JP2015099825A - Method of manufacturing chip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a chip capable of manufacturing a chip on whose rear face side a protection film is formed, by using a wafer division method of a stealth dicing system.SOLUTION: A method includes: a protection member adhesion step of adhering a protection member 2 onto a surface 1A of a semiconductor wafer 1; an altered layer formation step of irradiating the semiconductor wafer 1 with a laser beam having permeability along a division schedule line from a rear face 1B side of the semiconductor wafer 1 on which the protection member 2 is adhered to form an altered layer; a polishing step of polishing the rear face 1B of the semiconductor wafer 1 on which the protection member is adhered; a step of forming a thermosetting protection film formation layer 3 on the rear face side of the semiconductor wafer 1; a dicing sheet adhesion step of adhering a dicing sheet 4 on the rear face 1B side of the semiconductor wafer 1 on which the altered layer is formed; a protection member peeling step of peeling out the protection member 2; and a semiconductor wafer division step of dividing the semiconductor wafer into a plurality of chips.

Description

  The present invention relates to a method for manufacturing a chip.

  In a semiconductor device manufacturing process, a new method has been proposed as a method of dividing a wafer having a functional element on the surface into a plurality of chips. That is, along the planned dividing lines arranged in a lattice pattern on the surface of the wafer, a deteriorated layer is continuously formed by irradiating the wafer with a pulsed laser beam having transparency, and this deteriorated layer is formed. There has been proposed a so-called stealth dicing method of dividing a semiconductor wafer along a planned dividing line whose strength has been reduced by the above (see, for example, Patent Document 1).

  In the wafer dividing method described in Patent Document 1, after polishing the back surface of the wafer having a protective member attached to the front surface, a pulsed laser beam having transparency is irradiated from the back surface side along the planned dividing line, and the altered layer Form. Then, an adhesive film for die bonding, that is, for fixing the chip to the substrate at the time of mounting the chip is attached to the back surface of the wafer on which the deteriorated layer is formed. Further, the adhesive film side is attached to a dicing tape attached to an annular frame. Then, it divides | segments into each chip | tip and picks up each chip | tip. The picked-up chip is fixed to the substrate with the back side to which the adhesive film is attached facing the substrate side (die bonding step).

JP 2005-223282 A

  In the dividing method described in Patent Document 1, an adhesive film for die bonding is attached to the back side of the wafer. However, in a chip manufacturing method using a stealth dicing method, a method for manufacturing a chip by dividing a wafer after forming a protective film for protecting the chip on the back side of the wafer has been established. Absent.

  An object of the present invention is to provide a chip manufacturing method capable of manufacturing a chip having a protective film formed on the back surface side by using a stealth dicing wafer dividing method.

The first aspect of the chip manufacturing method of the present invention is:
Attaching a protective member to the surface of the wafer on which a plurality of functional elements are formed;
From the back side of the wafer to which the protective member is adhered, a laser beam having transparency to the wafer is irradiated along the scheduled division line set between the functional elements, and the inside of the wafer is altered. Forming a layer;
Polishing the back surface of the wafer to which the protective member is attached;
Forming a protective film forming layer having thermosetting on the back side of the wafer on which the altered layer is formed;
A step of adhering a dicing sheet comprising a support substrate and an adhesive layer on the back side of the wafer on which the protective film forming layer is formed;
After pasting the dicing sheet, a step of peeling the protective member stuck to the surface of the wafer;
Dividing the wafer into a plurality of chips along the division line.

The second aspect of the chip manufacturing method of the present invention is:
Attaching a protective member to the surface of the wafer on which a plurality of functional elements are formed;
From the back side of the wafer to which the protective member is adhered, a laser beam having transparency to the wafer is irradiated along the scheduled division line set between the functional elements, and the inside of the wafer is altered. Forming a layer;
Polishing the back surface of the wafer to which the protective member is attached;
A multilayer substrate sheet comprising a supporting substrate, a pressure-sensitive adhesive layer laminated on the supporting substrate, and a protective film-forming layer laminated on the pressure-sensitive adhesive layer and having thermosetting properties, and the protective film-forming layer is the wafer A step of adhering to the back side of the wafer on which the altered layer is formed, so as to be formed on the back side of
After pasting the multilayer film sheet, the step of peeling the protective member stuck to the surface of the wafer;
Dividing the wafer into a plurality of chips along the division line.

In the chip manufacturing method of the present invention,
Heating the wafer on which the protective film forming layer and the dicing sheet are laminated, or the wafer on which the multilayer film sheet is adhered, curing the protective film forming layer, and forming a protective film; It is preferable to implement.

In the chip manufacturing method of the present invention,
The step of heating the wafer is preferably performed after the step of peeling the protective member.

In the chip manufacturing method of the present invention,
It is preferable to carry out a step of marking the protective film by irradiating the protective film with a marking laser beam from the support substrate side.

In the chip manufacturing method of the present invention,
Preferably, after the step of forming the deteriorated layer inside the wafer, a step of polishing the back surface of the wafer is performed to remove the deteriorated layer.

In the chip manufacturing method of the present invention, a protective film forming layer having thermosetting properties and a supporting substrate are laminated on the back side of the wafer.
Accordingly, in the chip manufacturing method in which the wafer is divided into a plurality of chips by adopting the stealth dicing method, a thermosetting protective film forming layer for forming a protective film on the back surface side of the chip is provided on the back surface side of the wafer. Can be formed. By heating and curing the protective film forming layer, a chip having a protective film formed on the back surface side can be manufactured.

In the chip manufacturing method of the present invention, when the step of heat-curing the protective film forming layer is performed, a chip having a protective film formed on the back surface side can be manufactured. Thereby, when the manufactured chip is taken out individually or mounted on a semiconductor device, the chip can be protected by the protective film formed on the back surface side.
In addition, if a chip on which a protective film forming layer before heat curing is formed is taken out or mounted on a semiconductor device, the surface of the protective film forming layer may have scratches or marks and the appearance may deteriorate. There is. On the other hand, in the chip manufacturing method, the occurrence of the above-described problems can be suppressed by forming the protective film by heating and curing the protective film forming layer.

  In the chip manufacturing method of the present invention, when the step of heating the wafer is performed after the step of peeling the protective member, the heating step is performed after the protective member is peeled off. A commonly used material that is not used can be used, and the cost can be reduced.

  In the chip manufacturing method of the present invention, when the step of marking the protective film is performed, various kinds of information such as the product number and the serial number of each chip are marked on the surface of the protective film formed on the back surface of the chip. be able to.

In the chip manufacturing method of the present invention, it is preferable to polish the back surface of the wafer after forming the deteriorated layer.
Here, when the end surface of the chip is not smooth and there is a chip, the chip may be cracked by the chip.
On the other hand, the wafer can be broken along the deteriorated layer by polishing the wafer after forming the deteriorated layer. Further, when the wafer is polished, the deteriorated layer can be polished and removed together with the wafer, and the end face of the chip can be smoothed. As a result, it is possible to prevent the occurrence of the cracks described above and improve the chip strength.

The perspective view which shows the semiconductor wafer of 1st Embodiment typically. The cross-sectional schematic which shows typically the sticking process of the protection member of 1st Embodiment. FIG. 3 is a schematic cross-sectional view schematically showing a deteriorated layer forming step of the first embodiment. The cross-sectional schematic diagram which shows the grinding | polishing process of 1st Embodiment typically. Sectional schematic which shows typically the formation process of the protective film formation layer of 1st Embodiment. The cross-sectional schematic which shows typically the dicing sheet sticking process of 1st Embodiment. The cross-sectional schematic diagram which shows typically the peeling process of the protection member of 1st Embodiment. The cross-sectional schematic diagram which shows typically the marking process of 1st Embodiment. Sectional schematic which shows typically the semiconductor wafer division | segmentation process of 1st Embodiment. Sectional schematic which shows typically the pick-up process of 1st Embodiment. FIG. 3 is a schematic cross-sectional view schematically showing a chip mounted on the circuit board of the first embodiment. Sectional schematic which shows typically the lamination sheet sticking process of 2nd Embodiment.

Embodiments of the present invention will be described below, but the scope of the present invention is not limited to these examples. In the present embodiment, a case where a semiconductor wafer is used as an example of a wafer will be described.
[First Embodiment]
In the chip manufacturing method according to the present embodiment, from the back surface side of the semiconductor wafer, the focal point is aligned with the inside of the semiconductor wafer, for example, an infrared laser beam is irradiated, and the deteriorated layer having a reduced strength is formed inside the semiconductor wafer. Form. Then, the semiconductor wafer is divided along the altered layer.
Under the present circumstances, after forming a thermosetting protective film formation layer in the back surface of a semiconductor wafer, a dicing sheet provided with a support base material and an adhesive layer is arranged on the back surface side of a semiconductor wafer. And after heating a semiconductor wafer and forming a protective film by hardening a protective film formation layer, a dicing sheet is expanded and a semiconductor wafer is divided into a plurality of chips with a protective film.
Hereinafter, the manufacturing method of the chip according to the present embodiment will be described in detail.

  FIG. 1 is a perspective view schematically showing a semiconductor wafer having a plurality of functional elements formed on the surface. 2 to 9 are views schematically showing a cross section of the semiconductor wafer in a corresponding step of the chip manufacturing method of the present embodiment.

<Chip manufacturing method>
-Sticking process of protective member The semiconductor wafer 1 has a substrate 10 such as silicon and a plurality of functional elements 11 formed on the surface 1A of the substrate 10 as shown in FIG. Between the plurality of functional elements 11, a division line 12 that is a virtual line that divides the plurality of functional elements 11 and indicates a position to be divided later is set. In the present embodiment, a plurality of division lines 12 are set in a lattice shape. Note that the planned division line 12 may be a line actually drawn on the substrate 10 instead of a virtual line.
Examples of the functional element 11 include an integrated circuit (IC) and a large scale integration (LSI). The plurality of functional elements 11 are partitioned by a plurality of division lines 12 and arranged in a matrix.

FIG. 2 shows a schematic cross-sectional view of a semiconductor wafer 1 having a protective member 2 attached to the surface.
In this embodiment, the sticking process which sticks the protection member 2 to the surface 1A of the semiconductor wafer 1 as shown in FIG.
The protection member 2 protects the functional element 11 formed on the surface 1A. The protective member 2 is, for example, a single layer sheet of a resin layer or a laminated sheet in which a resin layer is formed on a substrate.
The material of the resin layer used for the protective member 2 is, for example, a resin such as rubber, acrylic, silicone, polyurethane, polyurethane acrylate, polyester, polyolefin, or polyvinyl ether.

  When the protective member 2 is a single-layer sheet of a resin layer, the thickness is preferably 5 μm or more and 500 μm or less, more preferably 10 μm or more and 300 μm or less, and particularly preferably 30 μm or more and 200 μm or less. If the thickness of the sheet is too thin, grinding water may enter during grinding and the wafer surface may be contaminated. In addition, the protective sheet is not self-supporting and handling properties are reduced. On the other hand, when the thickness of the sheet is too thick, the grinding thickness accuracy of the wafer is lowered. Further, a residue derived from the resin layer may be generated on the wafer.

  Further, when the protective member 2 is a laminated sheet composed of a base material and a resin layer, the base material is not particularly limited. For example, low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, polybutene Polyolefin such as ethylene vinyl acetate copolymer, ethylene (meth) acrylic acid copolymer, ethylene copolymer such as ethylene (meth) acrylic acid ester copolymer, polyester such as polyethylene terephthalate and polyethylene naphthalate, polychlorinated A film made of vinyl, acrylic rubber, polyamide, urethane or the like is used. Moreover, as a base material, these bridge | crosslinking films are also used, for example. The above-mentioned base material may be one kind alone, or may be a composite film in which two or more kinds are combined. In addition to the above films, transparent films or opaque films colored with these can be used.

  Moreover, in order to improve adhesiveness with a resin layer, you may give a corona treatment or a primer layer in the base-material surface in which a resin layer is provided. Moreover, you may provide various layers, such as heat resistance and slipperiness, on the opposite surface to a resin layer.

  When the protective member 2 is a laminated sheet including the base material and the resin layer as described above, the thickness of the resin layer is preferably 0.5 μm to 200 μm, more preferably 1 μm to 100 μm, and particularly preferably 5 μm. It is in the range of 50 μm or less. The thickness of the substrate is preferably in the range of 5 μm to 500 μm, more preferably 10 μm to 300 μm, and particularly preferably 30 μm to 200 μm. In the case of a laminated sheet, since the self-supporting property of the sheet is maintained, the resin layer may be thinner than in the case of a single-layer sheet.

FIG. 3 is a schematic cross-sectional view illustrating a step of forming a deteriorated layer inside the semiconductor wafer 1.
In this embodiment, after the protective member 2 is attached to the front surface 1A of the semiconductor wafer 1, a pulsed laser beam having transparency to the semiconductor wafer 1 is irradiated along the planned dividing line 12 from the back surface 1B side of the semiconductor wafer 1. Then, the deteriorated layer forming step of forming the deteriorated layer 13 along the planned division line 12 (see FIG. 1) inside the substrate 10 of the semiconductor wafer 1 is performed.

The deteriorated layer forming step is performed using a laser processing apparatus 6 as shown in FIG. The laser processing apparatus 6 includes a chuck table 61 that holds a workpiece, laser beam irradiation means 62 that irradiates a workpiece held on the chuck table 61 with a pulsed laser beam, and a chuck table 61 that is not shown. An image pickup means for picking up an image of the semiconductor wafer 1 held on the substrate and a moving means for moving the chuck table 61 are provided.
The laser beam irradiation means 62 includes a pulse laser beam oscillator such as a YAG laser oscillator or a YVO ₄ laser oscillator, a repetition frequency setting means, and a condenser for condensing the oscillated pulse laser beam. This laser beam irradiation means 62 irradiates the substrate 10 of the semiconductor wafer 1 with a pulsed laser beam having transparency.

In this deteriorated layer forming step, first, the protective member 2 side of the semiconductor wafer 1 is placed on the chuck table 61.
Then, the semiconductor wafer 1 is imaged by an imaging unit (not shown), and the division schedule line 12 set in advance for the semiconductor wafer 1 is made to coincide with the actual set position in the semiconductor wafer 1 and irradiated with a pulse laser beam. Alignment work to align the power position.
After performing the alignment operation, the chuck table 61 is moved by a moving means (not shown) so that one end of one of the plurality of division planned lines 12 overlaps the irradiation position of the laser beam irradiation means 62. The relative position between the semiconductor wafer 1 and the laser beam irradiation means 62 is changed.
The chuck table 61, that is, the semiconductor wafer 1 is moved at a predetermined feeding speed while irradiating the laser beam irradiation means 62 with a pulsed laser beam from the back surface 1 </ b> B side of the semiconductor wafer 1 so as to be focused on the internal focusing point P. Thus, the position irradiated with the pulse laser beam is moved along the division line 12. When the irradiation position by the laser beam irradiation means 62 is moved from one end to the other end of the division planned line 12, the irradiation of the pulse laser beam by the laser beam irradiation means 62 is stopped and the movement of the semiconductor wafer 1 is stopped. Such pulse laser beam irradiation is performed along each of the plurality of division lines 12 set in a lattice shape.

  In this deteriorated layer forming step, the laser processing device 6 can adjust the condensing point P of the pulse laser beam to an arbitrary position inside the semiconductor wafer 1, and the deteriorated layer 13 at an arbitrary position inside the semiconductor wafer 1. Can be formed. This altered layer 13 is formed as a melt-resolidified layer and has a lower strength than the peripheral portion.

  Here, in the polishing step described later, the substrate 10 is polished from the back surface 1B side, and a part of the substrate 10 is removed. In the present embodiment, the altered layer 13 is formed on the substrate 10 in a thickness direction of the semiconductor wafer 1 (hereinafter, also simply referred to as a thickness direction) within a range that is polished and removed in a polishing process.

Polishing Step FIG. 4 is a schematic cross-sectional view illustrating a step of polishing the back surface 1B of the semiconductor wafer 1.
In the present embodiment, after the altered layer 13 is formed on the semiconductor wafer 1, a polishing step for polishing the back surface 1 </ b> B of the semiconductor wafer 1 is performed as shown in FIG. 4.
The polishing step is performed using a polishing apparatus 7 as shown in FIG. The polishing apparatus 7 includes a chuck table 71 for placing the semiconductor wafer 1 and a polishing tool 72 for polishing the semiconductor wafer 1.
The chuck table 71 is configured to be rotatable while holding the semiconductor wafer 1 placed thereon by suction means (not shown).
The polishing tool 72 includes a polishing grindstone 721 that polishes in contact with the semiconductor wafer 1, and rotates the polishing grindstone 721 in contact with the semiconductor wafer 1. As the polishing grindstone 721, for example, a material in which abrasive grains such as zirconia oxide are dispersed in a flexible member such as felt and fixed with an appropriate bond agent is used.

  In the polishing step, first, the semiconductor wafer 1 is placed on the chuck table 71 so that the protective member 2 side attached to the semiconductor wafer 1 contacts the chuck table 71 of the polishing apparatus 7. Then, while the chuck table 71 is rotated at, for example, 300 rpm, the polishing grindstone 721 is rotated at, for example, 6000 rpm, and brought into contact with the back surface 1B of the semiconductor wafer 1. Thereby, the back surface 1B of the semiconductor wafer 1 is polished. The back surface 1B of the semiconductor wafer 1 is preferably polished into a mirror surface. The thickness of the substrate 10 of the semiconductor wafer 1 after polishing is not particularly limited, but is usually about 50 μm or more and 200 μm or less.

In this polishing step, the semiconductor wafer 1 is polished from the back surface 1B side. In the polishing process of the present embodiment, the substrate 10 of the semiconductor wafer 1 is broken along the altered layer 13 by an external force from the polishing tool 72 and divided into a plurality of portions corresponding to the respective chips. At this time, the substrate 10 is cracked according to the crystal orientation of silicon which is the material of the substrate 10.
Further, the altered layer 13 is formed on the substrate 10 in the thickness direction of the semiconductor wafer 1 as long as it is polished in the polishing step. For this reason, the altered layer 13 is polished and removed by the polishing apparatus 7 together with the substrate 10. In this way, the altered layer 13 formed on the substrate 10 is removed, and the cross section of the substrate 10 that is broken in accordance with the crystal orientation of silicon is smooth. On the other hand, when the substrate 10 is cut using a blade, the cross section is rough, so that the end surface of the chip is not smooth and the end surface is likely to be chipped. For this reason, the chip is likely to crack (chipping) due to the chip formed on the end face of the chip.
The semiconductor wafer 1 is held by a protective member 2 adhered to the surface 1A. For this reason, it can suppress that each part of the board | substrate 10 divided into several parts as mentioned above is discrete.

FIG. 5 is a schematic cross-sectional view illustrating a step of forming the protective film forming layer 3 on the back surface 1B of the polished semiconductor wafer 1. FIG.
In the present embodiment, after performing the polishing step, the main formation step of forming the protective film forming layer 3 on the back surface 1B of the semiconductor wafer 1 is performed as shown in FIG. The formation process of the protective film formation layer of this embodiment is implemented by apply | coating a paste-form material to the back surface 1B of the semiconductor wafer 1 as a material of the protective film formation layer 3, for example. Moreover, the formation process of a protective film formation layer makes the sheet | seat supported by the base material so that the material of the protective film formation layer 3 can peel, arrange | positions the said sheet | seat on the back surface 1B, and then peels the base material. May be implemented.

  The protective film forming layer 3 preferably includes, for example, a thermosetting component and a binder polymer component, and is cured by a heating process described later. The thickness of the protective film forming layer 3 is preferably 3 μm or more and 100 μm or less, more preferably 10 μm or more and 60 μm or less. The storage elastic modulus at 23 ° C. after curing of the protective film forming layer 3 is preferably 100 MPa or more and 100,000 MPa or less, more preferably 1000 MPa or more and 10,000 MPa or less.

  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. In particular, in this embodiment, an epoxy resin, a phenol resin, and a mixture thereof are preferably used.

  Epoxy resins have the property of forming a three-dimensional network upon heating and forming a strong film. As such an epoxy resin, various known epoxy resins are used, but usually those having a molecular weight of about 300 to 2,000 are preferred, and in particular, a normal state liquid epoxy having a molecular weight of 300 to 500, preferably a molecular weight of 330 to 400. It is desirable to use a resin and a blended epoxy resin having a molecular weight of 400 to 2500, preferably a molecular weight of 500 to 2000, which is solid at room temperature. Moreover, the epoxy equivalent of the epoxy resin preferably used in the present embodiment is usually 50 g / eq to 5000 g / eq. Specific examples of such epoxy resins 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; Glycidyl ethers of carboxylic acids such as phthalic acid, isophthalic acid and tetrahydrophthalic acid; glycidyl type or alkyl glycidyl type epoxy resins in which active hydrogen bonded to a nitrogen atom such as aniline isocyanurate is substituted with a glycidyl group; vinylcyclohexane diepoxide; 3,4-epoxycyclohexylmethyl-3,4-dicyclohexanecarboxylate, 2- (3,4-epoxy) cyclohexyl-5,5-spiro (3,4-epoxy) cyclohexane-m-di Examples include so-called alicyclic epoxides in which an epoxy is introduced, for example, by oxidizing a carbon-carbon double bond in a molecule, such as oxane. In addition, an epoxy resin having a biphenyl skeleton, a dicyclohexadiene skeleton, or a naphthalene skeleton can be used.

  Among these, in this embodiment, bisphenol glycidyl type epoxy resin, o-cresol novolak type epoxy resin and phenol novolak type epoxy resin are preferably used. These epoxy resins can be used alone or in combination of two or more. 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.

  In the present embodiment, specific examples of the thermally activated latent epoxy resin curing agent used include various onium salts, high melting point active hydrogen compounds such as dibasic acid dihydrazide compounds, dicyandiamide, amine adduct curing agents, and imidazole compounds. Etc. 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 parts by mass or more and 20 parts by mass or less, more preferably 0.2 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the epoxy resin. Particularly preferably, it is used in a proportion of 0.3 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. Specific examples of the phenolic resin preferably used in the present embodiment include phenol novolak resin, o-cresol novolak resin, p-cresol novolak resin, t-butylphenol novolak resin, dicyclopentadiene cresol resin, polyparavinyl. A phenol resin, a bisphenol A type novolak resin, or a modified product thereof is 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 is used to give an appropriate tack to the protective film forming layer 3 and improve the operability of the sheet. The mass average molecular weight of the binder polymer is usually in the range of 50,000 to 2,000,000, preferably 100,000 to 1,500,000, particularly preferably 200,000 to 1,000,000. If the molecular weight is too low, sheet formation will be insufficient, and if it is too high, compatibility with other components will be poor, and as a result, uniform sheet formation will be hindered. As such a binder polymer, for example, an acrylic polymer, a polyester resin, a urethane resin, a silicone resin, a rubber polymer, and the like are used, and an acrylic polymer is particularly preferably used.

  Examples of the acrylic polymer include (meth) acrylic acid ester copolymers composed of structural units derived from (meth) acrylic acid ester monomers and (meth) acrylic acid derivatives. Here, the (meth) acrylic acid ester monomer is preferably a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 18 carbon atoms, such as methyl (meth) acrylate, ethyl (meth) acrylate, (meth ) Propyl acrylate, butyl (meth) acrylate, etc. are used. Examples of the (meth) acrylic acid derivative include (meth) acrylic acid, glycidyl (meth) acrylate, and hydroxyethyl (meth) acrylate.

  When a glycidyl group is introduced into an acrylic polymer by using glycidyl methacrylate as a structural unit, the compatibility with the epoxy resin as the thermosetting component described above is improved, and the glass transition temperature after curing of the protective film forming layer (Tg) is increased and heat resistance is improved. Moreover, the adhesiveness and adhesiveness to the board | substrate 10 are controllable by introduce | transducing a hydroxyl group into an acrylic polymer using hydroxyethyl acrylate etc. as a structural unit.

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

  As for the protective film formation layer 3, it is preferable that the above-mentioned thermosetting component and binder polymer component are mix | blended with the following compounding ratios. That is, the thermosetting component is preferably 50 parts by weight or more and 1500 parts by weight or less, more preferably 70 parts by weight or more and 1000 parts by weight or less, and particularly preferably 80 parts by weight or more and 800 parts by weight or less with respect to 100 parts by weight of the binder polymer component. Or less.

  Further, the protective film forming layer 3 may contain a filler. Examples of the filler include silica such as crystalline silica, fused silica, and synthetic silica, and inorganic filler such as alumina and glass balloon. By adding an inorganic filler to the protective film forming layer 3, the thermal expansion coefficient of the cured layer can be brought close to the thermal expansion coefficient of the wafer, thereby reducing the warpage of the wafer during processing. Synthetic silica is preferable as the filler, and in particular, synthetic silica of the type from which the α-ray source that causes malfunction of the semiconductor device is removed as much as possible is optimal. As the shape of the filler, any of a spherical shape, a needle shape, and an amorphous type can be used, but a spherical filler capable of closest packing is particularly preferable.

  Moreover, as a filler added to the protective film formation layer 3, the following functional fillers other than the inorganic filler mentioned above may be mix | blended. For example, for the purpose of imparting conductivity after die bonding, a conductive filler such as gold, silver, copper, nickel, aluminum, stainless steel, carbon, or ceramic, or nickel, aluminum, etc. coated with silver is added. Alternatively, for the purpose of imparting thermal conductivity, a metallic material such as gold, silver, copper, nickel, aluminum, stainless steel, silicone, germanium, or a thermal conductive material such as an alloy thereof may be added.

  Furthermore, as a filler added to the protective film formation layer 3, a coupling agent can also be added for the purpose of improving the adhesiveness / adhesion between the protective film and the substrate 10 after curing. The coupling agent can improve adhesion and adhesion without impairing the heat resistance of the protective film, and also improves water resistance (moisture heat resistance). The coupling agent is preferably a silane (silane coupling agent) because of its versatility and cost merit.

  The amount of filler added to the protective film forming layer 3 varies depending on the type of filler, but is generally 40% by mass or more and 90% by mass or less of all components forming the protective film forming layer 3. Is preferable, and it is more preferable that it is 50 mass% or more and 85 mass% or less. By setting the filler in the protective film forming layer 3 to such a blending ratio, the elastic modulus, gloss, and total light transmittance at 23 ° C. of the cured film (protective film) can be adjusted. By increasing the amount of filler, the elastic modulus at 23 ° C. of the cured coating can be increased, and a protection function for the semiconductor wafer 1 (or a chip 100 (see FIG. 10) described later) is given. On the other hand, the gloss and total light transmittance are reduced, and the recognizability of the mark printed on the surface of the protective film by the laser is improved. Further, the thermal expansion coefficient of the protective film after curing can be brought close to the thermal expansion coefficient of the wafer. Thus, it is possible to reduce the warpage of the wafer that occurs due to the difference in thermal expansion coefficient during the processing. If the wafer is warped, it is easily damaged and difficult to carry.

The protective film forming layer 3 is preferably added with a pigment or a dye. By adding a pigment or a dye to the protective film forming layer 3, it is possible to improve the recognizability of printing formed on the surface of the protective film in the marking step described later. Moreover, the elastic modulus of the protective film can be controlled to some extent by adding pigments or dyes.
Examples of such pigments include carbon black and various inorganic pigments. Also, various organic pigments such as azo, indanthrene, indophenol, phthalocyanine, indigoid, nitroso, xanthene, oxyketone and the like can be mentioned.

The amount of pigment and dye added varies depending on the type, but generally it is preferably 0.1% by mass or more and 20% by mass or less of the total components forming the protective film forming layer 3, and 0.2% by mass. % To 15% by mass is more preferable.
In addition, a crosslinking agent such as an organic polyvalent isocyanate compound, an organic polyvalent imine compound, or an organometallic chelate compound can be added to the protective film forming layer 3 in order to adjust the cohesive force before curing.

  Moreover, the protective film formation layer 3 may be colored. The protective film forming layer 3 is colored by, for example, blending a pigment, a dye or the like. If the protective film forming layer 3 is colored, the appearance can be improved.

  Further, an antistatic agent may be added to the protective film forming layer 3. By adding an antistatic agent, static electricity can be suppressed, so that the reliability of the chip is improved. Moreover, the reliability as a package improves by adding a flame retardant property by adding a phosphoric acid compound, a bromine compound, a phosphorus compound, or the like.

  When the protective film forming layer 3 includes a filler, a pigment, and a dye as described above, a clear print can be formed on the protective film by laser marking or the like. That is, in these cases, a sufficient contrast difference is obtained between the print portion and the non-print portion, and the print recognition is improved.

-Dicing sheet sticking process The cross-sectional schematic explaining the process of sticking the dicing sheet 4 to the back surface 1B side of the semiconductor wafer 1 is shown by FIG.
As shown in FIG. 6, the dicing sheet 4 includes a support base 41 and an adhesive layer 42 laminated on the support base 41 and is formed to be stretchable. The dicing sheet 4 is mounted by attaching the adhesive layer 42 to the annular ring frame 5.
In the present embodiment, as shown in FIG. 6, a dicing sheet adhering step for further adhering the dicing sheet 4 to the back surface 1B side of the semiconductor wafer 1 on which the protective film forming layer 3 is formed is performed. More specifically, the pressure-sensitive adhesive layer 42 of the dicing sheet 4 is attached to the protective film forming layer 3, and the protective film forming layer 3, the pressure-sensitive adhesive layer 42, and the support base material 41 are thus formed from the semiconductor wafer 1 side. They are stacked in the correct order.
In this way, the semiconductor wafer 1 of the present embodiment is supported by the ring frame 5 and the dicing sheet 4 as shown in FIG.

  The support substrate 41 is preferably formed of a material that is transparent to the wavelength of the laser to be used so that printing by laser marking can be performed on the protective film in a marking step described later. 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 acetate A vinyl film, an ionomer resin film, an ethylene / (meth) acrylic acid copolymer film, a polystyrene film, a polycarbonate film, a polyimide film, a fluororesin film, a liquid crystal polymer film, and the like are used. In addition, these cross-linked films and modified films by radiation / discharge or the like are also used. Moreover, these laminated films may be sufficient.

  Furthermore, when the heat resistance is taken into consideration, the support substrate 41 preferably has a high melting point. Specifically, the melting point is preferably 150 ° C. or higher, more preferably 200 ° C. or higher. When the melting point is 150 ° C. or higher, it is possible to prevent the support base material 41 from being melted and unable to maintain its shape or being fused with peripheral devices in the heating step of heat-curing the protective film forming layer 3. Specifically, for example, a polymethylpentene film, a polyethylene terephthalate film, a polyethylene naphthalate film, a polyimide film, a fluororesin film, or a liquid crystal polymer film is preferably used as the support substrate 41.

The thickness dimension of the support base material 41 is such that the support base material 41 is not torn when the support base material 41 is expanded in order to divide the semiconductor wafer 1 into chips in a dividing step described later. It is desirable that the dimensions have.
By the way, when the thickness dimension of the support base material 41 is large, it may be difficult to focus the marking laser beam used for laser marking on the protective film through the support base material 41 in the marking step described later. is there.
Therefore, when the marking process is performed as in the present embodiment, the thickness dimension of the support base material 41 preferably satisfies the following conditions. That is, the thickness dimension of the support base material 41 is a dimension having a strength capable of suppressing the above-described tearing, and further, the marking laser beam is passed over the support base material 41 over the protective film. It is preferable that the dimensions are in focus.

The pressure-sensitive adhesive layer 42 is formed of a pressure-sensitive adhesive and has adhesiveness. In the present embodiment, the pressure-sensitive adhesive layer 42 has a pressure-sensitive adhesive force that can appropriately perform peeling at the interface between the pressure-sensitive adhesive layer 42 and the protective film formed on the back surface 1B after the protective film-forming layer 3 is cured. What is necessary is just to have.
Specifically, examples of the adhesive used for the adhesive layer 42 include an acrylic adhesive, a rubber adhesive, a vinyl alkyl ether adhesive, a silicone adhesive, a polyester adhesive, a polyamide adhesive, A urethane-based adhesive, a fluorine-based adhesive, and a styrene-diene block copolymer-based adhesive can be appropriately selected and used.
Further, the pressure-sensitive adhesive layer 42 may be formed using a pressure-sensitive adhesive having a property that the adhesive force is reduced by an external stimulus such as ultraviolet rays, and thereby, at the interface between the protective film and the pressure-sensitive adhesive layer 42. Peeling can be performed appropriately. As such a pressure-sensitive adhesive that facilitates peeling between the pressure-sensitive adhesive layer 42 and the protective film, for example, an energy ray curable pressure-sensitive adhesive or a heat-expandable pressure-sensitive adhesive can be used. An adhesive can be used individually or in combination of 2 or more types. For example, the pressure-sensitive adhesive layer 42 is preferably composed of a pressure-sensitive adhesive prepared by appropriately mixing an acrylic resin, an energy beam polymerizable compound, a photopolymerization initiator, a curing agent, and the like. As the energy beam polymerizable compound, an acrylate compound, a urethane acrylate oligomer, or the like can be used. A known material can be used as the photopolymerization initiator.

  In this embodiment, since the protective film forming layer 3 is cured by heating as will be described later, the pressure-sensitive adhesive layer 42 is preferably formed of a heat-resistant pressure-sensitive adhesive. As an adhesive having heat resistance, for example, an acrylic or silicone adhesive is preferably used.

  In the present embodiment, after the treatment such as corona treatment is performed on the support base 41, the pressure-sensitive adhesive layer 42 is laminated, and the dicing sheet 4 in which the bonding strength between the support base 41 and the pressure-sensitive adhesive layer 42 is increased is used. Is preferred. The protective film formed by curing of the protective film forming layer 3 is in a state of being detachably laminated on the support base material 41 via the adhesive layer 42. Therefore, by increasing the bonding force between the support substrate 41 and the pressure-sensitive adhesive layer 42, it is possible to more appropriately perform peeling at the interface between the protective film and the pressure-sensitive adhesive layer 42 in the pickup process described later.

FIG. 7 shows a schematic cross-sectional view of the semiconductor wafer 1 after peeling off the attached protective member 2.
In the present embodiment, after the dicing sheet 4 is attached to the protective film forming layer 3 on the back surface 1B side of the semiconductor wafer 1 in the dicing sheet attaching step, the protective member 2 attached to the surface 1A of the semiconductor wafer 1 is used. A peeling process for peeling is performed.
In the peeling step, it is preferable to peel the protective member 2 from the surface 1A side of the semiconductor wafer 1 in a state where the dicing sheet 4 side is sucked and held by a suction table or the like. Since the protective film forming layer 3 before heat curing is soft, if the protective film forming layer 3 side is directly adsorbed and held by an adsorbing table or the like without adhering the dicing sheet 4, an adsorption mark is formed. Then, there is a possibility that an adsorption trace remains on the protective film due to the subsequent heating process, resulting in poor appearance. However, in this embodiment, since the dicing sheet 4 is pasted in advance and the soft protective film forming layer 3 is covered and protected, appearance defects can be suppressed.

-Heating process In this embodiment, after implementing the peeling process which peels the protection member 2, the semiconductor wafer 1 supported by the dicing sheet 4 is heated with the heating apparatus which is not shown in figure, and the protective film formation layer 3 is hardened and protected. A film (hereinafter also referred to as protective film 3A) is formed. In the heating process of the present embodiment, for example, the semiconductor wafer 1 is heated at 130 ° C. for 2 hours.

Marking Step FIG. 8 is a schematic cross-sectional view illustrating a step of applying laser marking to the protective film 3A formed on the back surface 1B of the semiconductor wafer 1.
In this embodiment, after performing a heating process, as shown in FIG. 8, the marking process which marks the protective film 3A using the laser marking apparatus 8 is implemented. In this marking process, the laser marking device 8 irradiates the protective film 3A of the semiconductor wafer 1 supported by the dicing sheet 4 with a marking laser beam from the support base material 41 side, and the protective film 3A is subjected to chip part number and manufacturing. Prints numbers, letters, marks, etc. that mean numbers.

FIG. 9 is a schematic cross-sectional view illustrating a step of dividing the semiconductor wafer 1 supported by the dicing sheet 4 and the ring frame 5 into chips 100.
In the present embodiment, after performing the marking process, as shown in FIG. 9, the dicing sheet 4 is expanded and the semiconductor wafer dividing process for dividing the semiconductor wafer 1 into the respective chips 100 is performed. In this semiconductor wafer dividing step, the semiconductor wafer 1 supported by the dicing sheet 4 is placed on the installation surface of the wafer installation unit (not shown), and the ring frame 5 is held by the ring frame holding unit (not shown). For example, it is carried out by raising the wafer setting portion by the elevating means. The outer dimension of the wafer installation part is smaller than the inner diameter dimension of the ring frame 5, and the wafer installation part passes through the inside of the ring frame 5 when raised by the lifting means.
When the wafer setting portion is raised by the lifting means, and the height of the setting surface of the wafer setting portion becomes relatively higher than the height of the ring frame 5 held by the ring frame holding portion, the dicing sheet 4 is moved as shown in FIG. As indicated by the arrows, the film is expanded in the direction orthogonal to the thickness direction and toward the outside. As a result, the semiconductor wafer 1 is divided into a plurality of chips 100. Specifically, the protective film 3 </ b> A attached to the dicing sheet 4 is extended outward according to the expansion of the dicing sheet 4. The extended protective film 3A is cut along the position where the semiconductor wafer 1 is broken in the polishing process (the position where the division planned line 12 is set). In this way, the semiconductor wafer 1 is divided into each chip 100. The divided chip 100 has a functional element 11 on the front surface and a protective film 3A on the back surface.

<Method for Manufacturing Semiconductor Device>
Hereinafter, a semiconductor device manufacturing method for manufacturing a semiconductor device by mounting a chip manufactured by the above-described chip manufacturing method on a circuit board will be described. 10 and 11 are diagrams schematically showing a cross section of each member in a process corresponding to one embodiment of a method for manufacturing a semiconductor device.
Pickup Process FIG. 10 is a schematic cross-sectional view illustrating a process of taking out each chip 100 supported by the dicing sheet 4 after the semiconductor wafer 1 is divided.
In the present embodiment, after performing the semiconductor wafer dividing step, as shown in FIG. 10, a picking-up step for taking out the singulated chips 100 is performed.
The pickup process is performed by taking out the chip 100 by a general-purpose means such as a collet.

Attachment Process FIG. 11 is a schematic cross-sectional view for explaining a process of attaching the extracted chip 100 to the circuit board 9.
A bump electrode 11A is provided on the surface of the chip 100 opposite to the surface on which the protective film 3A is provided, as shown in FIG. In addition, although the functional element 11 is also provided on the surface on which the bump electrode 11A is provided, the functional element 11 is omitted in FIG.
As shown in FIG. 11, the circuit board 9 has a substrate electrode 91 on the surface.
The bump electrode 11A of the chip 100 and the substrate electrode 91 of the circuit board 9 are electrically connected.
In the present embodiment, an attachment process for attaching the chip 100 taken out by the pickup process to the circuit board 9 is performed. The attachment process of the chip 100 of this embodiment is performed by a flip chip method. The process shown below is performed. A predetermined amount of bonding material 80 is provided on the substrate electrode 91 of the circuit board 9. As the bonding material 80, for example, solder, an anisotropic conductive film (ACF), an anisotropic conductive adhesive (ACA), or an anisotropic conductive paste (ACP) can be applied. Next, the surface of the chip 100 on which the bump electrode 11 </ b> A is provided is directed toward the substrate electrode 91, and is pressed from above the provided bonding material 80 to insert the bump electrode 11 </ b> A into the bonding material 80. At that time, the bonding material 80 also reaches the periphery of the chip 100. Next, the chip 100 is heated and pressed for a predetermined time toward the circuit board 9 by the thermocompression bonding head of the mounting apparatus to perform thermocompression bonding. Thereafter, the fillet 81 is formed between the chip 100 and the circuit board 9 or at the periphery of the chip 100 by curing the bonding material 80. Examples of the mounting method using the flip chip method include an ESC (Epoxy Encapsulated Solder Connection) method, a C4 (Controlled Collapse Chip Connection) method, and an ultrasonic flip chip method.

The chip manufacturing method according to the present embodiment described above has the following effects.
In this embodiment, it sets between the functional elements 11 from the back surface 1B side of the semiconductor wafer 1 to which the protective member 2 is attached, and the attaching step of the protective member to which the protective member 2 is attached to the front surface 1A of the semiconductor wafer 1. Laser beam irradiation is performed along the planned division line 12 to form a deteriorated layer 13 in the semiconductor wafer 1, a polishing step for polishing the back surface 1 </ b> B of the semiconductor wafer 1, and a deteriorated layer 13 is formed. Forming a protective film forming layer 3 on the back surface 1B side of the formed semiconductor wafer 1, and attaching a dicing sheet 4 to the back surface 1B side of the semiconductor wafer 1 on which the protective film forming layer 3 is formed The protective film forming layer 3 is heated by heating the semiconductor wafer 1 on which the protective film forming layer 3 is formed by heating the dicing sheet attaching process, the protective member peeling process for peeling the protective member 2, and the protective film forming layer 3. Form A heating step, the supporting substrate 41 is expanded, and the semiconductor wafer dividing step for dividing the wafer into a plurality of chips along the dividing lines 12 are sequentially carried out.
According to this embodiment, after forming the protective film formation layer 3 which has thermosetting in the back surface 1B, the dicing sheet 4 containing the support base material 41 is arrange | positioned at the back surface 1B side. Then, after the protective member 2 is peeled off, the protective film forming layer 3 is heated and cured to form the protective film 3A.
Thus, in the chip manufacturing method in which the semiconductor wafer 1 is divided into a plurality of chips 100 using the stealth dicing method, the protective film 3A is formed on the back surface of the chip 100 using the thermosetting protective film forming layer 3. can do.
In particular, when the flip chip mounting method is adopted as in the case of the chip 100, the protective film 3A having a light shielding property and an antistatic property is formed on the back side of the chip 100, so that the chip 100 can be made incident by light or charged. While suppressing deterioration, the intensity | strength of the chip | tip 100 can be improved.

In the present embodiment, the deteriorated layer forming step is performed by forming the deteriorated layer 13 in a state where the protective member 2 is disposed on the surface 1A of the semiconductor wafer 1. Next, through the polishing process, the protective film forming layer forming process and the dicing sheet adhering process are performed while the protective member 2 is disposed, and the protective film forming layer 3 and the dicing sheet 4 are sequentially laminated on the semiconductor wafer 1. . Thereafter, the protective member peeling process is performed to peel off the protective member 2.
According to this, the semiconductor wafer 1 is a member that supports the entire semiconductor wafer 1 on at least one of the front surface 1A side and the back surface 1B side, that is, the protective member 2 and the support base, with the altered layer 13 formed. Any one of the materials 41 is arranged. Therefore, the semiconductor wafer 1 that has been easily divided due to the formation of the deteriorated layer 13 is divided unintentionally at the formation position of the deteriorated layer 13 and is chip-shaped before the marking process or before mounting on the circuit board 9. It can prevent falling apart.

Moreover, according to this embodiment, a pulse laser beam can be incident from the back surface 1B side where the functional element 11 of the semiconductor wafer 1 is not formed.
Here, in the deteriorated layer forming step, when a pulse laser beam is incident from the surface 1A side of the semiconductor wafer 1, the transmission of the pulse laser beam is hindered by the metal wiring or the like included in the functional element 11 formed on the surface 1A. There is a possibility that the pulsed laser beam cannot be condensed at a desired position inside. As a result, defective formation of the deteriorated layer 13 occurs, and the semiconductor wafer 1 may not be divided along the division line 12.
On the other hand, in the chip manufacturing method of this embodiment, since the pulse laser beam can be incident from the back surface 1B side as described above, it is possible to appropriately form the altered layer 13 along the planned dividing line 12. it can.

In the present embodiment, with the protective member 2 disposed on the semiconductor wafer 1, the altered layer forming step, the polishing step, the protective film forming layer forming step, and the dicing sheet attaching step are performed, and the back surface 1 </ b> B of the semiconductor wafer 1. The protective film forming layer 3 and the support base material 41 are sequentially laminated. Then, after performing the peeling process of a protective member and peeling off the protective member 2, a heating process is implemented and the protective film formation layer 3 is heat-hardened.
Here, if the protective member 2 that protects the surface 1A when the semiconductor wafer 1 is polished has a heat resistance and can be easily peeled off after heating, the protective film forming layer 3 is heated to heat and cure. After the process, the protective member 2 can be peeled off. However, the protection member 2 having both the performance to protect the surface 1A and the heat resistance when polishing the semiconductor wafer 1 is not generally known.
In this embodiment, since a heating process is performed after peeling off the protection member 2, the material generally used as the protection member 2 can be used, and the increase in cost can be suppressed.

  By the way, the protective film formation layer 3 before heat-curing is soft, and is easy to have a crack and a mark. However, in the present embodiment, the protective film forming layer 3 is covered with the dicing sheet 4 when the protective member peeling step and the heating step are performed. Therefore, for example, it is possible to prevent the adsorption device or the like from coming into contact with the surface of the protective film forming layer 3 to leave a contact mark on the protective film forming layer 3 and to deteriorate the appearance of the protective film 3A after heat curing. Further, the surface on which the protective film 3A is provided is easily visible even after being mounted on the circuit board 9. According to the present embodiment, it is possible to prevent the appearance defect of the chip 100 due to scratches and contact marks formed on the protective film 3A.

In the present embodiment, the protection film forming layer 3 is heated and cured at the time of manufacturing the chip, and each process (pickup process, attachment process) of the semiconductor device manufacturing method is performed on the chip 100 on which the protective film 3A is formed on the back surface. ). Thereby, the chip 100 can be protected by the protective film 3A in each step of the semiconductor manufacturing method.
As described above, the protective film forming layer 3 before heating is soft. For this reason, when a pick-up process and an attachment process are implemented before the protective film formation layer 3 is heat-hardened, an object contacts the back surface side of the chip | tip 100, and the surface of the protective film formation layer 3 before heat-hardening becomes rough. Or may be scraped, or foreign matter may adhere to the surface of the protective film forming layer 3.
On the other hand, in this embodiment, since the pick-up process and the attachment process are performed after the protective film forming layer 3 is heat-cured, the surface of the protective film forming layer 3 may be roughened or scraped. It is possible to prevent foreign matter from adhering to the surface.

In the present embodiment, a marking process for marking the heat-cured protective film 3A is performed.
Here, in the chip 100 employing the flip chip mounting, the functional element 11 is mounted toward the circuit board 9, and the protective film 3 </ b> A is located on the surface opposite to the circuit board 9. Therefore, various information such as the product number and the serial number of each chip 100 can be easily confirmed from the upper surface of the circuit board 9.
Further, in the present embodiment, the protective film 3A contains a pigment or a dye, so that a sufficient contrast difference can be obtained between the printed portion and the non-printed portion, thereby improving the recognition of printing. Can do.

In the present embodiment, the polishing step is performed after the deteriorated layer forming step. Thereby, the substrate 10 of the semiconductor wafer 1 is broken along the altered layer 13 in the polishing process. At this time, the substrate 10 is cracked according to the crystal orientation of silicon which is the material of the substrate 10. Thereafter, in the polishing step, the altered layer 13 is polished together with a part of the substrate 10 and removed. For this reason, the cross-section of the substrate 10 is a smooth surface formed according to the crystal orientation, with hardly any altered layer 13 remaining. Therefore, the end surface of the chip 100 can be smoothed.
Here, when the end surface is not smooth and there is a chip, the chip 100 may crack from the chip. In this embodiment, since the end face can be made smooth, the occurrence of such cracks can be prevented and the chip strength can be improved.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the following description, the same members, configurations, means and the like as those already described are denoted by the same reference numerals, and description thereof is simplified or omitted.

FIG. 12 is a schematic cross-sectional view schematically showing a laminated sheet adhering step for adhering the laminated sheet 4 </ b> A to the back surface 1 </ b> B side of the semiconductor wafer 1.
In the method for manufacturing a semiconductor chip according to the second embodiment, the adhesive layer 42 and the protective film forming layer 3 are laminated in advance on the support base 41 after performing the attaching step, the altered layer forming step, and the polishing step. This is different from the first embodiment in which the protective film forming layer 3 and the dicing sheet 4 are sequentially applied in that the laminated sheet 4A is attached to the back surface 1B of the semiconductor wafer 1.
The laminated sheet 4 </ b> A corresponds to the multilayer film sheet of the present invention, and as shown in FIG. 12, an adhesive layer 42 and a protective film forming layer 3 are sequentially laminated on a support base 41. The pressure-sensitive adhesive layer 42 of the laminated sheet 4 </ b> A is attached to the ring frame 5, and the laminated sheet 4 </ b> A is attached to the ring frame 5.

In the present embodiment, the laminated sheet 4A is attached to the back surface 1B side of the semiconductor wafer 1 after the protective member attaching step, the altered layer forming step, and the polishing step are performed. At this time, the protective film forming layer 3 is attached so as to cover the back surface 1 </ b> B side of the semiconductor wafer 1.
Thereafter, similarly to the first embodiment, the protective member peeling step, the heating step, the marking step, and the semiconductor wafer dividing step are performed to divide the semiconductor wafer 1 into the respective chips 100. The divided chip 100 is taken out in the pickup process and mounted on the circuit board 9 in the attachment process.

  In the chip manufacturing method of the second embodiment, in addition to the same effects as those of the first embodiment, the support base material 41 and the protective film forming layer 3 can be simultaneously disposed on the back surface 1B of the semiconductor wafer 1. Therefore, the number of steps can be reduced, and the chip manufacturing method can be simplified.

[Modification]
The present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

  In each of the above embodiments, when the marking step is performed, the embodiment using the support base material made of a material that can be printed by laser marking has been described, but the present invention is not limited to such an embodiment. In the case where the marking step is not performed, a support base material of another material can be used. For example, a metal base material such as a metal foil or a metal plate, a resin foam film, fine paper, impregnated paper, glassine paper, coated paper, non-woven paper, or the like can be used.

  In each of the above-described embodiments, the polishing step is performed after performing the deteriorated layer forming step. However, the present invention is not limited to this, and the deteriorated layer forming step may be performed after performing the polishing step. When the polishing step is performed first, the deteriorated layer forming step can be performed in a state where the surface of the back surface 1B is smoother. Thereby, it can prevent more reliably that it injects from the back surface 1B, and a laser beam is irregularly reflected in the back surface 1B.

  In each of the embodiments described above, the case where the substrate 10 of the semiconductor wafer 1 is broken in the polishing process has been described, but the present invention is not limited to this. That is, the substrate 10 is not broken in the polishing process, and may be divided together with the protective film 3A when the support base material 41 is expanded in the semiconductor wafer dividing process. As described above, when the deteriorated layer forming step is performed after the polishing step, the substrate 10 is divided into chips together with the protective film 3A in the dividing step.

  In each of the above embodiments, the altered layer 13 is formed in the range of the substrate 10 that is removed in the polishing step in the thickness direction. However, the present invention is not limited to this, and may be formed at any position in the thickness direction. Good.

  In each said embodiment, although the heating process was implemented after the peeling process of a protection member, this invention is not limited to this, You may implement before the peeling process of a protection member. In addition, when performing the peeling process of a protection member before a heating process, the material which does not have the heat resistance which can endure a heating process as mentioned above can be used as a protection member.

  Moreover, in each said embodiment, although the heating process was implemented before the marking process, this invention is not limited to this, You may implement after a marking process and before a pick-up process. Further, if no marking is required on the chip, the marking process may not be performed.

In each of the above embodiments, the heating step is performed in the chip manufacturing method, and the protective film forming layer 3 is cured to manufacture the chip 100 on which the protective film 3A is formed. However, the present invention is not limited to this.
For example, in the chip manufacturing method, the semiconductor wafer dividing step may be performed without performing the heating step, and the chip having the protective film forming layer formed on the back surface may be manufactured.
In this case, when the chip is thermocompression bonded to the circuit board in the mounting step of the semiconductor device manufacturing method, the protective film forming layer may be simultaneously cured to form the protective film.
Moreover, you may harden a protective film formation layer by implementing a heating process after an attachment process, and may form a protective film. Note that the heating step is simply a process performed for heat-curing the protective film forming layer, or when a gap is generated between the pressure-bonded circuit board and the chip, the gap is made thermosetting. The sealing process etc. which seal with this sealing resin can be illustrated.
Thereby, the heating process of heat-curing the protective film forming layer can be omitted from the chip manufacturing method, and the process can be simplified in the chip manufacturing method. As described above, when the protective film forming layer is also heat-cured at the same time in an existing process such as an attachment process, the process should be simplified in the whole chip manufacturing method and semiconductor device manufacturing method. Can do.
Further, since the heating process is not performed in the chip manufacturing method, it is not necessary to use a heat-resistant material as the support substrate 41 of the dicing sheet 4 and the laminated sheet 4A, and a material that can be selected as the support substrate. The number of types can be increased. Thereby, for example, an inexpensive material having no heat resistance can be selected, and the manufacturing cost of the chip can be reduced.
In addition, as described above, the surface of the protective film forming layer is roughened by performing the heating process before the pickup process, and performing the pickup process and the attaching process after the protective film forming layer is heat-cured, It can suppress that a foreign material adheres to the surface of a protective film formation layer.

In each said embodiment, although the protective film formation layer contained a thermosetting component, this invention is not restricted to this, Furthermore, an energy-beam curable component may be included.
Here, the energy ray-curable component can be exemplified by a compound that is polymerized and cured when irradiated with energy rays such as ultraviolet rays and electron beams. This compound has at least one polymerizable double bond in the molecule, and usually has a molecular weight of about 100 to 30,000, preferably about 300 to 10,000. Specific examples of such energy beam polymerization type compounds include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, and 1,4. -Use of butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, oligoester acrylate, polyester-type or polyether-type urethane acrylate oligomer, polyester acrylate, polyether acrylate, epoxy-modified acrylate, etc. Can do. Among these, it is preferable to use an ultraviolet curable resin, and specifically, it is particularly preferable to use an oligoester acrylate, a urethane acrylate oligomer, or the like.

  Further, by mixing a photopolymerization initiator into the energy ray curable component, the polymerization curing time and the amount of light irradiation can be reduced. Specific examples of such photopolymerization initiators include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, methyl benzoin benzoate, benzoin dimethyl ketal, Examples include 2,4-diethylthioxanthone, α-hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, tetramethyl thiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, β-chloranthraquinone, and the like. The photopolymerization initiator is desirably used at a ratio of about 1.5 to 4.5 parts by mass, preferably about 2.4 to 3.8 parts by mass, with respect to 100 parts by mass of the energy ray curable component.

Moreover, when mix | blending both a thermosetting component and an energy-beam curable component in the protective film formation layer 3 as a sclerosing | hardenable component, a thermosetting component and an energy-beam curable component are total, and it is 100 mass parts of binder polymer components. On the other hand, it is preferably used in a proportion of 50 to 1500 parts by mass, more preferably 70 to 1000 parts by mass, particularly preferably 80 to 800 parts by mass. In this case, the mass ratio of the thermosetting component to the energy ray curable component (thermosetting component / energy ray curable component) is preferably 55/45 to 97/3, more preferably 60/40 to 95. / 5, particularly preferably 70/30 to 90/10.
In such a ratio, when the thermosetting component and / or the energy ray curable component and the binder polymer component are blended, an appropriate tack is exhibited before curing, and the protective film forming layer can be stably formed. Moreover, after hardening, the protective film excellent in film strength is obtained.

DESCRIPTION OF SYMBOLS 1 ... Semiconductor wafer 1A ... Front surface 1B ... Back surface 11 ... Functional element 12 ... Dividing schedule line 13 ... Alteration layer 2 ... Protection member 3 ... Protection film formation layer 3A ... Protection film 4 ... Dicing sheet 41 ... Support base material 4A ... Laminate sheet 100 ... chip

Claims (6)

Attaching a protective member to the surface of the wafer on which a plurality of functional elements are formed;
From the back side of the wafer to which the protective member is adhered, a laser beam having transparency to the wafer is irradiated along the scheduled division line set between the functional elements, and the inside of the wafer is altered. Forming a layer;
Polishing the back surface of the wafer to which the protective member is attached;
Forming a protective film forming layer having thermosetting on the back side of the wafer on which the altered layer is formed;
A step of adhering a dicing sheet comprising a support substrate and an adhesive layer on the back side of the wafer on which the protective film forming layer is formed;
After pasting the dicing sheet, a step of peeling the protective member stuck to the surface of the wafer;
Dividing the wafer into a plurality of chips along the division line.
A method of manufacturing a chip characterized by the above. Attaching a protective member to the surface of the wafer on which a plurality of functional elements are formed;
From the back side of the wafer to which the protective member is adhered, a laser beam having transparency to the wafer is irradiated along the scheduled division line set between the functional elements, and the inside of the wafer is altered. Forming a layer;
Polishing the back surface of the wafer to which the protective member is attached;
A multilayer substrate sheet comprising a supporting substrate, a pressure-sensitive adhesive layer laminated on the supporting substrate, and a protective film-forming layer laminated on the pressure-sensitive adhesive layer and having thermosetting properties, and the protective film-forming layer is the wafer A step of adhering to the back side of the wafer on which the altered layer is formed, so as to be formed on the back side of
After pasting the multilayer film sheet, the step of peeling the protective member stuck to the surface of the wafer;
Dividing the wafer into a plurality of chips along the division line.
A method of manufacturing a chip characterized by the above. In the manufacturing method of the chip according to claim 1 or 2,
Heating the wafer on which the protective film forming layer and the dicing sheet are laminated, or the wafer on which the multilayer film sheet is adhered, curing the protective film forming layer, and forming a protective film; A method for manufacturing a chip, characterized in that: In the manufacturing method of the chip according to claim 3,
The method of manufacturing a chip, wherein the step of heating the wafer is performed after the step of peeling the protective member. In the manufacturing method of the chip according to claim 3 or claim 4,
A method of manufacturing a chip, wherein a step of irradiating the protective film with a marking laser beam from the side of the supporting substrate and marking the protective film is performed. In the manufacturing method of the chip according to any one of claims 1 to 5,
A method for manufacturing a chip, comprising performing a step of polishing a back surface of the wafer after the step of forming the deteriorated layer inside the wafer, and removing the deteriorated layer.

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