer 42 laminated on one surface side of a base material 41 and the protective film forming film 1 laminated on an adhesive layer 42 side of the pressure sensitive adhesive sheet 4; and a method for manufacturing a workpiece or a processed product for forming a protective film on a workpiece or a processed product obtained by dividing and processing the workpiece, using the protective film forming film 1 or the protective film forming sheet 3.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a protective film-forming film and a protective film-forming sheet capable of forming a protective film on a workpiece such as a semiconductor wafer or a workpiece (for example, a semiconductor chip) obtained by processing the workpiece, and a workpiece using these Or it is related with the manufacturing method of a processed material.

  In recent years, a semiconductor device is manufactured by a mounting method called a face-down method. In this method, when a semiconductor chip having a circuit surface on which electrodes such as bumps are formed is mounted, the circuit surface side of the semiconductor chip is bonded to a chip mounting portion such as a lead frame. Therefore, the back surface side of the semiconductor chip on which no circuit is formed is exposed.

  For this reason, a protective film made of a hard organic material is often formed on the back side of the semiconductor chip to protect the semiconductor chip. This protective film is formed using, for example, a film for semiconductor back surface or a dicing tape-integrated wafer back surface protective film as disclosed in Patent Document 1.

  The protective film may be used as a member for displaying information on a workpiece (for example, a semiconductor wafer) or a workpiece (for example, a semiconductor chip) provided with the protective film. That is, there is a case where a printing process is performed in which unevenness is formed on the surface of the protective film so that information relating to a workpiece or a workpiece is displayed in a visible manner. This printing process is usually performed by irradiating the surface of the protective film with a laser.

  In this regard, the film for semiconductor back surface in Patent Document 1 has a light transmittance of 20% or less at a wavelength of 532 nm or 1064 nm. This enables printing processing by laser light irradiation and prevents the semiconductor element from being adversely affected by the laser light.

JP 2012-28396 A

  On the other hand, a workpiece such as a semiconductor wafer may be subjected to a so-called back grinding process in which the back surface opposite to the circuit forming surface is ground in a stage before protection. Finally, grinding marks remain on the back surface of the workpiece such as a semiconductor chip. And, for example, when visually recognizing the print on the protective film provided on the workpiece or workpiece as described above, this grinding mark may also be visually recognized through the protective film, and the appearance may be impaired. There was a problem that there was. If the protective film is difficult to transmit, for example, light having a wavelength of 550 nm, which is approximately the center of the visible light region, the grinding marks are concealed by the protective film (protective film forming film) and are hardly visible. That is, the protective film is also expected to have a function of improving the appearance of a workpiece or a workpiece. However, the film for semiconductor back surface disclosed in Patent Document 1 does not necessarily have a sufficient function to improve such an appearance.

  The present invention has been made in view of the above circumstances, and can protect a back surface of a workpiece such as a semiconductor wafer or a workpiece such as a semiconductor chip, and can form a protective film for improving the appearance. It is an object of the present invention to provide a film for forming and a sheet for forming a protective film, and a method for producing a workpiece or a workpiece using these.

  When the average particle diameter of the filler contained in the protective film-forming film is larger than a predetermined value, the present inventors, for example, without using a colorant such as a pigment, and the protective film-forming film and the protective film The present inventors have found that the light transmittance at a wavelength of 550 nm of the film is remarkably lowered and that the above problems can be solved, and the present invention has been completed.

In order to solve the above problems, the present invention employs the following configuration.
[1]. A protective film-forming film containing a filler, wherein the filler has an average particle size of 0.2 μm or more and a light transmittance of a wavelength of 550 nm of 10% or less.
[2]. The protective film-forming film according to [1], wherein the light transmittance at a wavelength of 1250 nm is 40% or more.
[3]. The film for forming a protective film according to [1] or [2], wherein the content of the colorant in the film for forming a protective film is 3% by mass or less.
[4]. The protective film-forming film according to any one of [1] to [3], wherein the protective film-forming film contains an organic pigment.

[5]. The film for forming a protective film according to any one of [1] to [4], wherein the film for forming a protective film contains an epoxy resin.
[6]. The film for forming a protective film according to [5], wherein the epoxy resin includes at least a liquid epoxy resin at 23 ° C. and 1 atm.
[7]. The epoxy resin consists only of the liquid epoxy resin, or the epoxy resin contains the liquid epoxy resin and a solid epoxy resin at 23 ° C. and 1 atm, and the liquid epoxy resin and the solid epoxy resin The film for forming a protective film according to [6], wherein the ratio of the content of the liquid epoxy resin to the total content of the epoxy resin is 25% by mass or more and less than 100% by mass.

[8]. The protective sheet according to any one of [1] to [7], wherein the pressure-sensitive adhesive sheet has a pressure-sensitive adhesive layer laminated on one surface side of the substrate, and the pressure-sensitive adhesive layer is laminated on the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive sheet. A protective film-forming sheet comprising a film-forming film.
[9]. Using the protective film-forming film according to any one of [1] to [7] or the protective film-forming sheet according to [8], a workpiece or a workpiece obtained by dividing the workpiece into pieces. A method for producing a workpiece or a workpiece, wherein a protective film is formed on the workpiece.
[10]. Irradiating laser light in the infrared region so that the division processing is focused on a focal point set in the workpiece, a modified layer is formed inside the workpiece, and the workpiece having the modified layer formed thereon The method for manufacturing a workpiece or workpiece according to [9], wherein the workpiece or workpiece is processed by applying a force and dividing the workpiece on which the modified layer is formed to obtain a plurality of pieces as a workpiece.
[11]. The method of manufacturing a workpiece or workpiece according to [9] or [10], wherein the workpiece is a semiconductor wafer and the workpiece is a semiconductor chip.

  ADVANTAGE OF THE INVENTION According to this invention, about workpieces, such as a semiconductor wafer, and workpieces, such as a semiconductor chip, while protecting the back surface, the film for protective film formation which can form the protective film for improving an external appearance, and a sheet for protective film formation As well as a method of manufacturing a workpiece or workpiece using these.

It is sectional drawing of the sheet | seat for protective film formation which concerns on one Embodiment of this invention. It is sectional drawing of the sheet | seat for protective film formation which concerns on other one Embodiment of this invention. It is sectional drawing of the sheet | seat for protective film formation which concerns on another one Embodiment of this invention. It is sectional drawing which shows the usage example of the sheet | seat for protective film formation which concerns on one Embodiment of this invention, specifically the 1st laminated structure. It is the imaging data of the protective film printed in Example 1. It is the imaging data of the protective film printed in Reference Example 1. It is the imaging data of the protective film printed in Reference Example 3.

Hereinafter, embodiments of the present invention will be described.
[Protective film forming film]
The protective film-forming film according to this embodiment is for forming a protective film on a workpiece or a workpiece obtained by processing the workpiece. This protective film is composed of a protective film-forming film, preferably a cured protective film-forming film. Examples of the workpiece include a semiconductor wafer, and examples of the workpiece obtained by processing the workpiece include a semiconductor chip. However, the present invention is not limited to these. When the work is a semiconductor wafer, the protective film is formed on the back side of the semiconductor wafer (the side on which no electrodes such as bumps are formed).

1. Material It is preferable that the protective film-forming film contains an uncured curable adhesive. In this case, after a workpiece such as a semiconductor wafer is superimposed on the protective film forming film, the protective film can be firmly adhered to the work by curing the protective film forming film, and the protective film having durability Can be formed on a chip or the like.

  It is preferable that the protective film-forming film has adhesiveness at room temperature or exhibits adhesiveness by heating. Thereby, when superposing | stacking workpiece | work, such as a semiconductor wafer, on the film for protective film formation as mentioned above, both can be bonded. Therefore, positioning can be reliably performed before the protective film-forming film is cured.

  The curable adhesive constituting the protective film-forming film having the above properties preferably contains a curable component and a binder polymer component. As the curable component, a thermosetting component, an energy ray curable component, or a mixture thereof can be used, but it is particularly preferable to use a thermosetting component. This is because when the protective film-forming film has a light transmittance as described later, it is unsuitable for ultraviolet curing and is preferably thermosetting.

Examples of the thermosetting component include epoxy resins, phenol resins, melamine resins, urea resins, polyester resins, urethane resins, acrylic resins, polyimide resins, benzoxazine resins, and mixtures thereof. Among these, an epoxy resin, a phenol resin, and a mixture thereof are preferably used.
A thermosetting component can be used individually by 1 type or in combination of 2 or more types.

  Epoxy resins have the property of forming a three-dimensional network upon heating and forming a strong film. As such an epoxy resin, conventionally known various epoxy resins are used, and there are cases where the epoxy resin is liquid (including highly viscous liquid) at 23 ° C. and 1 atm (hereinafter referred to as “liquid epoxy resin”). And epoxy resins that are solid (including semi-solid) at 23 ° C. and 1 atm (hereinafter sometimes referred to as “solid epoxy resins”). When the liquid epoxy resin is specifically described, it means an epoxy resin having a viscosity at 25 ° C. and 1 atm of 40 Pa · s or less. In the present embodiment, any one of these may be used, but at least a liquid epoxy resin is preferably used. In this case, the epoxy resin may be composed only of a liquid epoxy resin, or a liquid epoxy resin and a solid epoxy resin may be blended and used.

  As an epoxy resin which is liquid at 23 ° C. and 1 atm, those having a molecular weight of 300 to 500 are preferable, and those having a molecular weight of 330 to 400 are particularly preferable. Moreover, it is preferable that the epoxy equivalent of liquid epoxy fat is 50-5000 g / eq, and it is especially preferable that it is 1002000 g / eq.

  On the other hand, the epoxy resin solid at 23 ° C. and 1 atm preferably has a molecular weight of 1000 to 6000, particularly preferably a molecular weight of 1400 to 4000. Moreover, it is preferable that the softening point measured by the ring and ball method of the solid epoxy resin is 50-150 degreeC, and it is especially preferable that it is 65-130 degreeC. Furthermore, the epoxy equivalent of the solid epoxy resin is preferably 50 to 5000 g / eq, and particularly preferably 100 to 2000 g / eq.

  Specific examples of the epoxy resin include glycidyl ethers of phenols such as bisphenol A, bisphenol F, resorcinol, phenyl novolac, and cresol novolac; glycidyl ethers of alcohols such as butanediol, polyethylene glycol, and polypropylene glycol; phthalic acid Glycidyl ether of carboxylic acid such as isophthalic acid and tetrahydrophthalic acid; glycidyl type or alkyl glycidyl type epoxy resin in which active hydrogen bonded to nitrogen atom such as aniline isocyanurate is substituted with glycidyl group; vinylcyclohexane diepoxide, 3, 4-epoxycyclohexylmethyl-3,4-dicyclohexanecarboxylate, 2- (3,4-epoxy) cyclohexyl-5,5-spiro (3,4-epoxy As the sheet) cyclohexane -m- dioxane, carbon in the molecule - epoxy is introduced by for example oxidation to carbon double bond include a so-called alicyclic epoxides. In addition, an epoxy resin having a biphenyl skeleton, a dicyclohexadiene skeleton, a dicyclopentadiene skeleton, a naphthalene skeleton, or the like can also be used.

  Among these, bisphenol glycidyl type epoxy resins, o-cresol novolac type epoxy resins, phenol novolak type epoxy resins, and dicyclopentadiene type epoxy resins are preferably used. These epoxy resins can be used individually by 1 type or in combination of 2 or more types.

  When blending and using a liquid epoxy resin and a solid epoxy resin, the ratio of the content of the liquid epoxy resin to the total content of the liquid epoxy resin and the solid epoxy resin is preferably 25% by mass or more and less than 100% by mass. 30 to 90% by mass is more preferable, and 35 to 80% by mass is particularly preferable. When the content ratio of the liquid epoxy resin is 25% by mass or more, it becomes easy to control the mirror glossiness of the protective film formed from the protective film-forming film to a high value, and the print visibility of the protective film is improved. It can be further increased. In the present specification, “print visibility” of the protective film means ease of visual recognition of information based on the unevenness formed on the surface of the protective film by printing. In addition, it may be easy to control the light transmittance of a predetermined wavelength to a preferable range described later. In this case, it is possible to enjoy further effects such as easy division of the workpiece and easy infrared inspection of the workpiece. When a liquid epoxy resin and a solid epoxy resin are blended and used, it becomes easy to separate the processed product from the release sheet together with the protective film forming film in the protective film forming sheet described later.

  When using an epoxy resin, it is preferable to use a thermally activated latent epoxy resin curing agent in combination as an auxiliary agent. The thermally activated latent epoxy resin curing agent is a type of curing agent that does not react with the epoxy resin at room temperature but is activated by heating at a certain temperature or more and reacts with the epoxy resin. The heat activated latent epoxy resin curing agent is activated by a method in which active species (anions and cations) are generated by a chemical reaction by heating; the epoxy resin is stably dispersed in the epoxy resin at around room temperature and is heated at a high temperature. There are a method of initiating a curing reaction by dissolving and dissolving with a solvent; a method of starting a curing reaction by elution at a high temperature with a molecular sieve encapsulated type curing agent; a method using a microcapsule and the like.

  Specific examples of the thermally activated latent epoxy resin curing agent include various onium salts, high melting point active hydrogen compounds such as dibasic acid dihydrazide compounds, dicyandiamides, amine adduct curing agents, and imidazole compounds. These thermally activated latent epoxy resin curing agents can be used singly or in combination of two or more. The thermally activated latent epoxy resin curing agent as described above is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts by mass, and still more preferably 0.8 to 100 parts by mass of the epoxy resin. It is used at a ratio of 3 to 5 parts by mass.

  As the phenolic resin, a condensate of phenols such as alkylphenol, polyhydric phenol, naphthol and aldehydes is used without particular limitation. Specifically, phenol novolak resin, o-cresol novolak resin, p-cresol novolak resin, tert-butylphenol novolak resin, dicyclopentadiene cresol resin, polyparavinylphenol resin, bisphenol A type novolak resin, or modified products thereof Etc. are used.

  The phenolic hydroxyl group contained in these phenolic resins can easily undergo an addition reaction with the epoxy group of the epoxy resin by heating to form a cured product having high impact resistance. For this reason, you may use together an epoxy resin and a phenol-type resin.

  The binder polymer component can give an appropriate tack to the protective film-forming film and improve the operability of the protective film-forming sheet. The weight average molecular weight of the binder polymer is preferably 50,000 to 2,000,000, more preferably 100,000 to 1,500,000, and particularly preferably 200,000 to 1,000,000. In addition, the weight average molecular weight (Mw) of the binder polymer component in this specification is a value in terms of standard polystyrene measured by a gel permeation chromatography method (GPC method), and details of the measuring method are described in the examples described later. Show.

When the weight average molecular weight of the binder polymer is too low, film formation of the protective film-forming film becomes insufficient, and when it is too high, compatibility with other components is deteriorated, and as a result, uniform film formation is prevented. As such a binder polymer, for example, an acrylic polymer, a polyester resin, a phenoxy resin, a urethane resin, a silicone resin, a rubber polymer, and the like are used, and an acrylic polymer is particularly preferably used.
A binder polymer can be used individually by 1 type or in combination of 2 or more types.

As the acrylic polymer, for example, as a monomer component, a structural unit derived from a (meth) acrylic acid alkyl ester, and a structural unit derived from a (meth) acrylic acid derivative other than the (meth) acrylic acid alkyl ester, The (meth) acrylic acid ester copolymer which consists of these is mentioned.
In this specification, “(meth) acrylic acid” is a concept including both “acrylic acid” and “methacrylic acid”. The same applies to other similar terms.

  The (meth) acrylic acid alkyl ester is preferably a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 18 carbon atoms, such as methyl (meth) acrylate and ethyl (meth) acrylate. , Propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, n-octyl (meth) acrylate, (meth) acrylic acid Isooctyl, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate ((meth) ) Lauryl acrylate), tridecyl (meth) acrylate, tetra (meth) acrylate Sil (myristyl (meth) acrylate), pentadecyl (meth) acrylate, hexadecyl (meth) acrylate (palmityl (meth) acrylate), heptadecyl (meth) acrylate, octadecyl (meth) acrylate ((meth) (Meth) acrylic acid alkyl esters in which the alkyl group is a chain, such as stearyl acrylate) or isooctadecyl (meth) acrylate (isostearyl (meth) acrylate); isobornyl (meth) acrylate, (meth) acrylic And (meth) acrylic acid cycloalkyl esters such as acid dicyclopentanyl.

  Examples of the (meth) acrylic acid derivative include (meth) acrylic acid; glycidyl group-containing (meth) acrylic acid ester such as glycidyl (meth) acrylate; hydroxymethyl (meth) acrylate, (meth) acrylic acid 2 -Hydroxyethyl, hydroxyl-containing (meth) acrylic acid esters such as 2-hydroxypropyl (meth) acrylate, and the like can be mentioned.

  Among them, when a glycidyl group is introduced into an acrylic polymer using glycidyl methacrylate as a structural unit, the compatibility with the epoxy resin as the thermosetting component described above is improved, and the protective film-forming film is cured. Glass transition temperature (Tg) becomes high and heat resistance improves. Moreover, when a hydroxyl group is introduced into an acrylic polymer using 2-hydroxyethyl acrylate or the like as a constituent unit among the above, adhesion to a workpiece and physical properties of an adhesive can be controlled.

  When an acrylic polymer is used as the binder polymer, the weight average molecular weight of the polymer is preferably 100,000 or more, more preferably 150,000 to 1,000,000. The glass transition temperature of the acrylic polymer is preferably 20 ° C. or lower, more preferably about −70 to 0 ° C., and has adhesiveness at room temperature (23 ° C.).

  In the curable adhesive, the blending ratio of the thermosetting component and the binder polymer component is preferably 50 to 1500 parts by mass, more preferably 70 to 1500 parts by mass with respect to 100 parts by mass of the binder polymer component. 1000 mass parts, More preferably, 80-800 mass parts is mix | blended. When the thermosetting component and the binder polymer component are blended in such a ratio, an appropriate tack is exhibited before curing, and the sticking operation can be stably performed. A membrane is obtained.

  The protective film-forming film contains a filler, and the average particle size of the filler contained in the protective film-forming film is 0.2 μm or more. Thereby, the protective film formed from the protective film-forming film and the protective film-forming film has a light transmittance of 10% or less at a wavelength of 550 nm, for example, even if the amount of a colorant such as a pigment is small, or Even if no colorant is used, it becomes difficult to transmit light. Thus, when the light transmittance of the protective film is low, the workpiece or workpiece provided with the protective film remains on the back surface of the workpiece or workpiece when visually observed from the protective film side (back side). Grinding marks that are present are hidden by the protective film and are hardly visible. That is, the said protective film can improve the external appearance of the workpiece | work or workpiece provided with this.

  In the present specification, the average particle size of the filler less than 1 μm is determined by a dynamic light scattering method using a particle size distribution measuring device (“Nanotrack Wave-UT151” manufactured by Nikkiso Co., Ltd.) unless otherwise specified. It is a measured value. Further, the average particle diameter of 1 μm or more of the filler is a value measured by a laser diffraction / scattering method using a particle size distribution measuring device (“Microtrack MT3000II” manufactured by Nikkiso Co., Ltd.) unless otherwise specified.

  Moreover, when the film for protective film formation contains a filler, while being able to maintain the hardness of the protective film after hardening high, moisture resistance can be improved. Furthermore, the thermal expansion coefficient of the protective film after curing can be brought close to the thermal expansion coefficient of the semiconductor wafer, thereby reducing the warpage of the semiconductor wafer during processing.

  As long as the above average particle size is satisfied, the specific type of filler is not limited. Examples of the filler include silica such as crystalline silica, fused silica and synthetic silica, and inorganic filler such as alumina and glass balloon. Among these, silica is preferable as the filler, and synthetic silica is more preferable. In particular, synthetic silica of the type in which an α-ray source that causes malfunction of the semiconductor device is removed as much as possible is optimal. Examples of the shape of the filler include a spherical shape, a needle shape, and an indefinite shape, and a spherical shape is preferable, and a true spherical shape is particularly preferable. When the filler is spherical or true spherical, irregular reflection of light rays hardly occurs, and control of the light transmittance spectrum profile of the protective film-forming film becomes easy.

  Moreover, as a filler added to the film for protective film formation, a functional filler is mentioned besides the said inorganic filler. As the functional filler, for example, a conductive filler in which gold, silver, copper, nickel, aluminum, stainless steel, carbon, ceramic, nickel, aluminum, or the like is coated with silver for the purpose of imparting conductivity after die bonding. And metal materials such as gold, silver, copper, nickel, aluminum, stainless steel, silicon, and germanium, and heat conductive fillers such as alloys thereof for the purpose of imparting thermal conductivity.

  As described above, the average particle diameter of the filler is 0.2 μm or more, preferably 0.25 μm or more, and more preferably 0.3 μm or more. On the other hand, the upper limit value of the average particle diameter of the filler is not particularly limited as long as the effect of the present invention is not impaired, but can be selected from any one of 0.7 μm, 0.65 μm, 0.6 μm, 0.55 μm, and the like. . For example, when the average particle size of the filler is 0.4 μm or less, it is easy to increase the specular gloss of the protective film formed from the protective film-forming film, and the print visibility of the protective film can be improved. In addition, it may be easy to control the light transmittance of a predetermined wavelength to a preferable range described later. In this case, it is possible to enjoy further effects such as easy division of the workpiece and easy infrared inspection of the workpiece.

  The blending amount (content) of the filler in the protective film-forming film is preferably 10% by mass or more and 80% by mass or less, more preferably 20% by mass or more and 70% by mass or less, and more preferably 30% by mass or more. It is more preferably 65% by mass or less, particularly preferably 40% by mass or more and 60% by mass or less, and most preferably 50% by mass or more and 60% by mass or less. The effect which improves the external appearance of a workpiece | work or a workpiece becomes higher that the compounding quantity of a filler is 10 mass% or more. Moreover, it may become easy to control the light transmittance of the predetermined wavelength of the film for protective film formation to the preferable range mentioned later. On the other hand, when the blending amount of the filler is 80% by mass or less, it becomes easy to improve the printing visibility of the protective film, or the light transmittance at a predetermined wavelength of the protective film-forming film falls within a preferable range described later. It becomes easy to control.

  A filler can be used individually by 1 type or in combination of 2 or more types.

The protective film-forming film may contain a colorant.
As the colorant, for example, known pigments such as inorganic pigments, organic pigments, organic dyes and the like can be used. From the viewpoint of improving the controllability of light transmittance, the colorant is an organic colorant. It is preferable to contain. From the viewpoint of increasing the chemical stability of the colorant (specifically, elution resistance, resistance to color transfer, and little change over time are exemplified), the colorant preferably contains a pigment. More preferably, it is made of a pigment. Therefore, the colorant contained in the protective film-forming film according to this embodiment preferably contains an organic pigment, and more preferably consists of an organic pigment.

  Examples of organic pigments and organic dyes that are organic colorants include aminium dyes, cyanine dyes, merocyanine dyes, croconium dyes, squalium dyes, azurenium dyes, polymethine dyes, naphthoquinone dyes, Pyrylium dyes, phthalocyanine dyes, naphthalocyanine dyes, naphtholactam dyes, azo dyes, condensed azo dyes, indigo dyes, perinone dyes, perylene dyes, dioxazine dyes, quinacridone dyes, isoindolinone dyes Dye, quinophthalone dye, pyrrole dye, thioindigo dye, metal complex dye (metal complex dye), dithiol metal complex dye, indolephenol dye, triallylmethane dye, anthraquinone dye, dioxazine dye, naphthol Pigments Methine dyes, benzimidazolone pigments, pyranthrone pigments and threne color, and the like.

  The organic colorant may be composed of one type of material or may be composed of a plurality of types of materials. From the viewpoint of easily increasing the printing visibility of the protective film formed from the protective film-forming film, and to easily control the light transmittance at a predetermined wavelength of the protective film-forming film to a preferable range described later. From this viewpoint, it is preferable that the colorant contained in the protective film-forming film according to the present embodiment is composed of a plurality of types of materials.

  For example, when an isoindolinone dye that is a yellow pigment, a phthalocyanine dye that is a blue pigment, and a diketopyrrolopyrrole that is a red pigment are blended in an appropriate ratio, the protective film-forming film In some cases, it becomes easy to control the light transmittance of a predetermined wavelength within a preferable range described later.

  Examples of inorganic pigments include carbon black, cobalt dyes, iron dyes, chromium dyes, titanium dyes, vanadium dyes, zirconium dyes, molybdenum dyes, ruthenium dyes, platinum dyes, ITO (indium) Tin oxide) dyes, ATO (antimony tin oxide) dyes, and the like.

  The colorant in the protective film-forming film according to this embodiment may be composed of an organic colorant and an inorganic colorant.

The blending amount (content) of the colorant in the protective film-forming film is easy to increase the print visibility of the protective film formed from the protective film-forming film, taking into account the thickness of the protective film-forming film. It is preferable to set appropriately so that the light transmittance of a predetermined wavelength of the protective film-forming film is controlled within a preferable range described later. When the blending amount of the colorant in the protective film-forming film is excessively high, other physical properties of the protective film-forming film, for example, a tendency to decrease adhesion to the workpiece may be observed. In consideration of the above, it is preferable to set the blending amount.
In the present embodiment, the blending amount of the colorant in the protective film-forming film is, for example, preferably 3% by mass or less, more preferably 2.7% by mass or less, as described later. The light transmittance at a wavelength of 550 nm of the protective film-forming film is sufficiently low, and the appearance of a workpiece such as a semiconductor wafer or a workpiece such as a semiconductor chip is excellent.

  The average particle size of the colorant is not limited. The average particle diameter of the colorant is preferably set so as to enhance the printing visibility of the protective film formed from the protective film-forming film, and the light transmittance at a predetermined wavelength of the protective film-forming film will be described later. It is further preferable that the setting is made so as to facilitate the control to a preferable range. When the average particle diameter of the colorant is excessively large, it may be difficult to increase the light transmittance regardless of the wavelength. When the average particle diameter of the colorant is excessively small, there is a high possibility that a secondary problem such as difficulty in obtaining such a colorant or deterioration in handleability occurs. Therefore, the average particle diameter of the colorant is preferably 1 to 500 nm, more preferably 3 to 100 nm, and further preferably 5 to 50 nm. In addition, the average particle diameter of the colorant in this specification is a value measured by a dynamic light scattering method using a particle size distribution measuring device (manufactured by Nikkiso Co., Ltd., Nanotrack Wave-UT151).

  A coloring agent can be used individually by 1 type or in combination of 2 or more types.

The protective film-forming film may contain a coupling agent. By containing a coupling agent, after curing of the protective film-forming film, it is possible to improve the adhesion and adhesion between the protective film and the workpiece without impairing the heat resistance of the protective film, as well as water resistance. (Moisture and heat resistance) can be improved. As the coupling agent, a silane coupling agent is preferable because of its versatility and cost merit.
A coupling agent can be used individually by 1 type or in combination of 2 or more types.

Examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ- (methacryloxy). Propyl) trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-6- (aminoethyl) -γ-aminopropylmethyldiethoxysilane, N -Phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, bis (3-triethoxysilylpropyl) tetrasulfane, methyltri Methoxysilane , Methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazolesilane.
A silane coupling agent can be used individually by 1 type or in mixture of 2 or more types.

The film for forming a protective film may contain a crosslinking agent such as an organic polyvalent isocyanate compound, an organic polyvalent imine compound, or an organometallic chelate compound in order to adjust the cohesive force before curing. The protective film-forming film may contain an antistatic agent in order to suppress static electricity and improve the reliability of the chip. Furthermore, the film for forming a protective film may contain a flame retardant such as a phosphoric acid compound, a bromine compound, and a phosphorus compound in order to improve the flame retardance performance of the protective film and improve the reliability as a package.
Any of the crosslinking agents, antistatic agents and flame retardants can be used alone or in combination of two or more.

  The thickness of the protective film-forming film is preferably 3 to 300 μm, more preferably 5 to 200 μm, and more preferably 7 to 100 μm in order to effectively exert the function as the protective film. Further preferred.

2. Physical Properties (1) Transmittance The protective film-forming film according to this embodiment has a light transmittance of 10% or less at a wavelength of 550 nm. The light transmittance in this specification is a value measured without using an integrating sphere at any wavelength (for example, wavelengths 1064 nm and 1250 nm described later), and a spectrophotometer is used as a measuring instrument.

  Taking the case where the workpiece is a semiconductor chip as an example, grinding marks are usually left on the back surface of the semiconductor chip due to back grinding applied to the semiconductor wafer. When the light transmittance at a wavelength of 550 nm, which is substantially the center of the visible light region, is 10% or less as described above, the protective film-forming film is difficult to transmit visible light. Therefore, the grinding marks are concealed by the protective film-forming film (protective film) and are hardly visible by visual inspection. Thereby, the external appearance of a workpiece such as a semiconductor wafer or a workpiece such as a semiconductor chip becomes excellent.

  From the viewpoint of the grinding mark concealing property, the light transmittance at a wavelength of 550 nm of the protective film-forming film is preferably 9.5% or less, more preferably 9% or less, and 8.5% or less. More preferably it is. In addition, the lower limit of the light transmittance at a wavelength of 550 nm of the protective film-forming film is not particularly limited from the viewpoint of grinding mark concealment. On the other hand, if the light transmittance at a wavelength of 550 nm is excessively reduced for the protective film-forming film, for example, it may be difficult to set the light transmittance at a wavelength of 1064 nm described later to 50% or more. The lower limit of the light transmittance at a wavelength of 550 nm is preferably about 0.1%, and more preferably about 0.5%.

  When the protective film-forming film according to the present embodiment has a light transmittance at a wavelength of 1064 nm of 50% or more, division processing by modified layer fracture-type tensile division described below is facilitated. In the present specification, the ease of processing by the modified layer fracture type tension division is also referred to as “modified fracture processability”.

  When manufacturing a workpiece made of a piece of semiconductor chip or the like from a workpiece such as a semiconductor wafer, conventionally, the piece is cut by rotating the workpiece with a rotary blade while spraying a liquid for cleaning or the like on the workpiece. In general, division processing by blade dicing is performed. However, in recent years, a division process using a modified layer fracture type tension division that can be divided into pieces in a dry manner has been adopted. In such division processing, a laser beam in the infrared region is irradiated so as to be focused at a focal point set in the workpiece, a modified layer is formed inside the workpiece, and the workpiece on which the modified layer is formed A force is applied to the workpiece, and the work on which the modified layer is formed is divided to obtain a plurality of pieces as a workpiece. A specific example of such a division processing method is a laser having a large aperture (NA) so that a modified layer is preliminarily formed inside the workpiece while minimizing damage to the vicinity of the surface of the workpiece. Light is irradiated, and then a piece is obtained as a workpiece by applying force to the workpiece in an expanding step or the like. As a manufacturing method of the chip by the modified layer fracture type tension splitting, a stealth dicing (registered trademark) method proposed by Hamamatsu Photonics Co., Ltd. and the like can be mentioned.

  The light transmittance at a wavelength of 1064 nm of the protective film-forming film according to the present embodiment is more preferably 55% or more, further preferably 60% or more, from the viewpoint of improving the modified fracture processability. Particularly preferred is 65% or more. The upper limit of the light transmittance at a wavelength of 1064 nm of the protective film-forming film according to this embodiment is not limited from the viewpoint of improving the modified fracture processability, but is preferably 85%, for example.

  The light transmittance at a wavelength of 1250 nm of the protective film-forming film according to this embodiment is preferably 40% or more. When the light transmittance at a wavelength of 1250 nm of the protective film-forming film is 40% or more, infrared inspection described below is facilitated.

  In a semiconductor chip or the like obtained by dicing a semiconductor wafer, cracks generated by stress generated during processing, a processing tool such as a rotary blade, and other parts (including semiconductor chips and the like) in a workpiece such as a semiconductor wafer. There may be a chipping or the like generated by a collision or the like (in this specification, these may be collectively referred to as “a crack or the like”). However, depending on the light transmittance of the formed protective film, cracks and the like generated on the protective film side of the semiconductor chip cannot be found visually. A semiconductor chip with cracks that cannot be overlooked reduces the product yield. As the size of the semiconductor chip decreases, the size of such cracks that cannot be overlooked tends to decrease.

  On the other hand, when the light transmittance at a wavelength of 1250 nm of the protective film-forming film is 40% or more as described above, the infrared-transmitting property of the protective film-forming film becomes particularly good, and the protective film-forming film Infrared inspection can be performed by irradiating infrared rays from the side (or the protective film formed by the protective film-forming film). Thereby, the crack etc. in workpieces, such as a semiconductor chip, can be discovered through the film for protective film formation (protective film), and a product yield can be improved.

  From the viewpoint of enhancing the infrared transmittance of the protective film-forming film and facilitating the above inspection, the light transmittance at a wavelength of 1250 nm of the protective film-forming film according to this embodiment is more than 45%. Preferably, it is 50% or more, more preferably 55% or more. The upper limit of the light transmittance at a wavelength of 1250 nm of the protective film-forming film according to this embodiment is not particularly limited. When using a workpiece (semiconductor chip, etc.) with a protective film, the protective film-forming film has a light transmittance at a wavelength of 1250 nm of 90% or less. Operation can be prevented.

  Here, the protective film-forming film according to the present embodiment may be composed of a single layer or a plurality of layers, but it is easy to control the light transmittance as described above. It is preferable that it consists of a single layer from the surface of manufacturing cost. When the protective film-forming film is composed of a plurality of layers, it is preferable that the light transmittance is satisfied as a whole from the viewpoint of easy control of the light transmittance.

  When the protective film-forming film is made of an uncured curable adhesive, the light transmittance of the protective film-forming film hardly changes even before or after curing. Therefore, if the protective film-forming film before curing satisfies the light transmittance conditions for any of the above wavelengths, the protective film obtained by curing the protective film-forming film also has the light transmittance of the wavelength. The condition of can be satisfied.

(2) 60 degree specular gloss Gs (60 °)
The protective film formed from the protective film-forming film according to the present embodiment is 60 degrees defined in JIS Z8741: 1997 (ISO 2813: 1994) from the viewpoint that it is easy to improve the printing visibility of the protective film. The specular gloss Gs (60 °) is preferably 40% or more. In the present specification, the 60-degree specular gloss Gs (60 °) means a value measured using a gloss meter “VG 2000” manufactured by Nippon Denshoku Industries Co., Ltd. From the viewpoint of more stably increasing the printing visibility of the protective film, the 60 degree specular gloss Gs (60 °) of the protective film is preferably 50% or more, more preferably 60% or more, and 70%. More preferably, it is more preferably 80% or more. From the viewpoint of improving the printing visibility of the protective film, the upper limit value of the 60-degree specular gloss Gs (60 °) of the protective film is not particularly limited, but is preferably 95%, for example.

[Protective film forming sheet 2]
FIG. 1 is a cross-sectional view of a protective film forming sheet according to an embodiment of the present invention. As shown in FIG. 1, the protective film forming sheet 2 according to the present embodiment is laminated on the protective film forming film 1 and one surface (the lower surface in FIG. 1) of the protective film forming film 1. And a release sheet 21. However, the release sheet 21 is peeled off when the protective film forming sheet 2 is used.

The release sheet 21 protects the protective film-forming film 1 until the protective film-forming sheet 2 is used, and is not necessarily required.
The configuration of the release sheet 21 is arbitrary, and examples thereof include a plastic film in which the film itself is peelable from the protective film-forming film 1 and a film obtained by peeling the plastic film with a release agent or the like. Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene. As the release agent, silicone-based, fluorine-based, long-chain alkyl-based, and the like can be used, and among these, a silicone-based release agent that can provide inexpensive and stable performance is preferable.
Although there is no restriction | limiting in particular about the thickness of the peeling sheet 21, Usually, it is about 20-250 micrometers.

  The release sheet 21 as described above may also be laminated on the other surface (the upper surface in FIG. 1) of the protective film-forming film 1. In this case, it is preferable that the release force of one release sheet 21 is increased to obtain a heavy release release sheet, and the release force of the other release sheet 21 is reduced to provide a light release release sheet.

  In order to manufacture the protective film-forming sheet 2 according to the present embodiment, the release surface of the release sheet 21 (a surface having peelability; usually a surface subjected to a release treatment, but is not limited thereto). A protective film-forming film 1 is formed. Specifically, a coating agent for a protective film forming film containing a curable adhesive constituting the protective film forming film 1 and, if desired, further a solvent is prepared, and a roll coater, a knife coater, and a roll knife coater are prepared. Then, the protective film forming film 1 is formed by applying to the release surface of the release sheet 21 with a coating machine such as an air knife coater, die coater, bar coater, gravure coater, curtain coater, and drying.

As an example, a method for manufacturing a chip on which a protective film is formed from a semiconductor wafer as a work will be described below using the protective film forming sheet 2 according to the present embodiment.
First, the protective film forming film 1 of the protective film forming sheet 2 is attached to the back surface of the semiconductor wafer having a circuit formed on the front surface and subjected to back grinding. At this time, if desired, the protective film-forming film 1 may be heated to exhibit adhesiveness.

  Next, the release sheet 21 is peeled from the protective film-forming film 1. Thereafter, the protective film-forming film 1 is cured to form a protective film, thereby obtaining a semiconductor wafer on which the protective film is formed. When the protective film-forming film 1 is a thermosetting adhesive, the protective film-forming film 1 may be heated at a predetermined temperature for an appropriate time. In addition, you may perform hardening of the film 1 for protective film formation after either of the laser printing and division process which are demonstrated below.

  If a semiconductor wafer with a protective film is obtained as described above, the protective film is irradiated with laser light as desired to perform laser printing. Laser printing may be performed after the division processing described below.

  The dividing process may be blade dicing or modified layer breaking type tensile division. In the latter case, the semiconductor wafer on which the printed protective film is formed is placed in a laser irradiation apparatus for division processing, and after detecting the position of the surface of the semiconductor wafer covered with the protective film, the processing laser Is used to form a modified layer in the semiconductor wafer.

  A dicing sheet is affixed to the surface on the protective film side of the laminate composed of the semiconductor wafer and protective film in which the modified layer thus obtained is formed. And the force (tensile force of a main surface direction) is provided to the semiconductor wafer with a protective film by implementing the expanding process which expands a dicing sheet. As a result, the above-mentioned laminate that is adhered to the dicing sheet is divided to obtain a chip on which a protective film is formed. After that, the chip on which the protective film is formed is picked up from the dicing sheet using a pickup device.

  A workpiece such as a chip on which the protective film obtained as described above is formed has excellent print visibility depending on the configuration of the protective film, and the workpiece such as a chip is infrared via the protective film. It becomes easy to inspect and find a workpiece having cracks or the like. Furthermore, the infrared inspection through the protective film-forming film or the protective film may be facilitated for the workpiece before the division processing is performed.

[Protective film forming sheet 3, 3A]
FIG. 2 is a cross-sectional view of a protective film forming sheet according to another embodiment of the present invention. As shown in FIG. 2, the protective film-forming sheet 3 according to this embodiment includes a pressure-sensitive adhesive sheet 4 in which a pressure-sensitive adhesive layer 42 is laminated on one surface side of a substrate 41, and a pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet 4. The protective film forming film 1 laminated on the 42 side and the jig adhesive layer 5 laminated on the peripheral edge of the protective film forming film 1 opposite to the adhesive sheet 4 are provided. The jig pressure-sensitive adhesive layer 5 is a layer for bonding the protective film forming sheet 3 to a jig such as a ring frame.

  The protective film forming sheet 3 is used to form a protective film on the workpiece or a workpiece obtained by processing the workpiece while being attached to the workpiece and holding the workpiece when the workpiece is processed. It is done. This protective film is composed of a protective film-forming film 1, preferably a cured protective film-forming film 1.

  For example, the protective film forming sheet 3 is used to hold a semiconductor wafer during dicing processing of a semiconductor wafer as a workpiece and to form a protective film on a semiconductor chip obtained by dicing, but is not limited thereto. It is not a thing. In this case, the pressure-sensitive adhesive sheet 4 of the protective film forming sheet 3 is generally referred to as a dicing sheet.

1. Adhesive Sheet The adhesive sheet 4 of the protective film forming sheet 3 according to the present embodiment includes a base material 41 and an adhesive layer 42 laminated on one surface of the base material 41.

1-1. The base material 41 of the pressure-sensitive adhesive sheet 4 is not particularly limited as long as the base material 41 is suitable for workpiece processing, for example, dicing and expanding of a semiconductor wafer. Usually, a resin-based material is the main material. It is comprised from a film (henceforth "resin film").

  Specific examples of resin films include polyethylene films such as low density polyethylene (LDPE) films, linear low density polyethylene (LLDPE) films, and high density polyethylene (HDPE) films, polypropylene films, polybutene films, polybutadiene films, and polymethylpentene films. Polyolefin films such as ethylene-norbornene copolymer film and norbornene resin film; ethylene-vinyl acetate copolymer film, ethylene- (meth) acrylic acid copolymer film, ethylene- (meth) acrylic acid ester copolymer Ethylene copolymer film such as film; Polyvinyl chloride film such as polyvinyl chloride film and vinyl chloride copolymer film; Polyethylene terephthalate film, Polybutylene tele Polyester film of tallate films; polyurethane film; polyimide film; polystyrene films; polycarbonate films; fluororesin films and the like. Further, modified films such as these crosslinked films and ionomer films are also used. The substrate 41 may be a film made of one of these, or may be a laminated film in which two or more of these are combined.

  Among these, from the viewpoints of environmental safety, cost, and the like, the resin film is preferably a polyolefin film, and among them, a polypropylene film having excellent heat resistance is preferable. If it is a polypropylene film, heat resistance can be provided to the base material 41, without impairing the expandability of the adhesive sheet 4, and the pick-up property of a chip | tip. Due to the heat resistance of the base material 41, even when the protective film forming film 1 is heat-cured in a state where the protective film forming sheet 3 is attached to a work, the occurrence of loosening of the adhesive sheet 4 is suppressed. be able to.

  For the purpose of improving the adhesion with the adhesive layer 42 laminated on the surface of the base material 41, one or both surfaces may be subjected to a surface treatment such as an oxidation method or a concavo-convex method or a primer treatment as desired. it can. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone, ultraviolet irradiation treatment, and the like. And a thermal spraying method.

  The base material 41 may contain various additives such as a colorant, a flame retardant, a plasticizer, an antistatic agent, a lubricant, and a filler in the resin film.

  The thickness of the base material 41 is not specifically limited as long as it can function appropriately in each process in which the protective film forming sheet 3 is used. Preferably it is 20-450 micrometers, More preferably, it is 25-400 micrometers, Most preferably, it is the range of 50-350 micrometers.

  The breaking elongation of the base material 41 of the pressure-sensitive adhesive sheet 4 in this embodiment is preferably 100% or more as a value measured at 23 ° C. and a relative humidity of 50%, particularly preferably 200 to 1000%. . Here, the breaking elongation is an elongation ratio of the length of the test piece at the time of breaking the test piece with respect to the original length in the tensile test based on JIS K7161: 1994 (ISO 527-1 1993). The base material 41 having a breaking elongation of 100% or more is not easily broken during the expanding process, and the chips formed by cutting the workpiece can be easily separated.

  The tensile stress at 25% strain of the base material 41 of the pressure-sensitive adhesive sheet 4 in this embodiment is preferably 5 to 15 N / 10 mm, and the maximum tensile stress is preferably 15 to 50 MPa. Here, the tensile stress at 25% strain and the maximum tensile stress are measured by a test according to JIS K7161: 1994. When the tensile stress at 25% strain is 5 N / 10 mm or more and the maximum tensile stress is 15 MPa or more, the substrate 2 is bonded to the protective film-forming film 1 and then fixed to a frame body such as a ring frame. It is possible to suppress the occurrence of slack in the sheet and to prevent a conveyance error from occurring. On the other hand, when the tensile stress at 25% strain is 15 N / 10 mm or less and the maximum tensile stress is 50 MPa or less, the protective film-forming film 1 itself is prevented from peeling off from the ring frame during the expanding step. The elongation at break, the tensile stress at 25% strain, and the maximum tensile stress are values measured in the longitudinal direction of the original fabric in the base material 41.

1-2. Pressure-sensitive adhesive layer The pressure-sensitive adhesive layer 42 included in the pressure-sensitive adhesive sheet 4 of the protective film-forming sheet 3 according to the present embodiment may be made of a non-energy ray-curable pressure-sensitive adhesive or made of an energy-ray-curable pressure-sensitive adhesive. May be. As the non-energy ray curable pressure-sensitive adhesive, those having desired adhesive strength and removability are preferable, for example, acrylic pressure-sensitive adhesive, rubber-based pressure-sensitive adhesive, silicone-based pressure-sensitive adhesive, urethane-based pressure-sensitive adhesive, and polyester-based pressure-sensitive adhesive. Polyvinyl ether-based pressure-sensitive adhesives can be used. Among these, an acrylic pressure-sensitive adhesive that has high adhesion to the protective film-forming film 1 and that can effectively prevent the workpiece or workpiece from falling off in a dicing step or the like is preferable.

  On the other hand, since the adhesive strength of the energy ray curable adhesive decreases when irradiated with energy rays, when the workpiece or workpiece and the adhesive sheet 4 are desired to be separated, they are easily separated by irradiating them with energy rays. be able to.

  When the pressure-sensitive adhesive layer 42 is made of an energy ray-curable pressure-sensitive adhesive, the pressure-sensitive adhesive layer 42 in the protective film forming sheet 3 is preferably cured. A material obtained by curing an energy ray-curable pressure-sensitive adhesive usually has a high elastic modulus and high surface smoothness. Therefore, the protective film-forming film 3 in contact with a cured portion made of such a material is cured and protected. When the film is formed, the surface of the protective film that is in contact with the cured portion has high smoothness (gloss), and is excellent in appearance as a protective film for the chip. Further, when laser printing is performed on a protective film having high surface smoothness, the visibility of the printing is improved.

  The energy ray-curable pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 42 may be mainly composed of a polymer having energy ray-curability, or a polymer having no energy ray-curability and a lot of energy ray-curable properties. The main component may be a mixture with a functional monomer and / or an oligomer.

  The case where the energy ray curable pressure-sensitive adhesive is mainly composed of a polymer having energy ray curable properties will be described below.

  The polymer having energy ray curability is a (meth) acrylic acid ester (co) polymer (a) in which a functional group having energy ray curability (energy ray curable group) is introduced into the side chain (hereinafter referred to as “energy ray”). It may be referred to as “curable polymer (a)”). This energy ray curable polymer (a) includes a (meth) acrylic copolymer (a1) having a functional group-containing monomer unit, and an unsaturated group-containing compound (a2) having a substituent bonded to the functional group. Those obtained by reacting with are preferred.

  The acrylic copolymer (a1) is preferably composed of, for example, a structural unit derived from a functional group-containing monomer and a structural unit derived from a (meth) acrylate monomer or a derivative thereof.

  The functional group-containing monomer that is a constituent unit of the acrylic copolymer (a1) includes, for example, a polymerizable double bond and a functional group such as a hydroxyl group, an amino group, a substituted amino group, and an epoxy group in the molecule. It is preferable that the monomer has

  More specific examples of the functional group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like. These are used alone or in combination of two or more.

Examples of the (meth) acrylic acid ester monomer constituting the acrylic copolymer (a1) include alkyl (meth) acrylate, cycloalkyl (meth) acrylate, benzyl (alkyl group having 1 to 20 carbon atoms). For example, (meth) acrylate is used. Among these, more preferably, it is an alkyl (meth) acrylate having 1 to 18 carbon atoms in the alkyl group, and a more specific example thereof is a (meth) acrylic acid alkyl ester, Methyl acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, (meth) acrylic N-octyl acid, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate , Dodecyl (meth) acrylate (lauryl (meth) acrylate), tride (meth) acrylate , Tetradecyl (meth) acrylate (myristyl (meth) acrylate), pentadecyl (meth) acrylate, hexadecyl (meth) acrylate (palmityl (meth) acrylate), heptadecyl (meth) acrylate, (meth) Examples include octadecyl acrylate (stearyl (meth) acrylate), isooctadecyl (meth) acrylate (isostearyl (meth) acrylate), and the like.
A (meth) acrylic acid ester monomer can be used alone or in combination of two or more.

  The acrylic copolymer (a1) preferably contains 3 to 100% by mass, more preferably 5 to 40% by mass of a structural unit derived from the functional group-containing monomer, and a (meth) acrylic acid ester. The structural unit derived from a monomer or a derivative thereof is preferably contained in a proportion of 0 to 97% by mass, more preferably 60 to 95% by mass.

  The acrylic copolymer (a1) can be obtained by copolymerizing a functional group-containing monomer as described above with a (meth) acrylic acid ester monomer or a derivative thereof in a conventional manner. Alternatively, other monomers such as dimethylacrylamide, vinyl formate, vinyl acetate, and styrene may be copolymerized.

  By reacting the acrylic copolymer (a1) having the functional group-containing monomer unit with an unsaturated group-containing compound (a2) having a group bonded to the functional group, an energy beam curable polymer (a) Is obtained.

  The said group which an unsaturated group containing compound (a2) has can be suitably selected according to the kind of functional group of the functional group containing monomer unit which an acrylic copolymer (a1) has. For example, when the functional group is a hydroxyl group, an amino group or a substituted amino group, the group is preferably an isocyanate group or an epoxy group. When the functional group is an epoxy group, the group is an amino group, a carboxyl group or an aziridinyl group. Is preferred.

  In addition, the unsaturated group-containing compound (a2) preferably contains 1 to 5, more preferably 1 to 2, energy beam polymerizable carbon-carbon double bonds per molecule. Specific examples of such unsaturated group-containing compound (a2) include, for example, 2- (meth) acryloyloxyethyl isocyanate, meta-isopropenyl-α, α-dimethylbenzyl isocyanate, (meth) acryloyl isocyanate, allyl isocyanate. 1,1- (bis (meth) acryloyloxymethyl) ethyl isocyanate; an acryloyl monoisocyanate compound obtained by reaction of a diisocyanate compound or a polyisocyanate compound with hydroxyethyl (meth) acrylate; a diisocyanate compound or a polyisocyanate compound; An acryloyl monoisocyanate compound obtained by reaction of a polyol compound with hydroxyethyl (meth) acrylate; glycidyl (meth) acrylate; (meth) acrylate Examples include rilic acid, 2- (1-aziridinyl) ethyl (meth) acrylate, 2-vinyl-2-oxazoline, and 2-isopropenyl-2-oxazoline.

  The unsaturated group-containing compound (a2) is usually used in a ratio of 10 to 100 equivalents, preferably 20 to 95 equivalents, per 100 equivalents of the functional group-containing monomer of the acrylic copolymer (a1).

  In the reaction between the acrylic copolymer (a1) and the unsaturated group-containing compound (a2), depending on the combination of the group and the functional group, the reaction temperature, the pressure during the reaction, the solvent, the reaction time, the catalyst The presence / absence of a catalyst, the type of catalyst used, etc. can be selected as appropriate. As a result, the functional group present in the acrylic copolymer (a1) reacts with the group in the unsaturated group-containing compound (a2), and the unsaturated group is in the acrylic copolymer (a1). The energy beam curable polymer (A) is obtained.

  The weight average molecular weight of the energy beam curable polymer (a) is preferably 10,000 or more, more preferably 150,000 to 1,500,000, and further preferably 200,000 to 1,000,000. In addition, the weight average molecular weight (Mw) of the energy beam curable polymer (A) in this specification is a value in terms of standard polystyrene measured by a gel permeation chromatography method (GPC method).

Even when the energy ray-curable pressure-sensitive adhesive has a polymer having energy ray-curability as a main component, the energy ray-curable pressure-sensitive adhesive further contains an energy ray-curable monomer and / or oligomer (b). May be.
Any of the energy ray-curable monomers and oligomers can be used singly or in combination of two or more.

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

  Examples of the energy ray-curable monomer and / or oligomer (b) include monofunctional acrylic acid esters such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate; trimethylolpropane tri (meth) acrylate, Pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polyethylene Polyfunctional acrylic acid esters such as glycol di (meth) acrylate and dimethyloltricyclodecane di (meth) acrylate; polyester oligo (meth) acrylate, polyurethane oligo (meth) acrylate Rate, and the like.

  When the energy ray curable monomer and / or oligomer (b) is blended, the content of the energy ray curable monomer and / or oligomer (b) in the energy ray curable pressure-sensitive adhesive is 5 to 80% by mass. It is preferable and it is more preferable that it is 20-60 mass%.

  Here, when using ultraviolet rays as an energy ray for curing the energy ray-curable resin composition, it is preferable to add a photopolymerization initiator (c), and by using this photopolymerization initiator (c). The polymerization curing time and the amount of light irradiation can be reduced.

  Specific examples of the photopolymerization initiator (c) include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, benzoin dimethyl ketal, 2,4-diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, β-chloranthraquinone, (2,4 6-trimethylbenzyldiphenyl) phosphine oxide, 2-benzothiazole-N, N-diethyldithiocarbamate, oligo {2-hydroxy-2-methyl 1- [4- (1-propenyl) phenyl] propanone}, 2,2-dimethoxy-like. These may be used alone or in combination of two or more.

  The photopolymerization initiator (c) is an energy beam curable copolymer (a) 100 parts by mass (when the energy beam curable monomer and / or oligomer (b) is blended) (A) and energy ray-curable monomer and / or oligomer (b) in a total amount of 100 parts by mass), preferably 0.1 to 10 parts by mass, more preferably 0.5 to 6 parts by mass. Used in the amount of.

In the energy ray curable pressure-sensitive adhesive, other components may be appropriately blended in addition to the above components. As said other component, the polymer component or oligomer component (d) which does not have energy-beam sclerosis | hardenability, a crosslinking agent (e), etc. are mentioned, for example.
The said other component can be used individually by 1 type or in combination of 2 or more types.

  Examples of the polymer component or oligomer component (d) having no energy ray curability include polyacrylates, polyesters, polyurethanes, polycarbonates, polyolefins, and the like, and polymers having a weight average molecular weight (Mw) of 3000 to 2.5 million. Or an oligomer is preferable.

  As a crosslinking agent (e), the polyfunctional compound which has the reactivity with the functional group which an energy-beam curable copolymer (a) etc. have can be used. Examples of such polyfunctional compounds include isocyanate compounds, epoxy compounds, amine compounds, melamine compounds, aziridine compounds, hydrazine compounds, aldehyde compounds, oxazoline compounds, metal alkoxide compounds, metal chelate compounds, metal salts, ammonium salts. And reactive phenol resins.

  By blending these energy ray-curable polymer component or oligomer component (d) and crosslinking agent (e) in the energy ray-curable pressure-sensitive adhesive, the pressure-sensitive adhesive layer 42 has adhesiveness and peelability before curing. , Strength after curing, adhesion to other layers, storage stability and the like can be improved. The compounding quantity of these other components is not specifically limited, Preferably it is suitably determined in the range of 0-40 mass parts with respect to 100 mass parts of energy-beam curable copolymers (a).

  Next, the case where the energy ray-curable pressure-sensitive adhesive is mainly composed of a mixture of a polymer component having no energy ray curability and an energy ray-curable polyfunctional monomer and / or oligomer will be described below.

  As a polymer component which does not have energy ray curability, the component similar to the acrylic copolymer (a1) mentioned above can be used, for example. The content of the polymer component having no energy beam curability in the energy beam curable resin composition is preferably 20 to 99.9% by mass, and more preferably 30 to 80% by mass.

  As the energy ray-curable polyfunctional monomer and / or oligomer, the same one as the above-mentioned component (b) is selected.

  In the energy ray curable pressure-sensitive adhesive, the total amount of the energy ray curable polyfunctional monomer and oligomer is preferably 10 to 150 parts by mass with respect to 100 parts by mass of the polymer component, and preferably 25 to 100. More preferably, it is part by mass.

  Even when the energy ray curable pressure-sensitive adhesive is mainly composed of a mixture of a polymer component having no energy ray curable property and an energy ray curable polyfunctional monomer and / or oligomer, photopolymerization is started in the same manner as described above. An agent (c) and a crosslinking agent (e) can be appropriately blended.

  The thickness of the pressure-sensitive adhesive layer 42 is not particularly limited as long as it can function properly in each step in which the protective film forming sheet 3 is used. Specifically, the thickness of the pressure-sensitive adhesive layer 42 is preferably 1 to 50 μm, more preferably 2 to 30 μm, and further preferably 3 to 20 μm.

  As an adhesive which comprises the adhesive layer 5 for jig | tool, what has desired adhesive force and removability is preferable, for example, an acrylic adhesive, a rubber adhesive, a silicone adhesive, a urethane adhesive Polyester-based pressure-sensitive adhesives, polyvinyl ether-based pressure-sensitive adhesives, and the like can be used. Among these, as an adhesive constituting the adhesive layer 5 for jigs, the adhesiveness with a jig such as a ring frame is high, and the protective film forming sheet 3 is peeled off from the ring frame or the like in a dicing process or the like. An acrylic pressure-sensitive adhesive capable of effectively suppressing the above is preferred. In addition, the base material as a core material may intervene in the middle of the thickness direction of the adhesive layer 5 for jigs.

  The thickness of the jig pressure-sensitive adhesive layer 5 is preferably 5 to 200 μm, and more preferably 10 to 100 μm, from the viewpoint of adhesion to a jig such as a ring frame.

2. Method for Producing Protective Film Forming Sheet 3 The protective film forming sheet 3 is preferably prepared separately from a first laminate including the protective film forming film 1 and a second laminate including the adhesive sheet 4. Then, it can be manufactured by laminating the protective film-forming film 1 and the pressure-sensitive adhesive sheet 4 using the first laminated body and the second laminated body, but is not limited thereto. .

  In order to manufacture the first laminate, the protective film-forming film 1 is formed on the release surface of the first release sheet. Specifically, a coating agent for a protective film forming film containing a curable adhesive constituting the protective film forming film 1 and, if desired, further a solvent is prepared, and a roll coater, a knife coater, and a roll knife coater are prepared. Then, the protective film forming film 1 is formed by applying to the release surface of the first release sheet by a coating machine such as an air knife coater, die coater, bar coater, gravure coater, curtain coater, and drying. Next, the release surface of the second release sheet is superimposed on the exposed surface of the protective film-forming film 1 and pressure-bonded, and a laminate (first film) in which the protective film-forming film 1 is sandwiched between the two release sheets. A laminate is obtained.

  In this 1st laminated body, half cut may be given if desired, and the film 1 for protective film formation (and 2nd peeling sheet) may be made into a desired shape, for example, a circular shape. In this case, the excess part of the protective film-forming film 1 and the second release sheet produced by the half cut may be appropriately removed.

  On the other hand, in order to produce the second laminate, a coating agent for the pressure-sensitive adhesive layer further containing a pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 42 and, if desired, a solvent, on the release surface of the third release sheet. The pressure-sensitive adhesive layer 42 is formed by applying and drying. Then, the base material 41 is crimped | bonded to the exposed surface of the adhesive layer 42, and the laminated body (2nd laminated body) which consists of the adhesive sheet 4 which consists of the base material 41 and the adhesive layer 42, and a 3rd peeling sheet. obtain.

  Here, when the pressure-sensitive adhesive layer 42 is made of an energy ray-curable pressure-sensitive adhesive, the pressure-sensitive adhesive layer 42 may be irradiated with energy rays at this stage to cure the pressure-sensitive adhesive layer 42 or to protect it. The adhesive layer 42 may be cured after being laminated with the film forming film 1. Further, when the pressure-sensitive adhesive layer 42 is cured after being laminated with the protective film-forming film 1, the pressure-sensitive adhesive layer 42 may be cured before the dicing process, or the pressure-sensitive adhesive layer 42 may be cured after the dicing process. .

As energy rays, ultraviolet rays, electron beams, etc. are usually used. Irradiation of energy rays varies depending on the kind of energy rays, for example, in the case of ultraviolet rays, it is preferable that the light amount is 50~1000mJ / cm ^2, and more preferably 100 to 500 mJ / cm ^2. In the case of an electron beam, it is preferably about 10 to 1000 krad.

  When the first laminate and the second laminate are obtained as described above, the second release sheet in the first laminate is released and the third release sheet in the second laminate is released. Then, the protective film-forming film 1 exposed in the first laminate and the adhesive layer 42 of the adhesive sheet 4 exposed in the second laminate are overlapped and pressure-bonded. The pressure-sensitive adhesive sheet 4 may be half-cut if desired, and may have a desired shape, for example, a circle having a larger diameter than the protective film-forming film 1. In this case, an excess portion of the pressure-sensitive adhesive sheet 4 generated by the half cut may be removed as appropriate.

  In this way, the pressure-sensitive adhesive sheet 4 in which the pressure-sensitive adhesive layer 42 is laminated on the base material 41, the protective film-forming film 1 laminated on the pressure-sensitive adhesive layer 42 side of the pressure-sensitive adhesive sheet 4, and the protective film-forming film A protective film forming sheet 3 comprising a first release sheet laminated on the opposite side of the film 1 from the adhesive sheet 4 is obtained. Finally, after peeling off the first release sheet, a jig adhesive layer 5 is formed on the peripheral edge of the protective film-forming film 1 opposite to the adhesive sheet 4. The jig pressure-sensitive adhesive layer 5 can also be formed by the same method as the pressure-sensitive adhesive layer 42.

3. Method of Using Protective Film Forming Sheet 3 Using the protective film forming sheet 3 according to the present embodiment, as an example, a chip (processed product) on which a protective film is formed from a semiconductor wafer as a workpiece is subjected to a modified layer destruction. A method of manufacturing by a manufacturing method including a split process by the type tension split will be described below.

  As shown in FIG. 4, the protective film forming film 1 of the protective film forming sheet 3 is attached to the semiconductor wafer 6, and the jig adhesive layer 5 is attached to the ring frame 7. In sticking the protective film-forming film 1 to the semiconductor wafer 6, the protective film-forming film 1 may be heated to exhibit adhesiveness if desired.

Thereafter, the protective film-forming film 1 is cured to form a protective film.
As described above, the protective film is formed on the surface of the pressure-sensitive adhesive sheet 4 functioning as an extensible dicing sheet on the pressure-sensitive adhesive layer 42 side, and the semiconductor wafer 6 is formed on the surface of the protective film opposite to the surface on the pressure-sensitive adhesive layer 42 side. To obtain a stacked structure (in this specification, the stacked structure is also referred to as a “first stacked structure”). The first laminated structure shown in FIG. 4 further includes a jig pressure-sensitive adhesive layer 5 and a ring frame 7. When the protective film-forming film 1 is a thermosetting adhesive, the protective film may be formed by heating the protective film-forming film 1 at a predetermined temperature for an appropriate time. In addition, you may perform hardening of the film 1 for protective film formation after either of the laser printing and division process which are demonstrated below.

  If the 1st laminated structure provided with the semiconductor wafer 6 in which the protective film was formed as mentioned above was obtained, if desired, the protective film was irradiated with a laser beam through the adhesive sheet 4, and laser Perform printing. Thus, a protective film was formed on the workpiece using the protective film-forming sheet, and the surface of the workpiece on which the protective film was formed was irradiated with laser light to form a printed protective film. Work can be manufactured. Laser printing may be performed after the division processing described below.

  Next, the first laminated structure is installed in a split processing laser irradiation apparatus, and the position of the surface of the semiconductor wafer 6 covered with the protective film 1 is detected, and then the semiconductor wafer 6 is used by using the processing laser. A modified layer is formed inside. Then, a force (tensile force in the main surface direction) is applied to the semiconductor wafer 6 with a protective film by performing an expanding process for extending the pressure-sensitive adhesive sheet 4 functioning as a dicing sheet. As a result, the semiconductor wafer 6 with a protective film adhered to the adhesive sheet 4 is divided to obtain a chip having a protective film (chip with a protective film). Thereafter, a chip with a protective film is picked up from the adhesive sheet 4 using a pickup device.

  Here, laser irradiation for printing may be performed not on the semiconductor wafer 6 on which the protective film is formed but on the chip on which the protective film is formed. That is, a protective film is formed on a workpiece (semiconductor wafer 6) using a protective film forming sheet, and a workpiece (chip) formed by processing the workpiece (semiconductor wafer 6) on which the protective film is formed. ) And irradiating the surface of the workpiece (chip) on which the protective film is formed with a laser beam to produce a workpiece (chip) on which the printed protective film is formed. .

  Whether the adherend of the protective film according to an embodiment of the present invention is a workpiece (semiconductor wafer 6) or a workpiece (chip), the protective film has an average particle size of the filler contained therein of 0. Since the thickness is 2 μm or more, the light transmittance at a wavelength of 550 nm is 10% or less, and the appearance of the workpiece (semiconductor wafer 6) or workpiece (chip) as an adherend can be improved.

4). Other Embodiments of Protective Film Forming Sheet FIG. 3 is a cross-sectional view of a protective film forming sheet according to still another embodiment of the present invention. As shown in FIG. 3, the protective film forming sheet 3 </ b> A according to this embodiment includes a pressure-sensitive adhesive sheet 4 in which a pressure-sensitive adhesive layer 42 is laminated on one surface side of a base material 41, and a pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet 4. And a protective film forming film 1 laminated on the 42 side. The protective film-forming film 1 in the present embodiment is formed to be substantially the same as or slightly larger than the work in the surface direction and smaller than the pressure-sensitive adhesive sheet 4 in the surface direction. The part of the adhesive layer 42 where the protective film forming film 1 is not laminated can be attached to a jig such as a ring frame.

  The material and thickness of each member of the protective film forming sheet 3A according to the present embodiment are the same as the material and thickness of each member of the protective film forming sheet 3 described above. However, when the pressure-sensitive adhesive layer 42 is made of an energy ray-curable pressure-sensitive adhesive, the portion in contact with the protective film-forming film 1 in the pressure-sensitive adhesive layer 42 cures the energy ray-curable pressure-sensitive adhesive, and the other portions are It is preferable not to cure the energy ray curable adhesive. Thereby, while being able to make high the smoothness (gloss) of the protective film which hardened the film 1 for protective film formation, the adhesive force with respect to jigs, such as a ring frame, can be maintained high.

  In addition, the adhesive for jigs similar to the adhesive layer 5 for jigs in the above-mentioned protective film forming sheet 3 is provided on the peripheral edge of the adhesive layer 42 of the protective film forming sheet 3A on the side opposite to the base material 41. An agent layer may be provided separately.

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

  For example, a release sheet may be laminated on the side opposite to the adhesive sheet 4 in the protective film forming film 1 of the protective film forming sheets 3 and 3A.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to the following examples.

<Manufacture of protective film forming sheet>
[Example 1]
The following components were mixed at a blending ratio (in terms of solid content) shown in Table 1, and diluted with methyl ethyl ketone so that the solid content concentration was 61% by mass to prepare a coating agent for a film for forming a protective film.
(A) Polymer component: acrylic polymer (weight average molecular weight) obtained by copolymerizing 10 parts by mass of n-butyl acrylate, 70 parts by mass of methyl acrylate, 5 parts by mass of glycidyl methacrylate, and 15 parts by mass of 2-hydroxyethyl acrylate : 400,000, glass transition temperature: -1 ° C)
(B-1) Bisphenol A type epoxy resin (“jER828” manufactured by Mitsubishi Chemical Corporation, liquid at 23 ° C./1 atm, molecular weight 370, softening point 93 ° C., epoxy equivalent 183 to 194 g / eq)
(B-2) Bisphenol A type epoxy resin (“jER1055” manufactured by Mitsubishi Chemical Corporation, solid at 23 ° C./1 atm, molecular weight 1600, epoxy equivalent 800-900 g / eq)
(B-3) Dicyclopentadiene type epoxy resin (“Epiclon HP-7200HH” manufactured by DIC, solid at 23 ° C./1 atm, softening point 88-98 ° C., epoxy equivalent 255-260 g / eq)
(C-1) Thermally active latent epoxy resin curing agent (Dicyandiamide, “ADEKA HARDNER EH-3636AS” manufactured by ADEKA, active hydrogen content 21 g / eq)
(C-2) Thermally active latent epoxy resin curing agent (dicyandiamide, “DICY7” manufactured by Mitsubishi Chemical Corporation)
(D) Curing accelerator: 2-phenyl-4,5-dihydroxymethylimidazole (“Curesol 2PHZ” manufactured by Shikoku Kasei Kogyo Co., Ltd.)
(E-1) Silica filler (manufactured by Admatechs “YA050CMJA”, average particle size 0.05 μm)
(E-2) Silica filler (manufactured by Admatechs “SC2050MA”, average particle size 0.5 μm)
(E-3) Silica filler (manufactured by Admatechs “YC100CMLA”, average particle size 0.1 μm)
(E-4) Silica filler (Admutex's "SC1050" modified with vinyl group surface by silane coupling agent (Shin-Etsu Chemical Co., Ltd.'s "KBM1003"), average particle size 0.3 µm)
(F) Silane coupling agent (“KBM403” manufactured by Shin-Etsu Chemical Co., Ltd.)
(G-1) Colorant (blue pigment): A pigment obtained by using a phthalocyanine blue pigment (Pigment Blue 15: 3) in an amount such that the mass ratio of the pigment component to the styrene-acrylic resin is 1/3.
(G-2) Colorant (yellow pigment): A pigment obtained by using an isoindolinone-based yellow pigment (Pigment Yellow 139) in an amount such that the mass ratio of the pigment component to the styrene-acrylic resin is 1/3.
(G-3) Colorant (red pigment): A pigment obtained by using a diketopyrrolopyrrole red pigment (Pigment Red 264) in an amount such that the mass ratio of the pigment component to the styrene-acrylic resin is 1/3.
(H) Colorant: Carbon black (“MA600B” manufactured by Mitsubishi Chemical Corporation, average particle size 28 nm)

  Here, the weight average molecular weight (Mw) of the polymer component (A) is a weight average molecular weight in terms of standard polystyrene measured (GPC measurement) by gel permeation chromatography (GPC) under the following conditions.

(GPC measurement conditions)
Column: TSKgel GMHXL (2), TSKgel 2000HXL connected in this order Solvent: Tetrahydrofuran Measurement temperature: 40 ° C
・ Flow rate: 1 ml / min ・ Detector: differential refractometer ・ Standard sample: polystyrene

  A first release sheet ("SP-PET 382150" manufactured by Lintec Co., Ltd., thickness 38 μm) having a silicone release agent layer formed on one side of a polyethylene terephthalate (PET) film, and a silicone release on one side of the PET film A second release sheet (“SP-PET 381031” manufactured by Lintec Corporation, thickness 38 μm) formed with an agent layer was prepared.

  After applying the above-mentioned coating agent for forming a protective film on the release surface of the first release sheet with a knife coater so that the final protective film-forming film has a thickness of 23 μm. Then, the film was dried at 120 ° C. for 2 minutes using an oven to form a protective film-forming film. Next, the release surface of the second release sheet is laminated on the protective film forming film and bonded together, and then the first release sheet (release sheet 21 in FIG. 1) and the protective film forming film (protective film in FIG. 1). A protective film-forming sheet comprising a forming film 1) (thickness: 25 μm) and a second release sheet was obtained.

[Examples 2-3, Reference Examples 1-7]
A protective film-forming sheet was produced in the same manner as in Example 1 except that the types and blending amounts of the components constituting the protective film-forming film were changed as shown in Table 1.

<Evaluation of protective film forming sheet>
(Light transmittance)
The second release sheet is peeled from the protective film-forming sheets obtained in the above examples and reference examples, and heated in an oven at 130 ° C. for 2 hours in an oven to thermally cure the protective film-forming film. Thus, a protective film was obtained. Thereafter, the first release sheet was peeled off.

  Using a spectrophotometer (“UV-VIS-NIR SPECTROTOPOMETER UV-3600” manufactured by SHIMADZU), the light transmittance of the protective film is measured, and the light transmittance (%) at wavelengths of 550 nm, 1064 nm and 1250 nm is extracted. did. For the measurement, the attached large sample chamber MPC-3100 was used, and the measurement was performed without using the built-in integrating sphere. The results are shown in Table 1.

(appearance)
The second release sheet is peeled off from the protective film-forming sheets obtained in the above examples and reference examples, and the protective film-forming film is applied to the polishing surface of a silicon wafer (# 200 polishing, diameter 200 mm, thickness 280 μm). Affixed. A tape mounter (“Adwill RAD-3600” manufactured by Lintec Corporation) was used for pasting. After peeling the first release sheet from the protective film-forming film, the silicon wafer and the protective film-forming film are heated in an oven at 130 ° C. for 2 hours in an oven to thermally cure the protective film-forming film. Thus, a protective film was obtained. The obtained silicon wafer with a protective film was visually observed from the protective film side, and whether or not the polished surface of the silicon wafer was visually recognized through the protective film was confirmed according to the following criteria, and the appearance was evaluated. The results are shown in Table 1.
A: The polished surface is not visually recognized at all.
B: The polished surface is slightly visually recognized.
C: The polished surface is clearly visually recognized.

(Measurement of 60 degree specular gloss)
The second release sheet is peeled off from the protective film-forming sheets obtained in the above examples and reference examples, and the protective film-forming film is applied to the polishing surface of a silicon wafer (# 200 polishing, diameter 200 mm, thickness 280 μm). Affixed. A tape mounter (“Adwill RAD-3600” manufactured by Lintec Corporation) was used for pasting. After peeling the first release sheet from the protective film-forming film, the silicon wafer and the protective film-forming film are heated in an oven at 130 ° C. for 2 hours in an oven to thermally cure the protective film-forming film. Thus, a protective film was obtained. Using the gloss meter “VG 2000” manufactured by Nippon Denshoku Industries Co., Ltd., the surface on the protective film side of the obtained silicon wafer with a protective film, according to JIS Z8741: 1997 (ISO 2813: 1994), a 60-degree specular gloss ( Gs (60 °, unit:%) was measured. The results are shown in Table 1.

(Print visibility)
Using the green laser marker ("MD-S9910A" manufactured by Keyence Corporation), laser printing was performed on the silicon wafer with a protective film obtained at the time of measuring the 60-degree specular gloss.
Wavelength: 532nm
Output: 3.0W
Frequency: 60kHz
Scanning speed: 500mm / s
Print character: ABCD
Character size: 300 μm (height) x 250 μm (width)
Character spacing: 50 μm

Next, the obtained prints were observed at a magnification of 100 times using a digital microscope (“VHS-1000” manufactured by Keyence Corporation), and evaluated in the following three stages (A to C). The results are shown in Table 1. Further, the image data of the printed protective film is shown in FIG. 5 for Example 1, FIG. 6 for Reference Example 1, and FIG. 7 for Reference Example 3.
A: The printing is easily recognized and the printing looks clear.
B: Recognition of printing is easy.
C: It is difficult to recognize printing.

  As is apparent from Table 1, the protective film-forming films of Examples 1 to 3 in which the average particle diameter of the filler contained is 0.3 μm or more and the light transmittance at a wavelength of 550 nm is 8% or less are formed from this. The protective film thus made prevents the polished surface of the silicon wafer from being seen at all, and the appearance of the wafer with the protective film is remarkably improved. The protective film-forming films of these examples are different from the protective film-forming films of Reference Examples 5 to 6, for example, even if they contain no pigment or have a low pigment content, they transmit light with a wavelength of 550 nm. The rate was low enough.

  The film for forming a protective film and the sheet for forming a protective film according to the present invention can be used for manufacturing a workpiece such as a semiconductor wafer having a protective film formed on the back surface and a processed product (chip or the like).

DESCRIPTION OF SYMBOLS 1 ... Film for protective film formation 2 ... Sheet for protective film formation 21 ... Release sheet 3, 3A ... Sheet for protective film formation 4 ... Adhesive sheet 41 ... Base material 42 ... -Adhesive layer 5 ... Adhesive layer for jigs 6 ... Semiconductor wafer 7 ... Ring frame

Claims (11)

A protective film-forming film containing a filler,
The film for protective film formation whose average particle diameter of the said filler is 0.2 micrometer or more, and the light transmittance of wavelength 550nm is 10% or less.   The film for forming a protective film according to claim 1, wherein the light transmittance at a wavelength of 1250 nm is 40% or more.   The protective film-forming film according to claim 1 or 2, wherein the content of the colorant in the protective film-forming film is 3% by mass or less.   The film for protective film formation as described in any one of Claims 1-3 in which the said film for protective film formation contains an organic pigment.   The protective film-forming film according to claim 1, wherein the protective film-forming film contains an epoxy resin.   The protective film-forming film according to claim 5, wherein the epoxy resin contains at least a liquid epoxy resin at 23 ° C. and 1 atm.   The epoxy resin consists only of the liquid epoxy resin, or the epoxy resin contains the liquid epoxy resin and a solid epoxy resin at 23 ° C. and 1 atm, and the liquid epoxy resin and the solid epoxy resin The film for protective film formation of Claim 6 whose ratio of content of the said liquid epoxy resin with respect to the total content of an epoxy resin is 25 to 100 mass%.   The protective film formation as described in any one of Claims 1-7 laminated | stacked on the adhesive layer side of the adhesive sheet by which the adhesive layer is laminated | stacked on the one surface side of a base material, and the said adhesive sheet. And a protective film-forming sheet.   Using the protective film-forming film according to any one of claims 1 to 7 or the protective film-forming sheet according to claim 8, the workpiece or a workpiece formed by dividing the workpiece is protected. A method for manufacturing a workpiece or a workpiece to form a film.   Irradiating laser light in the infrared region so that the division processing is focused on a focal point set in the workpiece, a modified layer is formed inside the workpiece, and the workpiece having the modified layer formed thereon The method of manufacturing a workpiece or a workpiece according to claim 9, wherein the workpiece or workpiece is processed by applying a force and dividing the workpiece on which the modified layer is formed to obtain a plurality of pieces as a workpiece.   The work or workpiece manufacturing method according to claim 9 or 10, wherein the workpiece is a semiconductor wafer and the workpiece is a semiconductor chip.