JP6006936B2 - Dicing sheet with protective film forming layer and chip manufacturing method - Google Patents

Description

  The present invention relates to a dicing sheet with a protective film forming layer that can form a protective film on the back surface of the chip and can improve the manufacturing efficiency of the chip. Moreover, this invention relates to the manufacturing method of the chip | tip using the dicing sheet with a protective film formation layer.

  2. Description of the Related Art In recent years, semiconductor devices have been manufactured using a so-called “face down” mounting method. In the face-down method, a semiconductor chip (hereinafter simply referred to as “chip”) having electrodes such as bumps on a circuit surface is used, and the electrodes are bonded to a substrate. For this reason, the surface (chip back surface) opposite to the circuit surface of the chip may be exposed.

  The exposed back surface of the chip may be protected by an organic film. Conventionally, a chip having a protective film made of an organic film is obtained by applying a liquid resin to the back surface of a wafer by spin coating, drying and curing, and cutting the protective film together with the wafer. However, since the thickness accuracy of the protective film formed in this way is not sufficient, the product yield may be lowered.

  In order to solve the above problems, a chip protective film having a release sheet and a protective film forming layer formed on the release sheet and composed of an energy ray-curable component and a binder polymer component is disclosed (Patent Document). 1).

  Furthermore, at the present time when semiconductor chips are becoming thinner and denser, even when exposed to severe temperature conditions, a semiconductor device mounted with a chip with a protective film has higher reliability. Is required.

JP 2009-138026 A

  According to the study by the present inventors, the chip protective film described in Patent Document 1 may shrink when the protective film forming layer is cured, which may cause a problem that the semiconductor wafer is warped. In particular, the above problem is remarkable in an extremely thin semiconductor wafer. If the semiconductor wafer is warped, the wafer may be damaged or the marking (printing) accuracy on the protective film may be reduced. Moreover, in the chip protective film described in Patent Document 1, when manufacturing a chip with a protective film, it is necessary to affix the wafer with a protective film to a dicing sheet and dice the wafer, and the manufacturing process is complicated. . If a release sheet having a good balance between shape retention and extensibility is used as the release sheet, there is a possibility that the above problems can be solved at the same time. However, when such a release sheet is used, the process conditions are limited, for example, the curing conditions of the protective film forming layer are limited to a narrow range, and as a result, the protective film forming layer that can be used is also limited. In addition, when the protective film forming layer is cured or after the wafer is diced, it is not possible to completely prevent the release sheet from expanding and contracting, the distance between chips is narrowed, chip alignment is impaired, and chips may contact each other. is there.

  The present invention has been made in view of the above circumstances. That is, an object of the present invention is to provide a dicing sheet with a protective film forming layer that can easily manufacture a semiconductor chip having a protective film with high uniformity and excellent printing accuracy, and that has excellent expandability.

The present invention includes the following gist.
(1) having a protective film forming layer on the inner peripheral portion of the heat resistant film surface of the laminated sheet having the base film and the heat resistant film;
Having an adhesive layer on the outer peripheral surface of the heat-resistant film,
A dicing sheet with a protective film forming layer, wherein the heat-resistant film has a melting point exceeding 130 ° C. or has no melting point, and the heat shrinkage rate of the heat-resistant film when heated at 130 ° C. for 2 hours is −1 to + 1%.

(2) The dicing sheet with a protective film forming layer according to (1), wherein a groove that surrounds the protective film forming layer and completely cuts the heat resistant film in the thickness direction is formed.

(3) The base film has a melting point of more than 130 ° C. or no melting point, the base film has a thermal shrinkage of −5 to + 5% when heated at 130 ° C. for 2 hours, and the base film has an MD direction. The dicing sheet with a protective film forming layer according to (1) or (2), wherein the elongation at break in the tensile measurement is 100% or more and the 25% stress is 100 MPa or less in both the CD direction and the CD direction.

(4) The dicing sheet with a protective film forming layer according to any one of (1) to (3), wherein the total light transmittance of the laminated sheet at wavelengths of 532 nm and 1064 nm is 70% or more.

(5) The dicing sheet with a protective film forming layer according to any one of (1) to (4), wherein the protective film forming layer contains a binder polymer component and a curable component.

(6) The protective film forming layer contains a colorant,
The dicing sheet with a protective film forming layer according to any one of (1) to (5), wherein the total light transmittance of the protective film forming layer at a wavelength of 300 to 1200 nm is 20% or less.

(7) The protective film forming layer of the dicing sheet with the protective film forming layer according to any one of (1) to (6) above is affixed to a workpiece, and the following steps are performed as (1), (2), ( Chip manufacturing method performed in the order of 3):
Step (1): The protective film forming layer is cured to obtain a protective film.
Step (2): dicing the workpiece and the protective film forming layer or the protective film,
Step (3): peeling off the protective film and the heat-resistant film.

(8) The chip manufacturing method according to (7), wherein the following step (4) is performed in any step after the step (1):
Step (4): Laser printing on the protective film.

(9) The method for manufacturing a chip according to (7) or (8), wherein the heat-resistant film is fully cut in the step ( 2 ).

  When forming the protective film on the back surface of the semiconductor chip, by using the dicing sheet with the protective film forming layer according to the present invention, a protective film having high uniformity and excellent printing accuracy can be easily formed on the back surface of the semiconductor chip. it can.

Sectional drawing of the dicing sheet with a protective film formation layer concerning this invention is shown.

  Hereinafter, the present invention will be described more specifically, including its best mode. As shown in FIG. 1, the dicing sheet 10 with a protective film forming layer according to the present invention has a protective film forming layer 4 on the inner peripheral portion of the surface of the heat resistant film 2 of the laminated sheet having the base film 1 and the heat resistant film 2. And has an adhesive layer 3 on the outer peripheral surface of the heat-resistant film. The base film and the heat-resistant film are substantially the same size, and an annular pressure-sensitive adhesive layer is formed on the outer peripheral surface of the heat-resistant film, and the pressure-sensitive adhesive layer 3 is bonded to the ring frame 6 as shown in the figure. Used for. Moreover, it is preferable that the heat resistant film 2 has a groove 5 that surrounds the protective film forming layer 4 and completely cuts the heat resistant film 2 in the thickness direction. In FIG. 1, the groove 5 is at the same position as the edge of the protective film forming layer and is provided along the outer periphery of the protective film forming layer. However, the groove 5 is formed so as to surround the protective film forming layer. For example, it may not be along the outer periphery of the protective film forming layer 4.

(Base film 1)
The base film 1 in the present invention preferably has appropriate heat resistance and extensibility. Specifically, the melting point of the base film preferably exceeds 130 ° C. or does not have a melting point. The thermal contraction rate of the base film when heated at 130 ° C. for 2 hours is preferably −5 to + 5%. If the melting point of the base film is 130 ° C. or lower or the thermal shrinkage rate is outside the above range, the base film is melted when the protective film forming layer is cured, and it becomes difficult to maintain the shape of the base film. There is a fear. In addition, the base film may be fused with peripheral devices in the semiconductor chip manufacturing process. The thermal contraction rate is an index indicating the ease of thermal deformation of the base film. When a dicing sheet with a protective film forming layer is formed from a base film having a thermal shrinkage rate of less than −5% or more than + 5%, and the wafer is held and thermally cured, the weight of the wafer is applied to the wafer. The non-corresponding peripheral part (base film on the outer peripheral part of the pressure-sensitive adhesive sheet) is not contracted but rather stretched, and the dicing sheet with protective film forming layer tends to be loosened. As a result, the subsequent dicing process may be difficult, and it may be difficult to pick up (pick up) the chip after dicing from the dicing sheet with the protective film forming layer. The term “base film does not have a melting point” means that the base film undergoes thermal decomposition before exhibiting a melting point in thermal analysis.

  Moreover, any of MD direction (direction parallel to the direction which conveys a film at the time of film-forming a film long) and CD direction (direction orthogonal to MD direction on the same surface of a film) of a base film However, it is preferable that the elongation at break in the tensile measurement is 100% or more and the 25% stress of the base film is 100 MPa or less. When the dicing sheet with a protective film forming layer of the present invention is used, if the groove is provided in the heat-resistant film or if dicing is performed so that the heat-resistant film is completely cut, the base film is heat-resistant in the expanding step. The film can be stretched without being constrained by the film. If the elongation at break is less than 100% or the 25% stress exceeds 100 MPa, the expandability is inferior, which may cause pickup failure or chip damage due to contact between adjacent chips during pickup.

  The melting point of the base film is more preferably 140 ° C. or higher or no melting point, and more preferably 200 ° C. or higher or no melting point. Moreover, it is more preferable that the thermal contraction rate of the base film when heated at 130 ° C. for 2 hours is −4 to + 4%. By setting the melting point and the heat shrinkage rate of the base film within the above ranges, the base film is excellent in heat resistance, and the shape retention of the base film when the above protective film forming layer is cured is kept good. . In addition, the thermal contraction rate of the base film at the time of heating at 130 ° C. for 2 hours is obtained from the area of the base film before and after the base film is put in an environment at 130 ° C. by the following formula.

  Thermal shrinkage (%) = {(Area of base film before input) − (Area of base film after input)} / Area of base film before input × 100

  The 25% stress of the base film can be obtained by dividing the force when the base film is stretched by 25% by the cross-sectional area of the film.

  Further, the elongation at break in the MD direction and CD direction of the base film is more preferably 120% or more, and more preferably 250% or more. The 25% stress of the base film is more preferably 80 MPa or less, and more preferably 70 Ma or less. By making the breaking elongation and 25% stress of the base film within the above ranges, good expandability is exhibited, and pick-up failure and chip breakage due to contact between adjacent chips during pick-up can be suppressed.

  Examples of the base film include a polypropylene film, a polybutylene terephthalate film, an acrylic resin film, and a heat resistant polyurethane film. In addition, these cross-linked films and modified films by radiation and discharge can also be used. The base film may be a laminate of the films as long as the physical properties are satisfied.

  The thickness of a base film is not specifically limited, Preferably it is 30-300 micrometers, More preferably, it is 50-200 micrometers. By making the thickness of the base film within the above range, it has sufficient expandability even after cutting by dicing. Moreover, since the dicing sheet with a protective film forming layer has sufficient flexibility, it exhibits good adhesiveness to a workpiece (for example, a semiconductor wafer).

If the base film is not completely cut in the thickness direction at the portion corresponding to the groove of the heat-resistant film 2 to be described later, the base film may be cut to a predetermined depth together with the groove, or not cut. Also good. When cut, it is preferable that the cut portion has a thickness that remains without being cut to such an extent that it does not break during expansion, and specifically, the thickness is preferably about 30 μm or more.
(Heat resistant film 2)
The heat resistant film 2 is formed on one side of the base film 1. The base film 1 and the heat resistant film may be directly laminated by extrusion molding or heat sealing, or may be laminated via an adhesive layer or a strong pressure-sensitive adhesive layer. Under the present circumstances, in order to improve adhesiveness with a heat resistant film or an adhesive bond layer, the surface in which a heat resistant film of a base film is provided may be corona-treated, and the primer layer may be formed. .

The heat-resistant film 2 in the present invention has heat resistance enough to maintain its shape even in a high-temperature environment. Specifically, the heat-resistant film has a melting point of more than 130 ° C. or no melting point, and further 130 ° C. The heat shrinkage ratio of the heat-resistant film during heating for 2 hours is −1 to + 1%. If the melting point of the heat-resistant film is 130 ° C. or lower or the heat shrinkage rate is out of the above range, the heat-resistant film melts when the protective film forming layer is cured, and it becomes difficult to maintain the shape of the heat-resistant film. There is a risk that the process cannot be performed. In addition, the heat-resistant film may be fused with peripheral devices in the semiconductor chip manufacturing process. Furthermore, the printing accuracy on the protective film may decrease due to the deformation of the protective film forming layer caused by melting of the heat resistant film. The thermal shrinkage rate is an index indicating the ease of thermal deformation of the heat resistant film. When a dicing sheet with a protective film forming layer was constituted only from a heat-resistant film having a thermal shrinkage rate of less than -1% or more than + 1%, and the wafer was held and thermally cured, it was caused by the shrinkage of the heat-resistant film. Residual stress may be released in a later dicing process, and the distance between chips may be reduced. Such narrowing of the chip interval may deteriorate chip alignment or cause chipping due to contact between adjacent chips. When the heat shrinkage rate of the heat-resistant film is −1 to + 1% , such a narrowing of the chip interval can be prevented.

  The melting point of the heat-resistant film is more preferably 140 ° C. or higher, or has no melting point, particularly preferably the melting point is 200 ° C. or higher, or has no melting point. By setting the melting point and heat shrinkability of the heat-resistant film within the above ranges, the heat-resistant film is excellent in heat resistance, and the shape-retaining property of the heat-resistant film when the protective film-forming layer is cured is kept better. It is easy to obtain the effect of preventing narrowing of the chip interval. In addition, the heat shrinkage rate of the heat resistant film when heated at 130 ° C. for 2 hours is obtained from the area of the heat resistant film before and after the heat resistant film is put in an environment of 130 ° C. by the following formula.

Heat shrinkage (%) = {(area of the heat-resistant film predose) - (area of the heat-resistant film after on)} / charged surface product × 100 before the heat resistant film

  Examples of heat-resistant films include polyester films, polycarbonate films, polyphenylene sulfide films, cycloolefin resin films, polyimide resin films, films obtained by casting and curing UV curable resins, and laminates of two or more of these. Can do. The cycloolefin resin film or the polyimide resin film may be uniaxially stretched or biaxially stretched. The heat resistant film is not particularly limited as long as the physical properties are satisfied. The heat-resistant film is preferably peeled on one side (the surface on which the protective film forming layer is formed). Specifically, the entire surface of the heat-resistant film or the inner periphery of the heat-resistant film (the part on which the protective film-forming layer is formed) Is preferably peel-treated.

  As the release agent used for the release treatment, alkyd, silicone, fluorine, unsaturated polyester, polyolefin, wax, and the like are used. In particular, alkyd, silicone, and fluorine release agents are heat resistant. This is preferable.

  In order to release the surface of the heat-resistant film using the above release agent, the release agent can be applied directly with a gravure coater, Mayer bar coater, air knife coater, roll coater, etc. without solvent, or with solvent dilution or emulsion. Then, the laminate may be formed by room temperature or heating or electron beam curing, wet lamination, dry lamination, hot melt lamination, melt extrusion lamination, coextrusion processing, or the like. By peeling the surface of the heat-resistant film on the protective film forming layer side, peeling between the protective film-forming layer and the heat-resistant film is facilitated in a later step.

  When a polyolefin-based film such as a polypropylene film is used as the heat-resistant film, the protective film-forming layer may be peeled from the heat-resistant film without performing a peeling treatment depending on the characteristics of the film. In such a case, a heat-resistant film that has not been peeled may be used.

  The thickness of a heat-resistant film is not specifically limited, Preferably it is 30-300 micrometers, More preferably, it is 50-200 micrometers.

  When the work and the protective film are cut, the heat-resistant film 2 is completely cut, so that the dicing sheet of the present invention can be expanded after dicing, and the chip can be easily picked up. In order to facilitate expansion, it is preferable to previously form a groove 5 that surrounds the protective film forming layer 4 and completely cuts the heat-resistant film 2 in the thickness direction.

  The groove 5 may have any planar shape as long as it surrounds the protective film forming layer. However, in order to evenly convey the expansion of the expand to the work on which the individual protective film is formed, the protective film is formed. It is preferably similar to the forming layer. When the workpiece is a semiconductor wafer, since the semiconductor wafer is usually circular, the planar shape of the groove is preferably circular. The dicing sheet with a protective film forming layer of the present invention has an adhesive layer 3 provided on the outer peripheral surface for the purpose of adhering to the ring frame, and the groove is formed on the outer periphery of the protective film forming layer and the ring frame to be bonded. It is preferably formed between the inner circumferences (including the end). In addition, since the expansion is usually performed by pressing a cylindrical device against the dicing sheet, there may be an extra portion of about 10 to 100 mm for pressing the cylindrical device between the inner periphery of the ring frame and the groove. preferable. The groove and the protective film forming layer may have the same shape. That is, the groove may be provided along the outer periphery of the protective film forming layer. With such a configuration, it becomes easy to form grooves in the heat resistant film at the same time when the protective film forming layer is cut into a predetermined shape after the protective film forming layer is provided on the heat resistant film.

  The groove may not be continuous on the outer periphery thereof. For example, groove forming portions and non-forming portions may exist alternately like perforations. When the groove is continuous on the entire outer periphery, the base film may be stretched by the weight of the work at the outer periphery of the groove when the protective film forming layer is applied to the work and the heat curing process is performed. . By having the non-grooved portion of the groove, the base film is secured by the heat-resistant film of the non-grooved portion, and the base film can be prevented from stretching. As a result, it is possible to prevent the dicing sheet with the protective film forming layer from being deformed due to the stretching of the base film, and subsequent processes such as conveyance and dicing become difficult. In the expanding step, the expansion can be performed by designing the non-grooved portion of the groove so as to be easily broken by the tension of the expanding.

(Adhesive layer 3)
The pressure-sensitive adhesive layer 3 in the present invention can be formed of conventionally known various pressure-sensitive adhesives. Such an adhesive is not limited at all, but an adhesive such as rubber-based, acrylic-based, silicone-based, or polyvinyl ether is used. In addition, an energy ray curable adhesive, a heat-foaming adhesive, or a water swelling adhesive can be used. As the energy ray curable (ultraviolet ray curable, electron beam curable) pressure-sensitive adhesive, it is particularly preferable to use an ultraviolet curable pressure-sensitive adhesive.

  The pressure-sensitive adhesive layer is formed on the outer peripheral surface of the heat-resistant film. When manufacturing a chip to be described later, the pressure-sensitive adhesive layer is attached to the ring frame 6 at the outer peripheral portion of the heat-resistant film, and the ring frame after the curing process of the protective film forming layer When removing from the layer, glue residue may occur on the ring frame. Further, in the curing step of the protective film forming layer, the pressure-sensitive adhesive layer is exposed to a high temperature and softens, and adhesive residue is likely to occur. Therefore, among the above-mentioned pressure-sensitive adhesives, acrylic and silicone pressure-sensitive adhesives are preferable from the viewpoint of preventing adhesive residue on the ring frame and imparting heat resistance to the pressure-sensitive adhesive layer. When the entire surface of the heat-resistant film is peeled using a silicone-based release agent, a silicone-based pressure-sensitive adhesive is preferably used from the viewpoint of adhesion between the heat-resistant film and the pressure-sensitive adhesive layer.

  Further, the adhesive strength of the pressure-sensitive adhesive layer applied to the ring frame (adhesive strength to the SUS plate after being applied and heated at 130 ° C. for 2 hours) is preferably 15 N / 25 mm or less, more preferably 10 N / 25 mm or less, particularly preferably 5 N / 25 mm or less. By setting the adhesive strength of the pressure-sensitive adhesive layer within the above range, the adhesiveness to the ring frame is excellent, and adhesive residue on the ring frame can be prevented.

  Although the thickness of an adhesive layer is not specifically limited, Preferably it is 1-100 micrometers, More preferably, it is 3-80 micrometers, Most preferably, it is 5-50 micrometers.

The pressure-sensitive adhesive layer may be a double-sided tape provided with a pressure-sensitive adhesive layer on both sides of the core material film. The double-sided tape has a configuration of pressure-sensitive adhesive layer / core film / pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer in the double-sided tape is not particularly limited, and the above-mentioned pressure-sensitive adhesive can be used. In this case, as an adhesive layer which is located closest to the heat-resistant film, and silicone-based adhesive, from the viewpoint of adhesion between the heat-resistant film and the pressure-sensitive adhesive layer. Moreover, it is preferable that a core material film has heat resistance, and it is preferable to use a film with melting | fusing point of 120 degreeC or more as a core material film. When a film having a melting point of less than 120 ° C. is used as the core material film, the core material film may be melted and unable to maintain its shape or may be fused with peripheral devices during the heat curing of the protective film forming layer. is there. As the core material film, for example, a polyester film, a polypropylene film, a polycarbonate film, a polyimide film, a fluororesin film, a liquid crystal polymer film and the like are preferably used.

(Protective film forming layer 4)
The protective film formation layer 4 in this invention is not specifically limited, For example, a thermosetting, thermoplastic, and radiation curable protective film formation layer can be used. Among these, the heat-resistant film according to the present invention has heat resistance, and the effect of suppressing the occurrence of residual stress during thermosetting is preferably exerted. Is preferred.

  The protective film-forming layer preferably contains a binder polymer component (A) and a curable component (B).

(A) Binder polymer component The binder polymer component (A) is used for imparting sufficient adhesion and film forming property (sheet processability) to the protective film forming layer. As the binder polymer component (A), conventionally known acrylic polymers, polyester resins, urethane resins, acrylic urethane resins, silicone resins, rubber-based polymers, and the like can be used.

  The weight average molecular weight (Mw) of the binder polymer component (A) is preferably 10,000 to 2,000,000, and more preferably 100,000 to 1,200,000. If the weight average molecular weight of the binder polymer component (A) is too low, the adhesive force between the protective film-forming layer and the heat-resistant film is increased, and transfer failure of the protective film-forming layer may occur. Adhesiveness may decrease and transfer to a chip or the like may not be possible, or the protective film may be peeled off from the chip or the like after transfer.

  An acrylic polymer is preferably used as the binder polymer component (A). The glass transition temperature (Tg) of the acrylic polymer is preferably -60 to 50 ° C, more preferably -50 to 40 ° C, and particularly preferably -40 to 30 ° C. If the glass transition temperature of the acrylic polymer is too low, the peeling force between the protective film-forming layer and the heat-resistant film may increase, resulting in transfer failure of the protective film-forming layer, and if it is too high, the adhesion of the protective film-forming layer will be reduced. However, the transfer to the chip or the like may be impossible, or the protective film may be peeled off from the chip or the like after the transfer.

  Examples of the monomer constituting the acrylic polymer include a (meth) acrylic acid ester monomer or a derivative thereof. For example, alkyl (meth) acrylates having 1 to 18 carbon atoms in the alkyl group, specifically methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl Examples include (meth) acrylate. In addition, (meth) acrylate having a cyclic skeleton, specifically cyclohexyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, Examples include dicyclopentenyloxyethyl (meth) acrylate and imide (meth) acrylate. Furthermore, examples of the monomer having a functional group include hydroxymethyl (meth) acrylate having a hydroxyl group, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and the like; in addition, glycidyl (meth) having an epoxy group. An acrylate etc. are mentioned. As the acrylic polymer, an acrylic polymer containing a monomer having a hydroxyl group is preferable because of its good compatibility with the curable component (B) described later. The acrylic polymer may be copolymerized with acrylic acid, methacrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, or the like.

  Furthermore, you may mix | blend the thermoplastic resin for maintaining the flexibility of the protective film after hardening as a binder polymer component (A). Such a thermoplastic resin preferably has a weight average molecular weight of 1,000 to 100,000, more preferably 3,000 to 80,000. The glass transition temperature of the thermoplastic resin is preferably -30 to 120 ° C, more preferably -20 to 120 ° C. Examples of the thermoplastic resin include polyester resin, urethane resin, phenoxy resin, polybutene, polybutadiene, and polystyrene. These thermoplastic resins can be used individually by 1 type or in mixture of 2 or more types. By containing the above thermoplastic resin, the protective film forming layer follows the transfer surface of the protective film forming layer, and generation of voids or the like can be suppressed.

(B) Curable component The curable component (B) is a thermosetting component and / or an energy beam curable component.

  As the thermosetting component, a thermosetting resin and a thermosetting agent are used. As the thermosetting resin, for example, an epoxy resin is preferable.

  A conventionally well-known epoxy resin can be used as an epoxy resin. Specific examples of epoxy resins include polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and hydrogenated products thereof, orthocresol novolac epoxy resins, dicyclopentadiene type epoxy resins, biphenyl type epoxy resins, and bisphenols. Examples thereof include epoxy compounds having two or more functional groups in the molecule, such as A-type epoxy resin, bisphenol F-type epoxy resin, and phenylene skeleton-type epoxy resin. These can be used individually by 1 type or in combination of 2 or more types.

  In the protective film forming layer, the thermosetting resin is preferably 1 to 1000 parts by weight, more preferably 10 to 500 parts by weight, and particularly preferably 20 to 200 parts by weight with respect to 100 parts by weight of the binder polymer component (A). included. When the content of the thermosetting resin is less than 1 part by mass, sufficient adhesiveness may not be obtained. When the content exceeds 1000 parts by mass, the peeling force between the protective film-forming layer and the heat-resistant film increases, and the protective film is formed. Layer transfer failure may occur.

  The thermosetting agent functions as a curing agent for thermosetting resins, particularly epoxy resins. A preferable thermosetting agent includes a compound having two or more functional groups capable of reacting with an epoxy group in one molecule. Examples of the functional group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, and an acid anhydride. Of these, phenolic hydroxyl groups, amino groups, acid anhydrides and the like are preferable, and phenolic hydroxyl groups and amino groups are more preferable.

  Specific examples of the phenolic curing agent include polyfunctional phenolic resin, biphenol, novolac type phenolic resin, dicyclopentadiene type phenolic resin, zylock type phenolic resin, and aralkylphenolic resin. A specific example of the amine curing agent is DICY (dicyandiamide). These can be used individually by 1 type or in mixture of 2 or more types.

  It is preferable that content of a thermosetting agent is 0.1-500 mass parts with respect to 100 mass parts of thermosetting resins, and it is more preferable that it is 1-200 mass parts. If the content of the thermosetting agent is small, the adhesiveness may not be obtained due to insufficient curing, and if it is excessive, the moisture absorption rate of the protective film forming layer may increase and the reliability of the semiconductor device may be reduced.

  When the protective film forming layer contains a thermosetting component as the curable component (B), the protective film forming layer has thermosetting properties. In this case, the protective film forming layer can be cured by heating, but the dicing sheet with the protective film forming layer of the present invention has a heat resistant film. In this case, it is difficult for a residual stress to occur in the laminate of the base film and the heat-resistant film to cause a problem.

  As the energy ray curable component, a compound (energy ray polymerizable compound) containing an energy ray polymerizable group and polymerized and cured when irradiated with energy rays such as ultraviolet rays and electron beams can be used. Specific examples of such energy ray-curable components include trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, or 1,4-butylene glycol. Examples include acrylate compounds such as diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, oligoester acrylate, urethane acrylate oligomer, epoxy-modified acrylate, polyether acrylate, and itaconic acid oligomer. Such a compound has at least one polymerizable double bond in the molecule, and usually has a weight average molecular weight of about 100 to 30,000, preferably about 300 to 10,000. The amount of the energy beam polymerizable compound is preferably 1 to 1500 parts by mass, more preferably 10 to 500 parts by mass, and particularly preferably 20 to 200 parts by mass with respect to 100 parts by mass of the binder polymer component (A). .

  Further, as the energy ray curable component, an energy ray curable polymer in which an energy ray polymerizable group is bonded to the main chain or side chain of the binder polymer component (A) may be used. Such an energy ray curable polymer has a function as a binder polymer component (A) and a function as a curable component (B).

  The main skeleton of the energy ray curable polymer is not particularly limited, and may be an acrylic polymer widely used as the binder polymer component (A), and may be a polyester, a polyether, etc. In view of easy control of physical properties, it is particularly preferable to use an acrylic polymer as the main skeleton.

  The energy beam polymerizable group bonded to the main chain or side chain of the energy beam curable polymer is, for example, a group containing an energy beam polymerizable carbon-carbon double bond, specifically a (meth) acryloyl group or the like. Can be illustrated. The energy beam polymerizable group may be bonded to the energy beam curable polymer via an alkylene group, an alkyleneoxy group, or a polyalkyleneoxy group.

  The weight average molecular weight (Mw) of the energy beam curable polymer to which the energy beam polymerizable group is bonded is preferably 10,000 to 2,000,000, and more preferably 100,000 to 1,500,000. The glass transition temperature (Tg) of the energy ray curable polymer is preferably in the range of −60 to 50 ° C., more preferably −50 to 40 ° C., and particularly preferably −40 to 30 ° C.

  The energy ray curable polymer is, for example, an acrylic polymer containing a functional group such as a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, or an epoxy group, and a substituent that reacts with the functional group and energy ray polymerization. It is obtained by reacting a polymerizable group-containing compound having 1 to 5 reactive carbon-carbon double bonds per molecule. Examples of the substituent that reacts with the functional group include an isocyanate group, a glycidyl group, and a carboxyl group.

  Examples of the polymerizable group-containing compound include (meth) acryloyloxyethyl isocyanate, meta-isopropenyl-α, α-dimethylbenzyl isocyanate, (meth) acryloyl isocyanate, allyl isocyanate, glycidyl (meth) acrylate, (meth) acrylic acid, and the like. Is mentioned.

  Acrylic polymer is a (meth) acrylic monomer having functional groups such as hydroxyl group, carboxyl group, amino group, substituted amino group, and epoxy group, or a derivative thereof, and other (meth) acrylic acid ester monomers copolymerizable therewith. Or it is preferable that it is a copolymer which consists of its derivative (s).

  Examples of the (meth) acrylic monomer having a functional group such as a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, or an epoxy group or a derivative thereof include 2-hydroxyethyl (meth) acrylate having a hydroxyl group, 2-hydroxy Examples thereof include propyl (meth) acrylate; acrylic acid having a carboxyl group, methacrylic acid, itaconic acid; glycidyl methacrylate having an epoxy group, glycidyl acrylate, and the like.

  Examples of other (meth) acrylic acid ester monomers or derivatives thereof copolymerizable with the above monomers include alkyl (meth) acrylates having an alkyl group having 1 to 18 carbon atoms, specifically methyl (meth) acrylate. , Ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and the like; (meth) acrylate having a cyclic skeleton, specifically cyclohexyl (meth) acrylate, Examples include benzyl (meth) acrylate, isobornyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, and imide acrylate. The acrylic polymer may be copolymerized with vinyl acetate, acrylonitrile, styrene or the like.

  Even in the case of using an energy ray curable polymer, the aforementioned energy ray polymerizable compound may be used in combination, or the binder polymer component (A) may be used in combination. The relationship between the amounts of these three components in the protective film-forming layer of the present invention is preferably an energy ray polymerizable compound with respect to 100 parts by mass of the sum of the masses of the energy ray curable polymer and the binder polymer component (A). 1 to 1500 parts by mass, more preferably 10 to 500 parts by mass, particularly preferably 20 to 200 parts by mass.

  By imparting energy beam curability to the protective film forming layer, the protective film forming layer can be cured easily and in a short time, and the production efficiency of the chip with protective film is improved. Conventionally, a protective film for a chip is generally formed of a thermosetting resin such as an epoxy resin, but the curing temperature of the thermosetting resin exceeds 200 ° C., and the curing time requires about 2 hours. It was an obstacle to improving production efficiency. However, since the energy ray-curable protective film forming layer is cured in a short time by energy ray irradiation, a protective film can be easily formed, which can contribute to improvement in production efficiency.

The other component protective film forming layer may contain the following components in addition to the binder polymer component (A) and the curable component (B).

(C) It is preferable that a coloring agent protective film formation layer contains a coloring agent (C). By blending a colorant into the protective film forming layer, when a semiconductor device is incorporated in equipment, infrared rays generated from surrounding devices can be shielded, and malfunction of the semiconductor device due to them can be prevented. Visibility of characters when a product number or the like is printed on a protective film obtained by curing the protective film forming layer is improved. That is, in a semiconductor device or semiconductor chip on which a protective film is formed, the product number or the like is usually printed on the surface of the protective film by a laser marking method (a method in which the surface of the protective film is scraped off by laser light and printed). By containing the colorant (C), a sufficient difference in contrast between the portion of the protective film scraped by the laser beam and the portion that is not removed is obtained, and the visibility is improved. As the colorant (C), organic or inorganic pigments and dyes are used. Among these, black pigments are preferable from the viewpoint of electromagnetic wave and infrared shielding properties. Examples of the black pigment include carbon black, iron oxide, manganese dioxide, aniline black, activated carbon, and the like, but are not limited thereto. Carbon black is particularly preferable from the viewpoint of increasing the reliability of the semiconductor device. A colorant (C) may be used individually by 1 type, and may be used in combination of 2 or more type. The high curability of the protective film-forming layer in the present invention is particularly preferably exhibited when a colorant that lowers the transmittance of both visible light and / or infrared rays and ultraviolet rays is used, and the ultraviolet ray permeability is lowered. . In addition to the above-mentioned black pigment, the colorant that reduces the transparency of both visible light and / or infrared and ultraviolet rays has an absorptivity or reflectivity in the visible light and / or infrared and ultraviolet wavelength regions. If it has, it will not specifically limit.

  The blending amount of the colorant (C) is preferably 0.1 to 35 parts by mass, more preferably 0.5 to 25 parts by mass, particularly preferably 100 parts by mass of the total solid content constituting the protective film forming layer. Is 1-15 parts by mass.

(D) Curing accelerator The curing accelerator (D) is used to adjust the curing rate of the protective film forming layer. The curing accelerator (D) is preferably used particularly when the epoxy resin and the thermosetting agent are used in combination in the curable component (B).

  Preferred curing accelerators include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol; 2-methylimidazole, 2-phenylimidazole, 2-phenyl- Imidazoles such as 4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole; Organic phosphines such as tributylphosphine, diphenylphosphine, triphenylphosphine; And tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphinetetraphenylborate. These can be used individually by 1 type or in mixture of 2 or more types.

  The curing accelerator (D) is preferably contained in an amount of 0.01 to 10 parts by mass, more preferably 0.1 to 1 part by mass with respect to 100 parts by mass of the curable component (B). By containing the curing accelerator (D) in an amount within the above range, it has excellent adhesive properties even when exposed to high temperatures and high humidity, and has high reliability even when exposed to severe reflow conditions. Can be achieved. If the content of the curing accelerator (D) is low, sufficient adhesion characteristics cannot be obtained due to insufficient curing, and if it is excessive, the curing accelerator having a high polarity will adhere to the protective film forming layer under high temperature and high humidity. The reliability of the semiconductor device is lowered by moving to the side and segregating.

(E) Coupling agent The coupling agent (E) may be used to improve the adhesion, adhesion and / or cohesion of the protective film to the chip of the protective film forming layer. Moreover, the water resistance can be improved by using a coupling agent (E), without impairing the heat resistance of the protective film obtained by hardening | curing a protective film formation layer.

  As the coupling agent (E), a compound having a group that reacts with a functional group of the binder polymer component (A), the curable component (B), or the like is preferably used. As the coupling agent (E), a silane coupling agent is desirable. Such coupling agents include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ- (methacryloxypropyl). ) 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, methyltrimethoxy Silane, meth Examples include rutriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazolesilane. These can be used individually by 1 type or in mixture of 2 or more types.

  The coupling agent (E) is usually 0.1 to 20 parts by mass, preferably 0.2 to 10 parts by mass, with respect to 100 parts by mass in total of the binder polymer component (A) and the curable component (B). Preferably, it is contained at a ratio of 0.3 to 5 parts by mass. If the content of the coupling agent (E) is less than 0.1 parts by mass, the above effect may not be obtained, and if it exceeds 20 parts by mass, it may cause outgassing.

(F) Inorganic filler By blending the inorganic filler (F) in the protective film forming layer, it is possible to adjust the thermal expansion coefficient in the protective film after curing, and the protective film after curing with respect to the semiconductor chip The reliability of the semiconductor device can be improved by optimizing the thermal expansion coefficient. Moreover, it becomes possible to reduce the moisture absorption rate of the protective film after hardening.

  Preferable inorganic fillers include powders such as silica, alumina, talc, calcium carbonate, titanium oxide, iron oxide, silicon carbide, boron nitride, beads formed by spheroidizing them, single crystal fibers, and glass fibers. Among these, silica filler and alumina filler are preferable. The said inorganic filler (F) can be used individually or in mixture of 2 or more types. Content of an inorganic filler (F) can be normally adjusted in 1-80 mass parts with respect to 100 mass parts of total solids which comprise a protective film formation layer.

(G) When the photopolymerization initiator protective film forming layer contains an energy ray curable component as the curable component (B) described above, an energy ray such as an ultraviolet ray is irradiated on the use of the energy ray curable component. Curing the curable component. In this case, the polymerization curing time and the amount of light irradiation can be reduced by including the photopolymerization initiator (G) in the composition.

  Specific examples of such photopolymerization initiator (G) include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, and benzoin dimethyl ketal. 2,4-diethylthioxanthone, α-hydroxycyclohexyl phenyl ketone, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, 1,2-diphenylmethane, 2-hydroxy- 2-methyl-1- [4- (1-methylvinyl) phenyl] propanone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide and β-alkyl Examples thereof include roll anthraquinone. A photoinitiator (G) can be used individually by 1 type or in combination of 2 or more types.

  It is preferable that 0.1-10 mass parts is contained with respect to 100 mass parts of energy-beam curable components, and, as for the mixture ratio of a photoinitiator (G), it is more preferable that 1-5 mass parts is contained. If the amount is less than 0.1 parts by mass, satisfactory transferability may not be obtained due to insufficient photopolymerization. If the amount exceeds 10 parts by mass, a residue that does not contribute to photopolymerization is generated, and the curability of the protective film forming layer is increased. May be insufficient.

(H) In order to adjust the initial adhesive force and cohesive force of the crosslinker protective film forming layer, a crosslinker may be added. Examples of the crosslinking agent (H) include organic polyvalent isocyanate compounds and organic polyvalent imine compounds.

  Examples of the organic polyvalent isocyanate compound include aromatic polyvalent isocyanate compounds, aliphatic polyvalent isocyanate compounds, alicyclic polyvalent isocyanate compounds, trimers of these organic polyvalent isocyanate compounds, and these organic polyvalent isocyanate compounds. And a terminal isocyanate urethane prepolymer obtained by reacting a polyol compound with a polyol compound.

  Examples of organic polyvalent isocyanate compounds include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylene diisocyanate, diphenylmethane-4,4′-diisocyanate, diphenylmethane. -2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, trimethylolpropane adduct tolylene diisocyanate and lysine Isocyanates.

  Examples of the organic polyvalent imine compound include N, N′-diphenylmethane-4,4′-bis (1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri -Β-aziridinylpropionate and N, N′-toluene-2,4-bis (1-aziridinecarboxyamide) triethylenemelamine can be exemplified.

  The crosslinking agent (H) is usually from 0.01 to 20 parts by weight, preferably from 0.1 to 10 parts by weight, more preferably from 100 parts by weight of the total amount of the binder polymer component (A) and the energy ray curable polymer. It is used at a ratio of 0.5 to 5 parts by mass.

(I) In addition to the above, various general-purpose additives may be blended in the general- purpose additive protective film forming layer as necessary. Examples of various additives include leveling agents, plasticizers, antistatic agents, antioxidants, ion scavengers, gettering agents, chain transfer agents, and the like.

  The protective film forming layer composed of each component as described above has adhesiveness and curability, and is easily adhered by being pressed against a work (semiconductor wafer, chip, etc.) in an uncured state. Then, after curing, a protective film having high impact resistance can be provided, the adhesive strength is excellent, and a sufficient protective function can be maintained even under severe high temperature and high humidity conditions. The protective film forming layer may have a single layer structure, or may have a multilayer structure as long as one or more layers containing the above components are included.

  The thickness of the protective film forming layer is not particularly limited, but is preferably 3 to 300 μm, more preferably 5 to 250 μm, and particularly preferably 7 to 200 μm. In addition, by making the thickness of the pressure-sensitive adhesive layer 3 and the protective film forming layer 4 substantially the same, there is no height difference on the surface of the dicing sheet, and the winding pressure becomes uniform when the dicing sheet 10 is rolled up. , Curling can be reduced.

  The maximum transmittance at a wavelength of 300 to 1200 nm, which is a scale showing the transmittance of visible light and / or infrared rays and ultraviolet rays in the protective film forming layer, is preferably 20% or less, more preferably 0 to 15%. More preferably, it is more than 0% and 10% or less, particularly preferably 0.001 to 8%. By setting the maximum transmittance of the protective film forming layer at a wavelength of 300 to 1200 nm in the above range, when the protective film forming layer contains an energy ray curable component (particularly an ultraviolet curable component), Excellent curability. In addition, since the transparency in the visible light wavelength region and / or the infrared wavelength region is low, effects such as prevention of malfunction caused by infrared rays of the semiconductor device and improvement in the visibility of printing can be obtained. The maximum transmittance of the protective film forming layer at a wavelength of 300 to 1200 nm can be adjusted by the colorant (C). In addition, the maximum transmittance of the protective film forming layer is the total light transmission at 300 to 1200 nm of the cured protective film forming layer (thickness 25 μm) using a UV-vis spectrum inspection apparatus (manufactured by Shimadzu Corporation). The transmittance was measured, and the highest transmittance (maximum transmittance) was obtained.

(Peeling sheet)
The dicing sheet with a protective film forming layer may be provided with a release sheet for avoiding contact with the outside of the surface until it is used. As the release sheet, for example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, polybutylene terephthalate film, Polyurethane film, ethylene vinyl acetate copolymer film, ionomer resin film, ethylene / (meth) acrylic acid copolymer film, ethylene / (meth) acrylic acid ester copolymer film, polystyrene film, polycarbonate film, polyimide film, fluorine A transparent film such as a resin film is used. These crosslinked films are also used. Furthermore, these laminated films may be sufficient. Moreover, the film which colored these, an opaque film, etc. can be used. Examples of the release agent include release agents such as silicone-based, fluorine-based, and long-chain alkyl group-containing carbamates.

  The thickness of the release sheet is usually about 10 to 500 μm, preferably about 15 to 300 μm, and particularly preferably about 20 to 250 μm. Moreover, the thickness of the dicing sheet with a protective film forming layer is usually 1 to 500 μm, preferably 5 to 300 μm, and particularly preferably about 10 to 150 μm.

(Dicing sheet with protective film forming layer)
The following method is mentioned as a manufacturing method of the dicing sheet 10 with a protective film formation layer. First, a laminated sheet of the base film 1 and the heat resistant film 2 is prepared. The base film and the heat-resistant film may be directly laminated by means such as extrusion molding, or may be firmly joined by an adhesive or a strong pressure-sensitive adhesive. The groove | channel 5 may be provided so that the area | region where provision of the protective film formation layer was planned in the stage which prepared the laminated sheet of such a base film and a heat-resistant film could be provided. Next, the protective film forming layer 4 is formed on the inner peripheral surface of the heat-resistant film 2 of the laminated sheet, and the annular pressure-sensitive adhesive layer 3 is formed on the outer peripheral surface of the heat-resistant film. The protective film-forming layer can be obtained by coating and drying a protective film-forming layer composition obtained by mixing each of the above components in an appropriate solvent on an appropriate release film. Also, a protective film-forming layer composition is applied onto a heat-resistant film, dried to form a film, and this is bonded to another release sheet and sandwiched between the laminated sheet (base film / heat-resistant film) and the release sheet. It is good also as a state (base film / heat-resistant film / protective film formation layer / release sheet).

  Next, in the case of the sandwiched state, one release sheet is peeled off. Then, it is cut into a circle that is the same size or slightly larger than the workpiece (for example, a semiconductor wafer) to which the protective film forming layer is to be attached, and the periphery of the protective film forming layer that has been cut into a circular shape is scraped off. A circular protective film forming layer is formed on the peripheral surface.

  The groove 5 for completely cutting the heat-resistant film may be formed along the outer periphery of the protective film-forming layer by cutting the heat-resistant film at the same time as the protective film-forming layer is die-cut. In this case, since the heat-resistant film is usually bonded to the base film so as not to be peeled off, only the protective film forming layer outside the outer peripheral portion of the groove 5 is removed, and the same shape as the planar shape of the groove 5 A protective film forming layer is obtained. The groove 5 may be formed after the protective film forming layer is punched out, or may have a similar shape or a non-similar shape other than the same shape as the protective film forming layer.

  Next, the cyclic | annular adhesive layer 3 is prepared. The pressure-sensitive adhesive layer is usually provided in a form in which release sheets treated with a silicone release agent or the like are laminated on both sides. The release sheet plays a role of protecting the pressure-sensitive adhesive layer and providing support. If the release sheets laminated on both sides are configured to have a difference in release force as in the light release type and the heavy release type, the workability at the time of creating the dicing sheet with the protective film forming layer is preferably improved. That is, as a release sheet, a light release type release sheet and a heavy release type release sheet are used to sandwich an adhesive layer, and a light release type release sheet side is used to remove a light release type release sheet. The pressure-sensitive adhesive layer and the pressure-sensitive adhesive layer are punched in a circular shape, and the light release type release sheet and the pressure-sensitive adhesive layer punched in a circular shape are scraped to form an opening. Next, the light release type release sheet on the adhesive layer surrounding the opening is removed to expose the adhesive layer. Then, the laminated sheet obtained by laminating the protective film forming layer obtained above and the exposed surface of the pressure-sensitive adhesive layer so that the circularly punched opening and the circular protective film forming layer are concentric. Laminate to make a laminate.

  Thereafter, in accordance with the outer diameter of the margin for the ring frame, the die is cut concentrically with the opening and the laminate, and the periphery of the die-cut laminate is removed. Finally, the heavy release type release sheet is released to obtain the dicing sheet with a protective film forming layer of the present invention. As shown in FIG. 1, the dicing sheet 10 with a protective film-forming layer of the present invention has a protective film-forming layer on the inner peripheral surface of the heat-resistant film of a laminated sheet having a base film and a heat-resistant film. The pressure-sensitive adhesive layer 3 is provided on the outer peripheral surface. The adhesive layer 3 is attached to the ring frame 6. The inner diameter (opening diameter) of the annular pressure-sensitive adhesive layer 3 formed on the outer peripheral surface of the heat-resistant film 2 is formed to be larger than the outer diameter of the protective film forming layer 4. The width of the pressure-sensitive adhesive layer 2 formed in an annular shape is preferably 0.5 to 20 mm.

  In the above production method, the pressure-sensitive adhesive layer provided on the release sheet is transferred to the laminated sheet of the base film provided with the protective film-forming layer and the heat-resistant film, thereby providing the protective film-forming layer of the present invention. Although the dicing sheet was obtained, the protective film formation layer of the present invention was formed by transferring the protective film formation layer provided on the release sheet to the laminated sheet of the base film provided with the adhesive layer and the heat-resistant film. A layer can also be obtained.

  In the dicing sheet with a protective film forming layer as described above, the total light transmittance at a wavelength of 532 nm and a wavelength of 1064 nm in the laminated sheet portion of the base film and the heat-resistant film is preferably 70% or more, more preferably 75% or more. is there. By setting the total light transmittance at a wavelength of 532 nm and a wavelength of 1064 nm in the laminated sheet portion of the base film and the heat-resistant film within the above range, after the dicing sheet with a protective film forming layer is attached to the semiconductor wafer, from the base film side Laser marking on the protective film can be performed by irradiating the laser beam. Therefore, since laser marking can be performed with the wafer fixed to the dicing sheet, warpage of the wafer is suppressed and printing accuracy is improved.

  In the dicing sheet with a protective film forming layer as described above, the substrate film and the heat-resistant film may be provided with a plurality of fine through holes. By providing the through hole, it is possible to suppress the generation of foreign matters caused by the gas generated when laser marking is performed on the protective film.

(Chip manufacturing method)
Next, a method of using the dicing sheet with a protective film forming layer according to the present invention will be described taking as an example the case where the sheet is applied to the manufacture of a chip (for example, a semiconductor chip).

A manufacturing method of a semiconductor chip using a dicing sheet with a protective film forming layer according to the present invention is a method in which a protective film forming layer of the above sheet is pasted on the back surface of a semiconductor wafer (work) on which a circuit is formed. A semiconductor chip having a protective film on the back surface is obtained through steps (1), (2), and (3) in this order.
Step (1): The protective film forming layer is cured to obtain a protective film.
Step (2): dicing workpiece and protective film forming layer (or protective film),
Step (3): peeling off the protective film and the heat-resistant film.

In addition to the above steps (1) to (3), the method for manufacturing a semiconductor chip according to the present invention further includes the following step (4), and in any step after the above step (1), Step (4) can also be performed.
Step (4): Laser printing on the protective film.

  The step (4) is preferably performed between the step (1) and the step (2). By performing laser printing on the protective film forming layer after curing, the printing accuracy is excellent. On the other hand, when the process is performed after the process (2) and before the process (3), the printing accuracy may be deteriorated due to a minute positional deviation of the chip during dicing. Moreover, when it is performed after the step (3), it is necessary to individually perform laser printing on each chip, and the process becomes complicated.

  The semiconductor wafer may be a silicon wafer or a compound semiconductor wafer such as gallium / arsenic. Formation of a circuit on the wafer surface can be performed by various methods including conventionally used methods such as an etching method and a lift-off method. Next, the opposite surface (back surface) of the circuit surface of the semiconductor wafer is ground. The grinding method is not particularly limited, and grinding may be performed by a known means using a grinder or the like. At the time of back surface grinding, an adhesive sheet called a surface protection sheet is attached to the circuit surface in order to protect the circuit on the surface. In the back surface grinding, the circuit surface side (that is, the surface protection sheet side) of the wafer is fixed by a chuck table or the like, and the back surface side on which no circuit is formed is ground by a grinder. The thickness of the wafer after grinding is not particularly limited, but is usually about 20 to 500 μm. Thereafter, if necessary, the crushed layer generated during back grinding is removed. The crushed layer is removed by chemical etching, plasma etching, or the like.

  Subsequently, the protective film formation layer of the said dicing sheet with a protective film formation layer is affixed on the back surface of a semiconductor wafer. Thereafter, steps (1), (2), and (3) are performed in this order. About the outline | summary of this process, the similar process is explained in full detail in Unexamined-Japanese-Patent No. 2002-280329.

  First, the protective film formation layer of the said dicing sheet with a protective film formation layer is affixed on the back surface of the semiconductor wafer in which the circuit was formed on the surface. Next, the protective film forming layer is cured, and a protective film is formed on the entire surface of the wafer. By sticking the protective film-forming layer before curing to the semiconductor wafer, the protective film-forming layer is well adapted to the sticking surface of the wafer, and the adhesion between the protective film and the semiconductor chip is improved. In addition, shrinkage deformation of the dicing sheet with the protective film forming layer is suppressed when the protective film forming layer is cured. Since the protective film forming layer contains the curable component (B), the protective film forming layer is generally cured by heat curing or energy ray irradiation. In addition, when the thermosetting component and the energy ray curable component are blended in the protective film forming layer, the protective film forming layer can be cured by both heating and energy ray irradiation. Curing by beam irradiation may be performed simultaneously or sequentially. As a result, a protective film made of a cured resin is formed on the back surface of the wafer, and the strength is improved as compared with the case of the wafer alone, so that damage to the thin wafer during handling can be reduced. In addition, the thickness of the protective film is excellent compared to a coating method in which a coating liquid for the protective film is directly applied to the back surface of the wafer or chip.

  When the protective film forming layer is thermosetting, the occurrence of residual stress of the base film due to deformation during thermosetting of the dicing sheet with the protective film forming layer of the present invention is suppressed, and the chip interval after dicing is reduced. The effect of preventing narrowing is preferably exhibited. Therefore, the protective film forming layer is thermosetting, and the manufacturing method in which dicing and pick-up (peeling of the adhesive sheet from the protective film forming layer) are performed after the thermosetting of the protective film forming layer, that is, (1), (2 It is preferable to use the dicing sheet with a protective film forming layer of the present invention in the production method in which the steps are carried out in the order of (3).

  Next, it is preferable to perform laser printing on the cured protective film forming layer (protective film). Laser printing is performed by a laser marking method, and a product number or the like is marked on the protective film by scraping the surface of the protective film through the base film and the heat-resistant film by irradiation with laser light. According to the dicing sheet with a protective film forming layer of the present invention, since the warpage of the wafer can be suppressed even with an extremely thin wafer, the focal point of the laser beam is accurately determined and marking can be performed with high accuracy.

  Next, the semiconductor wafer is diced for each circuit formed on the wafer surface. Dicing is performed so as to cut both the wafer and the protective film. The dicing method is not particularly limited. For example, after dicing the wafer, the peripheral portion (adhesive layer 3) of the dicing sheet with the protective film forming layer is fixed with a ring frame, and then a rotating round blade such as a dicing blade is used. And a known method for forming a wafer into chips.

  By completely cutting the heat-resistant film 2 when cutting the wafer and the protective film, the base film 1 can be expanded after dicing, the chip interval is separated, and chip pick-up becomes easy.

  Thereafter, the dicing sheet is expanded. When an extensible base material is used as the base material of the dicing sheet in the present invention, the dicing sheet has excellent expandability, and the chip pick-up property is improved.

  The diced semiconductor chip with a protective film is picked up by a general-purpose means such as a collet and peeled off at the interface between the protective film and the heat-resistant film. As a result, a semiconductor chip having a protective film on the back surface (semiconductor chip with protective film) is obtained. According to the present invention, it is possible to easily form a protective film having a highly uniform thickness on the back surface of the chip, and cracks after the dicing process and packaging are less likely to occur. In addition, according to the present invention, a chip with a protective film is obtained without replacing the wafer on which the protective film is formed with the dicing tape, as compared with the conventional process in which the wafer is diced. Therefore, the manufacturing process can be simplified. Further, since the wafer weakened by grinding is not handled alone, the risk of wafer breakage is reduced. Further, the thinned wafer may be warped due to curing shrinkage of the protective film. However, since the wafer is held on the ring frame via the adhesive sheet, the warpage can be suppressed. Then, the semiconductor device can be manufactured by mounting the semiconductor chip on a predetermined base by the face-down method. Further, a semiconductor device can be manufactured by adhering a semiconductor chip having a protective film on the back surface to another member (on the chip mounting portion) such as a die pad portion or another semiconductor chip.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples. In the following examples and comparative examples, <chip spacing retention and expandability>, <thermal shrinkage of base film and heat-resistant film>, <melting point of base film and heat-resistant film>, and <base film The elongation at break and 25% stress> were measured and evaluated as follows. Moreover, the following <composition for protective film formation layer>, <adhesive composition>, <base film>, and <heat-resistant film> were used.

<Chip spacing retention and expandability>
The protective film forming layer of the dicing sheet with protective film forming layer was attached to a silicon wafer (diameter 8 inches, thickness 200 μm, # 2000 polishing), and the pressure-sensitive adhesive layer on the outer periphery of the dicing sheet was attached to the ring frame. Subsequently, it heated at 130 degreeC for 2 hours, the protective film formation layer was hardened, and the silicon wafer with a protective film was diced into the chip size of 5 mm x 5 mm. At this time, in the examples, the wafer, the protective film, and the heat-resistant film were fully cut. The width of the used dicing blade is 30 μm. At this time, the distance between adjacent chips was measured with a digital microscope at the time after dicing. The measurement was performed with respect to the distance between the chip adjacent in the vertical direction (the chip adjacent on the lower side) and the chip adjacent in the horizontal direction (the chip on the right side), and the average of the measurement results of the five chips was taken. The case where the distance between the chips was 20 μm or more was designated as “A”, and the case where the distance between the chips was less than 20 μm was designated as “B”. Thereafter, using a die bonder (Bestem-D02 manufactured by Canon Machinery Co., Ltd.), expansion was performed with a withdrawal amount of 3 mm. Check if the base film is torn at the time of expansion, “A” if expansion is possible and the base film is not torn, and if expansion is not possible or if the base film is torn. B ".

<Heat shrinkage of base film and heat-resistant film>
The base film and the heat-resistant film were each cut into 10 cm × 10 cm and put into a hot air oven (130 ° C., 2 hours). Thereafter, the base film and the heat-resistant film were taken out, the dimensions of the film were measured, and the thermal shrinkage rate was obtained by the following formula.
Heat shrinkage (%) = {(area of predose film) - (the area of the film after on)} / charged surface product × 100 before the film

<Melting point of base film and heat-resistant film>
The melting point of the base film was measured by a method based on JIS K7121: 1987.

<Break elongation and 25% stress of base film>
The elongation at break of the base film is determined by using a universal tensile testing machine (Tensilon RTA-T-2M manufactured by Orientec Co., Ltd.) in accordance with JIS K7161: 1994 under an environment of 23 ° C. and 50% humidity. The measurement was performed at 200 mm / min and a sample length of 50 mm. The measurement was performed in both the MD direction and the CD direction. The elongation at break is the elongation at break. The 25% stress of the base film was calculated by dividing the force measured at 12.5 mm elongation by the cross-sectional area of the sample.

<Composition for protective film forming layer>
Each component and blending amount constituting the protective film forming layer are shown below (each component / blending amount).
(A) Binder polymer component: acrylic polymer consisting of 55 parts by mass of n-butyl acrylate, 15 parts by mass of methyl methacrylate, 20 parts by mass of glycidyl methacrylate, and 15 parts by mass of 2-hydroxyethyl acrylate (weight average molecular weight: 900,000, glass transition (Temperature: -28 ° C.) / 100 parts by mass (B) Curing component (B1) 50 parts by mass of bisphenol A type epoxy resin (epoxy equivalent 180-200), dicyclopentadiene type epoxy resin (Dainippon Ink Chemical Co., Ltd.) (Epicron HP-7200HH) 50 parts by mass, thermosetting component / (total 100 parts by mass)
(B2) Thermally active latent epoxy resin curing agent Dicyandiamide (Asahi Denka, Adeka Hardener 3636AS): 2.8 parts by weight (C) Colorant: 10.0 parts by mass of carbon black (D) Curing accelerator: 2-phenyl -4,5-dihydroxymethylimidazole (manufactured by Shikoku Kasei Kogyo Co., Ltd., Curesol 2PHZ) 2.8 parts by weight (E) Silane coupling agent: A-1110 (Nihon Unicar) / 1 weight (F) Silica filler: fused quartz Filler (average particle size 8μm) / 300 parts by weight

<Adhesive composition for adhesive layer>
Silicone adhesive comprising 60 parts by mass of KS847H manufactured by Shin-Etsu Chemical Co., Ltd., 30 parts by mass of SD4584 manufactured by Toray Dow Silicone Co., Ltd. and 0.5 parts by mass of SRX212 manufactured by Toray Dow Silicone Co., Ltd.

<Adhesive composition for laminated sheet>
Acrylic adhesive comprising 91 parts by mass of butyl acrylate, 100 parts by mass of a copolymer consisting of 9 parts by mass of acrylic acid, 1 part by mass of a crosslinking agent (isocyanate), and an organic solvent

<Base film>
100 μm thick polypropylene film (Toyobo Co., Ltd., pyrene film CTP1147)

<Heat resistant film>
A film obtained by subjecting the surface of a 50 μm thick polyimide film (Toray DuPont, Kapton 200H) to a release treatment

Example 1
Each said component of the composition for protective film formation layers was mix | blended with the said compounding quantity. Moreover, the polyethylene terephthalate film (SP-P502010 by Lintec Corporation, thickness 50micrometer) which peeled on one side was prepared as a peeling sheet.

  A methyl ethyl ketone solution (solid concentration: 61% by weight) of the composition for forming a protective film is applied onto the release-treated surface of the release sheet so as to have a thickness of 25 μm and dried (drying condition: 120 ° C. in an oven). 3 minutes) to form a protective film forming layer on the release sheet.

  Separately from the above, a laminated sheet of a base film and a heat-resistant film was prepared. On the non-peeled surface of the heat-resistant film, the pressure-sensitive adhesive composition for laminated sheets was applied so that the thickness after drying was 10 μm, and dried by heating at 100 ° C. for 1 minute. Subsequently, the adhesive of the heat-resistant film in which the adhesive was formed was bonded to the base film to produce a laminated sheet of the base film and the heat-resistant film.

  Subsequently, the protective film formation layer on the said peeling sheet was laminated | stacked on the heat-resistant film side (peeling process surface) of the said lamination sheet. The release sheet, protective film forming layer, and heat-resistant film were die-cut to the same size (8 inches in diameter) as the silicon wafer. Then, the outer periphery of the release sheet and the protective film forming layer punched in a round shape was removed, and the heat-resistant film was left without removing the residue. Thereafter, the release sheet that had been punched into the same shape as the protective film forming layer was removed. As a result, a circular protective film forming layer was obtained on the heat resistant film, and a groove for completely cutting the heat resistant film was formed along the outer periphery of the protective film forming layer.

  In addition to the above, an annular pressure-sensitive adhesive layer was prepared as follows. As the release sheet, a polyethylene terephthalate film (SP-PET38E-0010YC manufactured by Lintec) on which one side was subjected to a release treatment, and a polyethylene terephthalate film (SP-PET38E-0010YC manufactured by Lintec) were prepared as another release sheet. The toluene solution (solid concentration 35% by weight) of the pressure-sensitive adhesive for the pressure-sensitive adhesive layer is applied on the release-treated surface of the release sheet so as to have a thickness of 5 μm and dried (drying conditions: 120 ° C. in an oven, 3 minutes) ), And another release sheet was pasted. Next, in accordance with the inner diameter of the ring frame of 255 μm, the other release sheet was cut in a circular shape, and the pressure-sensitive adhesive layer and the other release sheet were removed from the punched part to form an opening. Next, the release sheet on the pressure-sensitive adhesive layer surrounding the opening is removed to expose the pressure-sensitive adhesive layer, and the heat-resistant film and the pressure-sensitive adhesive layer are formed so that the opening and the protective film forming layer are concentric. The exposed surface was laminated to form a laminate.

  The outer diameter of the glue for the ring frame was set to 260 mm so that the outer diameter (275 mm) of the ring frame was not exceeded, and the laminate was die-cut in this size concentrically with the opening and the protective film forming layer. Thereafter, the remaining release sheet was peeled off to obtain a dicing sheet with a protective film forming layer. Each evaluation result is shown in Table 1.

(Example 2)
Each said component of the composition for protective film formation layers was mix | blended with the said compounding quantity. Moreover, the polyethylene terephthalate film (SP-P502010 by Lintec Corporation, thickness 50micrometer) which peeled on one side was prepared as a peeling sheet.

  A methyl ethyl ketone solution (solid concentration: 61% by weight) of the composition for forming a protective film is applied onto the release-treated surface of the release sheet so as to have a thickness of 25 μm and dried (drying condition: 120 ° C. in an oven). 3 minutes) to form a protective film forming layer on the release sheet. To this protective film forming layer, a release treatment surface of a polyethylene terephthalate film (SP-PET 381031, thickness 38 μm) was bonded as another release sheet. Next, the die is cut to the same size as the silicon wafer (diameter 8 inches) so as to cut only the protective film forming layer and other release sheets while leaving the release sheet, and then protection of the portion excluding the die-cut shape portion. The film-forming layer and other release sheets were removed, and a protective film-forming layer and other release sheets that were punched in a circle on the release sheet were obtained.

  As a heat-resistant film, a base film is formed in the same manner as in Example 1 except that a pressure-sensitive adhesive is formed on one surface of a 50 μm-thick polyimide film (Toray DuPont, Kapton 200H) that has not been peeled. A laminated sheet with a heat resistant film was prepared. Next, only the heat-resistant film was die-cut to the same size as the silicon wafer to form grooves.

  The other release sheet on the protective film forming layer is peeled off, the heat-resistant film of the above laminated sheet and the protective film forming layer are laminated so that the outer periphery of the protective film forming layer and the groove coincide with each other, and then the release sheet is removed. did. As a result, a circular protective film forming layer was obtained on the heat resistant film, and a groove for completely cutting the heat resistant film was formed along the outer periphery of the protective film forming layer.

  Then, the adhesive layer was provided like Example 1, the peeling sheet was removed, and the dicing sheet with a protective film formation layer was obtained. Each evaluation result is shown in Table 1.

(Example 3)
A dicing sheet with a protective film forming layer was obtained in the same manner as in Example 2 except that a polypropylene film having a thickness of 50 μm (Santox CP KT manufactured by Santox Co., Ltd.) was used as the base film. Each evaluation result is shown in Table 1.

Example 4
Dicing with a protective film forming layer was carried out in the same manner as in Example 2 except that when the heat-resistant film was punched, six non-grooved portions having a length of 0.7 mm were provided on the outer periphery of the groove at regular intervals. A sheet was obtained. The non-grooved portion of the groove was broken by the expand and could be expanded. Each evaluation result is shown in Table 1.

(Comparative Example 1)
A dicing with a protective film forming layer was performed in the same manner as in Example 1 except that a film made only of a 50 μm-thick polyimide film (manufactured by Toray DuPont Co., Ltd., Kapton 200H) was used instead of the laminated sheet. A sheet was obtained. Each evaluation result is shown in Table 1. In addition, about the various characteristics of the film, it described in the column of the heat-resistant film.

(Comparative Example 2)
Instead of the laminated sheet, a protective film-forming layer and a pressure-sensitive adhesive layer were laminated on the surface not subjected to the peeling treatment using a polypropylene film (Santox Co., Ltd., RS72 # 75) subjected to the peeling treatment having a thickness of 75 μm. Except for the above, a dicing sheet with a protective film forming layer was obtained in the same manner as in Example 1. Each evaluation result is shown in Table 1. In addition, about the various characteristics of the film, it described in the column of the base film.

  In the table, PP means polypropylene and PI means polyimide.

DESCRIPTION OF SYMBOLS 1 ... Base film 2 ... Heat-resistant film 3 ... Adhesive layer 4 ... Protective film formation layer 5 ... Groove 6 ... Ring frame 10 ... Dicing sheet with protective film formation layer

Claims (9)

It has a protective film forming layer on the inner peripheral part of the heat resistant film surface of the laminated sheet having the base film and the heat resistant film,
Having an adhesive layer on the outer peripheral surface of the heat-resistant film,
The melting point of the heat-resistant film has no more than or melting point 130 ° C., Ri thermal shrinkage -1 + 1% der of heat-resistant film at the time of 2 hours heating at 130 ° C.,
In any of the MD and CD directions of the base film also, the tensile elongation at break of the measurement is at least 100%, and a dicing sheet with the protective film forming layer 25% stress Ru der less 100 MPa.   The dicing sheet with a protective film forming layer according to claim 1, wherein a groove that surrounds the protective film forming layer and completely cuts the heat resistant film in the thickness direction is formed. No melting point exceeds or melting point 130 ° C. of the substrate film, a protective film according to claim 1 or 2 thermal shrinkage of the base film at the time of 2 hours heating at 130 ° C. is -5 + 5% Dicing sheet with forming layer.   The dicing sheet with a protective film forming layer according to any one of claims 1 to 3, wherein the laminated sheet has a total light transmittance of 70% or more at wavelengths of 532 nm and 1064 nm.   The dicing sheet with a protective film forming layer according to any one of claims 1 to 4, wherein the protective film forming layer contains a binder polymer component and a curable component. The protective film forming layer contains a colorant,
The dicing sheet with a protective film forming layer according to any one of claims 1 to 5, wherein the total light transmittance of the protective film forming layer at a wavelength of 300 to 1200 nm is 20% or less. The chip which affixes the protective film formation layer of the dicing sheet with a protective film formation layer in any one of Claims 1-6 to a workpiece | work, and performs the following processes in order of (1), (2), (3). Manufacturing method:
Step (1): The protective film forming layer is cured to obtain a protective film.
Step (2): dicing the workpiece and the protective film forming layer or the protective film,
Step (3): peeling off the protective film and the heat-resistant film. The chip manufacturing method according to claim 7, wherein the following step (4) is performed in any step after the step (1):
Step (4): Laser printing on the protective film. The chip manufacturing method according to claim 7 or 8, wherein the heat-resistant film is fully cut in the step ( 2 ).

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