JP2010219432A - Wafer processing tape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer processing tape that suppresses a chip leap in a dicing step and occurrence of an error such that an adjacent chip is lifted together in a picking-up step. <P>SOLUTION: The wafer processing tape 10 has a pressure-sensitive adhesive film 12 comprising a base film 12a and a pressure-sensitive adhesive layer 12b, and an adhesive layer 13 laminated on the pressure-sensitive adhesive film 12. The pressure-sensitive adhesive layer 12b has an elastic coefficient of 0.05 to 0.6 MPa at 80°C, and the adhesive layer 13 has an elastic coefficient of 0.1 to 1 MPa at 80°C. Fusion of the adhesive layer 13 and the pressure-sensitive adhesive film 12 in dicing is suppressed to suppress formation of cutting remainders of the adhesive layer, pressure-sensitive adhesive layer, etc. During the dicing, a decrease in adhesive power of the pressure-sensitive adhesive layer is suppressed to suppress peeling on an interface between the pressure-sensitive adhesive layer and the adhesive layer, and a decrease in adhesive power of the adhesive layer is suppressed to suppress peeling on an interface between a semiconductor chip with the adhesive layer in the form of an individual piece and the adhesive layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wafer processing tape used in both a dicing step of cutting a semiconductor wafer into semiconductor elements (chips) and a die bonding step of bonding the cut chips to a lead frame or another chip.

  In a semiconductor device manufacturing process, a semiconductor wafer is cut (diced) into chips, a cut chip is picked up, and a die bonding (mount) process in which the picked-up chip is bonded to a lead frame, a package substrate, or the like. Is implemented.

A dicing die-bonding sheet in which a pressure-sensitive adhesive layer and an adhesive layer are formed in this order on a base material is known as a wafer processing tape used in the manufacturing process of the semiconductor device (see, for example, Patent Document 1). ).
The adhesive layer used in such a dicing die bond sheet contains a lot of low molecular weight substances such as an epoxy resin, and is used for a general dicing tape (tape having an adhesive layer formed on a base material). Compared with the pressure-sensitive adhesive layer, it tends to be soft and inferior in machinability. Therefore, during dicing, there is a lot of beard-like cutting scraps and burrs on the adhesive layer of the semiconductor wafer, which tends to cause pick-up failures in the pick-up process after dicing, and in the assembly process of semiconductor devices such as IC. However, there is a problem in that defective bonding of the chip tends to occur or defective products such as ICs are generated.

  Therefore, as a conventional technique for solving such a problem, a wafer processing tape in which an intermediate resin layer, an adhesive layer, and an adhesive layer are laminated in this order on a substrate, the intermediate resin layer at 80 ° C. A semiconductor processing tape is known in which the storage elastic modulus is larger than the storage elastic modulus at 80 ° C. of the pressure-sensitive adhesive layer (see, for example, Patent Document 2).

JP 2005-303275 A JP 2006-49509 A

However, in the wafer processing tape described in Patent Document 2, the adhesive layer and the adhesive layer are likely to melt during dicing depending on the elastic modulus of the adhesive layer and the adhesive layer. An uncut (burr) occurs in the pressure-sensitive adhesive layer, etc., and an error (double die error) occurs when the adjacent chip (semiconductor chip with an adhesive layer separated into pieces) is picked up at the time of pickup due to the effect of the uncut There was a problem. Also, depending on the elastic modulus of the adhesive layer and adhesive layer, the holding force to the semiconductor wafer during dicing (adhesive force that the adhesive layer holds the adhesive layer and the semiconductor chip in which the adhesive layer is singulated is held In other words, the semiconductor wafer is peeled off to cause chip fly.
Accordingly, an object of the present invention is to provide a wafer processing tape that can suppress the occurrence of chip jumping in the dicing process and can suppress the occurrence of double die error in which adjacent chips are lifted together in the pickup process.

In order to solve the above problems, a wafer processing tape according to the invention of claim 1 is a wafer processing tape in which a base film, an adhesive layer, and an adhesive layer are formed in this order, The elastic modulus at 80 ° C. of the pressure-sensitive adhesive layer is 0.05 to 0.6 MPa, and the elastic modulus at 80 ° C. of the adhesive layer is 0.1 to 1 MPa.
According to the present invention, it is possible to suppress the occurrence of uncut portions in the adhesive layer, the pressure-sensitive adhesive layer, and the like during dicing, thereby suppressing the occurrence of double die errors in which adjacent chips are lifted together due to the influence of the uncut portions during pickup. can do. In addition, during dicing, the pressure-sensitive adhesive layer retains the adhesive layer and the decrease in the adhesive strength is suppressed, peeling at the interface between the pressure-sensitive adhesive layer and the adhesive layer is suppressed, and the adhesive layer holds the semiconductor wafer. Decrease in the adhesive force is suppressed, and peeling at the interface between the separated semiconductor chip with an adhesive layer and the adhesive layer is suppressed. For this reason, generation | occurrence | production of the chip | tip jump at the time of dicing can be suppressed.

  The wafer processing tape according to claim 2 has a value obtained by dividing the elastic modulus at 80 ° C. of the adhesive layer by the elastic modulus at 80 ° C. of the pressure-sensitive adhesive layer is 0.5 to 3. It is characterized by that. According to this invention, it is possible to reliably pick up the separated semiconductor chip with an adhesive layer with a smaller force in the pickup process.

  A wafer processing tape according to a third aspect of the invention is characterized in that the pressure-sensitive adhesive layer contains at least a carbon-carbon double bond-containing acrylic copolymer.

  According to the present invention, it is possible to suppress the occurrence of chip jumping in the dicing process, and to suppress the occurrence of double die errors in which adjacent chips are lifted together by the influence of the cutting residue of the adhesive layer, the adhesive layer, etc. in the pickup process. can do.

It is sectional drawing which shows the tape for wafer processing which concerns on embodiment of this invention. It is the figure which bonded the semiconductor wafer on the tape for wafer processing. It is a figure for demonstrating a dicing process. It is a figure for demonstrating an expanding process. It is a figure for demonstrating a pick-up process.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view showing a wafer processing tape 10 according to an embodiment. The wafer processing tape 10 includes an adhesive film 12 including a base film 12 a and an adhesive layer 12 b formed thereon, and an adhesive layer 13 laminated on the adhesive film 12. Thus, in the wafer processing tape 10, the base film 12a, the pressure-sensitive adhesive layer 12b, and the adhesive layer 13 are formed in this order.
The pressure-sensitive adhesive layer 12b may be composed of a single pressure-sensitive adhesive layer, or may be composed of a laminate of two or more pressure-sensitive adhesive layers. FIG. 1 shows a state where a release liner 11 is provided on the wafer processing tape 10 in order to protect the adhesive layer 13.

  The pressure-sensitive adhesive film 12 and the adhesive layer 13 may be cut (precut) into a predetermined shape in advance in accordance with the use process and the apparatus. The tape for wafer processing of the present invention includes a form cut for each semiconductor wafer and a form obtained by winding a plurality of long sheets formed on a roll.

The wafer processing tape 10 according to the present embodiment is characterized in that it has the following configuration.
The elastic modulus at 80 ° C. of the pressure-sensitive adhesive layer 12b is 0.05 to 0.6 MPa, and the elastic modulus at 80 ° C. of the adhesive layer 13 is 0.1 to 1 MPa.
More preferably, the elastic modulus of the pressure-sensitive adhesive layer 12b at 80 ° C. is 0.2 to 0.5 MPa, and the elastic modulus of the adhesive layer 13 at 80 ° C. Is 0.2 to 0.8 MPa.

When the elastic modulus at 80 ° C. (hereinafter referred to as elastic modulus B) of the pressure-sensitive adhesive layer is 0.05 MPa or less (see Comparative Example 1 in Table 3 below), the adhesive layer 13 and the pressure-sensitive adhesive layer 12b are melted during dicing. Is likely to occur. For this reason, a double die error occurs in which an uncut portion is generated in the adhesive layer 13, the adhesive layer 12b, etc., and the adjacent chip (separated semiconductor chip 2 with an adhesive layer) is lifted together at the time of pickup due to the influence of the uncut portion Frequently occurs.
On the other hand, when the elastic modulus B is 0.6 MPa or more (see Comparative Example 2 in Table 3 below), the pressure (pressure-sensitive adhesive force) that the pressure-sensitive adhesive layer 12b holds the adhesive layer 13 during dicing decreases. Peeling occurs at the interface between the layer 12b and the adhesive layer 13, and chip fly occurs.

When the elastic modulus at 80 ° C. of the adhesive layer 13 (hereinafter referred to as the elastic modulus A) is 0.1 MPa or less (see Comparative Examples 1 and 3 in Table 3 below), the adhesive layer 13 and the pressure-sensitive adhesive layer during dicing 12b is likely to melt. For this reason, uncut portions are generated in the adhesive layer 13, the pressure-sensitive adhesive layer 12b, and the like, and double die errors frequently occur during pickup due to the influence of the uncut portions.
On the other hand, when the elastic modulus A is 1 MPa or more (see Comparative Example 4 in Table 3 below), the force with which the adhesive layer 13 holds the semiconductor wafer 1 during dicing is reduced, so that the semiconductor with an adhesive layer separated into pieces is obtained. Peeling occurs at the interface between the chip 2 and the adhesive layer 13, and chip fly occurs.

  The value obtained by dividing the elastic modulus A of the adhesive layer 13 at 80 ° C. by the elastic modulus B of the pressure-sensitive adhesive layer 12b at 80 ° C. (ratio A / B of elastic modulus) is 0.5 to 3. preferable. When the elastic modulus ratio A / B is 0.5 or less, a large force is required to pick up the cut semiconductor chip 2. On the other hand, when the ratio A / B of the elastic modulus is 3 or more, the force for holding the semiconductor wafer 1 during dicing decreases, so that the interface between the separated semiconductor chip 2 with the adhesive layer and the adhesive layer 13 is separated. Further, peeling occurs at the interface between the adhesive layer 13 and the pressure-sensitive adhesive layer 12b, and chip fly occurs.

Hereafter, each component of the tape 10 for wafer processing of this embodiment is demonstrated in detail.
(Adhesive layer)
The adhesive layer 13 is peeled off from the adhesive film 12 and attached to the semiconductor chip 2 when the semiconductor chip 2 is picked up after the semiconductor wafer 1 or the like is bonded and diced, and the semiconductor chip 2 is attached to the substrate or lead frame. It is used as an adhesive when being fixed to. Therefore, the adhesive layer 13 has a releasability that can be peeled off from the adhesive film 12 while remaining attached to the separated semiconductor chip 2 in the pick-up process. In order to bond and fix the semiconductor chip 2 to a substrate or a lead frame, it has sufficient bonding reliability.

  The adhesive layer 13 is obtained by forming a film of an adhesive in advance. For example, a known polyimide resin, polyamide resin, polyetherimide resin, polyamideimide resin, polyester resin, polyesterimide resin, phenoxy used for the adhesive is used. Resins, polysulfone resins, polyether sulfone resins, polyphenylene sulfide resins, polyether ketone resins, chlorinated polypropylene resins, acrylic resins, polyurethane resins, epoxy resins, polyacrylamide resins, melamine resins, and the like and mixtures thereof can be used. Moreover, in order to reinforce the adhesive force with respect to a chip | tip or a lead frame, it is desirable to add a silane coupling agent or a titanium coupling agent to the said material and its mixture as an additive.

  In order to increase the elastic modulus A at 80 ° C. of the adhesive layer 13, it is effective to increase the high molecular weight component (polymer (3) described later) and / or increase the silica. In order to reduce the elastic modulus A, it is effective to increase the low molecular weight component (epoxy resin).

  The thickness of the adhesive layer 13 is not particularly limited, but is usually preferably about 5 to 100 μm. The adhesive layer 13 may be laminated on the entire surface of the pressure-sensitive adhesive layer 12b of the pressure-sensitive adhesive film 12. However, the adhesive layer 13 that has been cut (pre-cut) into a shape corresponding to the semiconductor wafer 1 to be bonded in advance is adhered. You may laminate | stack on a part of agent layer 12b. When the adhesive layer 13 cut into a shape corresponding to the semiconductor wafer 1 is laminated, as shown in FIG. 2, the adhesive layer 13 is provided at a portion where the semiconductor wafer 1 is bonded, and a ring frame 20 for dicing is provided. There is no adhesive layer 13 in the portion where the adhesive film is bonded, and only the adhesive layer 12b of the adhesive film 12 exists. In general, since the adhesive layer 13 is difficult to peel off from the adherend, the ring frame 20 can be attached to the adhesive film 12 by using the pre-cut adhesive layer 13, and the ring is peeled off when the sheet is peeled after use. The effect that it is hard to produce the adhesive residue on a flame | frame is acquired.

(Adhesive film)
The adhesive film 12 has a sufficient adhesive force so that the semiconductor wafer 1 does not peel off when the semiconductor wafer 1 is diced, and can be easily peeled off from the adhesive layer 13 when the semiconductor chip 2 is picked up after dicing. It has such a low adhesive strength. In the present embodiment, as the adhesive film 12, as shown in FIG. 1, a substrate film 12a provided with an adhesive layer 12b is used.

  The base film 12a of the adhesive film 12 can be used without particular limitation as long as it is a conventionally known one. However, in the present embodiment, as the adhesive layer 12b, as described later, energy curable is used. Since a radiation curable material is used among these materials, a material having radiation transparency is used.

  For example, as a material of the base film 12a, polyethylene, polypropylene, ethylene-propylene copolymer, polybutene-1, poly-4-methylpentene-1, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer , Homopolymers or copolymers of α-olefins such as ethylene-methyl acrylate copolymer, ethylene-acrylic acid copolymer, ionomer or mixtures thereof, polyurethane, styrene-ethylene-butene copolymer or pentene Listed are thermoplastic elastomers such as copolymers, polyamide-polyol copolymers, and mixtures thereof. Moreover, the base film 12a may be a mixture of two or more materials selected from these groups, or may be a single layer or a multilayer. The thickness of the base film 12a is not particularly limited and may be set appropriately, but is preferably 50 to 200 μm.

  In the present embodiment, the pressure-sensitive adhesive layer 12b is cured by irradiating the pressure-sensitive adhesive film 12 with radiation such as ultraviolet rays, and the pressure-sensitive adhesive layer 12b is easily peeled off from the pressure-sensitive adhesive layer 13. For the resin 12b, known chlorinated polypropylene resins, acrylic resins, polyester resins, polyurethane resins, epoxy resins, addition-reactive organopolysiloxane resins, silicon acrylate resins, ethylene-vinyl acetate copolymer used for adhesives Copolymers, ethylene-ethyl acrylate copolymers, ethylene-methyl acrylate copolymers, ethylene-acrylic acid copolymers, various elastomers such as polyisoprene, styrene / butadiene copolymers and hydrogenated products thereof, and mixtures thereof It is preferable to prepare a pressure-sensitive adhesive by appropriately blending a radiation polymerizable compoundVarious surfactants and surface smoothing agents may be added. The thickness of the pressure-sensitive adhesive layer is not particularly limited and may be appropriately set, but is preferably 5 to 30 μm. The pressure-sensitive adhesive layer provided on the wafer processing tape of the present invention contains a copolymer of an alkyl (meth) acrylate and a polar group-containing monomer (hereinafter, this copolymer is also referred to as an “acrylic compound”), and acrylic. It is preferable to use an acrylic pressure-sensitive adhesive mainly composed of a base compound and a curing agent described later. Examples of the alkyl (meth) acrylate include pentyl acrylate, n-butyl acrylate, isobutyl acrylate, ethyl acrylate, methyl acrylate, hexyl acrylate, n-octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, decyl acrylate, Or methacrylates similar to these, or functional groups having acrylic acid, methacrylic acid, cinnamic acid, itaconic acid, fumaric acid, phthalic acid, 2-hydroxyalkyl acrylates, 2-hydroxyalkyl methacrylates, glycol monoacrylates , Glycol monomethacrylates, N-methylolacrylamide, N-methylolmethacrylamide, allyl alcohol, N-alkylamino ester Acrylates, N-alkylaminoethyl methacrylates, acrylamides, methacrylamides, maleic anhydride, itaconic anhydride, fumaric anhydride, phthalic anhydride, glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, vinyl acetate, styrene, Examples include acrylonitrile and vinyl alcohol.

  One or a plurality of acrylic compounds may be used, and a low molecular compound may be allowed to coexist for the purpose of improving compatibility and various performances. The acrylic compound is preferably one having photopolymerizability, and as a method for imparting photopolymerizability, a method of directly introducing a photopolymerizable carbon-carbon double bond into the acrylic compound, Examples thereof include a method of adding a compound having a photopolymerizable carbon-carbon double bond that can be mixed with an acrylic compound.

  As a method of directly introducing a photopolymerizable carbon-carbon double bond into the acrylic compound, a method having a functional group in the side chain of the acrylic compound and a photopolymerization with a functional group capable of undergoing addition reaction therewith It can be obtained by adding a compound having a reactive carbon-carbon double bond to the acrylic compound. As the compound having a functional group capable of addition reaction with the acrylic compound and a photopolymerizable carbon-carbon double bond, when the side chain to be subjected to the addition reaction is a carboxyl group or an acid anhydride, glycidyl ( When (meth) acrylate etc. are mentioned and the side chain which is the object of addition reaction is an epoxy group, (meth) acrylic acid etc. are mentioned, and when the side chain which is the object of addition reaction is a hydroxyl group , 2-isocyanate alkyl (meth) acrylate and the like.

  The compound having a photopolymerizable carbon-carbon double bond that can be mixed with the acrylic compound is a compound having two or more photopolymerizable carbon-carbon double bonds in the molecule, and the weight average molecular weight is from 100. Compounds in the range of 30000 can be used. Specific examples of such compounds include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4-butylene. Examples include glycol diacrylate, 1,6 hexanediol diacrylate, polyethylene glycol diacrylate, and oligoester acrylate. In addition, urethane acrylate compounds can also be used. The urethane acrylate compound includes a polyol compound such as a polyester type or a polyether type, and a polyvalent isocyanate compound (for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diene). A terminal isocyanate urethane prepolymer obtained by reacting isocyanate, 1,4-xylylene diisocyanate, diphenylmethane 4,4-diisocyanate, etc.) with an acrylate or methacrylate having a hydroxyl group (for example, 2-hydroxyethyl) Acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, polyethylene glycol acrylate, polyethylene glycol methacrylate, etc.) Obtained by.

  The hydroxyl value of the copolymer of the alkyl (meth) acrylate and the polar group-containing monomer is not particularly limited, but the hydroxyl value is preferably 150 mgKOH / g or less, more preferably 50 mgKOH / g or less. At this time, it is preferable to obtain a copolymer having the desired hydroxyl value by adjusting the copolymerization rate of the polar group (for example, hydroxyl group) -containing monomer. Depending on the type of monomer used, for example, the polar group-containing monomer It is preferable to obtain a copolymer having a desired hydroxyl value with a copolymerization ratio (number of moles of polar group-containing monomer / number of moles of all monomers constituting the copolymer) of 0 mol% or more and less than 60 mol%. The copolymer may contain other monomers as long as the effects of the present invention are not hindered. The molecular weight of the copolymer of the alkyl (meth) acrylate and the polar group-containing monomer is not particularly limited and can be appropriately determined depending on the type of the monomer used. For example, the weight average molecular weight is 200,000 to 1,500,000. preferable.

  In addition, what added the compound which has a photopolymerizable carbon-carbon double bond which can be mixed with the said acrylic compound has a low molecular weight, a large temperature change, and the elasticity modulus B in 80 degreeC of the adhesive layer 12b is 80 degreeC. Since there is a tendency to significantly decrease, it is preferable to use a material in which a photopolymerizable carbon-carbon double bond is directly introduced into the acrylic compound.

  When using a photopolymerization initiator, for example, isopropyl benzoin ether, isobutyl benzoin ether, benzophenone, Michler's ketone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, benzyldimethyl ketal, α-hydroxycyclohexyl phenyl ketone, 2-hydroxymethylphenyl Propane or the like can be used. The blending amount of these photopolymerization initiators is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the acrylic copolymer.

In order to increase the elastic modulus B at 80 ° C. of the pressure-sensitive adhesive layer 12b, the crosslinking density of the polymer (acrylic polymer (1) or (2) described later) is increased and / or the glass transition temperature Tg of the polymer. It is effective to increase the value. To lower the elastic modulus B, it is effective to perform the reverse.
In order to increase the crosslinking density of the polymer, it is effective to increase the amount of the curing agent, and it is preferable that the curing agent is 1 to 15 parts by mass with respect to 100 parts by mass of the polymer. More preferably, a hardening | curing agent shall be 4-8 mass parts with respect to 100 mass parts of polymers. The glass transition temperature Tg is preferably -80 to 0 ° C, more preferably -40 to -10 ° C.
In order to increase the glass transition temperature (Tg), it may be synthesized using a monomer having a high Tg during the production of the polymer. To lower the Tg, the reverse is effective.

  When the amount of the curing agent is small and the Tg is low, the pickup property is deteriorated. On the other hand, when the amount of the curing agent is large and Tg is high, the adhesive layer 12b of the adhesive film 12 cannot be bonded to the adhesive layer 13 before dicing due to a decrease in holding power at room temperature. ) The pressure-sensitive adhesive layer 12b cannot be attached to the ring frame 20, and (3) problems such as chip skipping during dicing occur.

(How to use wafer processing tape)
In the semiconductor device manufacturing process, the wafer processing tape 10 is used as follows. FIG. 2 shows a state in which the semiconductor wafer 1 and the ring frame 20 are bonded to the wafer processing tape 10. First, as shown in FIG. 2, the adhesive layer 12 b of the adhesive film 12 is attached to the ring frame 20, and the semiconductor wafer 1 is attached to the adhesive layer 13. There is no limitation on the order of these attachments, and the adhesive layer 12b of the adhesive film 12 may be attached to the ring frame 20 after the semiconductor wafer 1 is attached to the adhesive layer 13. Further, the adhesion of the adhesive film 12 to the ring frame 20 and the adhesion of the semiconductor wafer 1 to the adhesive layer 13 may be performed simultaneously.

  Then, a dicing process of the semiconductor wafer 1 is performed (FIG. 3), and then a process of irradiating the adhesive film 12 with energy rays, for example, ultraviolet rays. Specifically, since the semiconductor wafer 1 and the adhesive layer 13 are diced by the dicing blade 21, the wafer processing tape 10 is sucked and supported from the adhesive film 12 surface side by the suction stage 22. Then, the dicing blade 21 cuts the semiconductor wafer 1 and the adhesive layer 13 into units of two semiconductor chips, and then irradiates energy rays from the lower surface side of the adhesive film 12. By this energy ray irradiation, the pressure-sensitive adhesive layer 12b is cured to reduce its adhesive strength. In addition, it may replace with energy ray irradiation and may reduce the adhesive force of the adhesive layer 12b of the adhesive film 12 by external stimuli, such as a heating. When the pressure-sensitive adhesive layer 12b is formed by laminating two or more pressure-sensitive adhesive layers, one or all of the pressure-sensitive adhesive layers are cured by irradiation with energy rays, and one of the pressure-sensitive adhesive layers. Or you may reduce the adhesive force of all the layers.

  Thereafter, as shown in FIG. 4, an expanding process is performed in which the adhesive film 12 holding the diced semiconductor chip 2 and the adhesive layer 13 is stretched in the circumferential direction of the ring frame. Specifically, the hollow cylindrical push-up member 30 is raised from the lower surface side of the pressure-sensitive adhesive film 12 with respect to the pressure-sensitive adhesive film 12 in a state where the plurality of diced semiconductor chips 2 and the adhesive layer 13 are held. The film 12 is stretched in the circumferential direction of the ring frame 20. The expansion process widens the distance between the semiconductor chips 2 and improves the recognizability of the semiconductor chips 2 by a CCD camera or the like, and the re-adhesion between the semiconductor chips caused by the contact between the adjacent semiconductor chips 2 at the time of pickup. Can be prevented.

  After performing the expanding process, as shown in FIG. 5, the pick-up process which picks up the semiconductor chip 2 is implemented with the adhesive film 12 being expanded. Specifically, the semiconductor chip 2 is pushed up by the pins 31 from the lower surface side of the adhesive film 12 and the semiconductor chip 2 is separated from the upper surface side of the adhesive film 12 by adsorbing the semiconductor chip 2 by the adsorption jig 32. Is picked up together with the adhesive layer 13.

  Then, after performing the pickup process, the die bonding process is performed. Specifically, the semiconductor chip 2 is bonded to a lead frame, a package substrate, or the like by the adhesive layer 13 picked up together with the semiconductor chip 2 in the pickup process.

(Example)
Next, examples of the present invention will be described, but the present invention is not limited to these examples.

(Base film 12a)
As the base film 12a, an elastomer-added polypropylene having a thickness of 100 μm was used.

(Preparation of adhesive layer composition)
The pressure-sensitive adhesive layer compositions 1A to 1F are acrylic radiation-curable pressure-sensitive adhesive compositions having the configurations shown in Table 1 below.

<Adhesive layer composition 1A>
As shown in Table 1, the pressure-sensitive adhesive layer composition 1A comprises 100 parts by mass of an acrylic polymer (1), 100 parts by mass of urethane acrylate, 3 parts by mass of a curing agent (isocyanate compound), a photopolymerization initiator (1 3-hydroxy-cyclohexyl-phenyl-ketone) was dissolved in an organic solvent and mixed to obtain. The acrylic polymer (1) is an acrylic copolymer having no double bond having a weight average molecular weight (Mw) of 600,000 and a glass transition temperature Tg of −60 ° C.

<Adhesive layer composition 1B>
The pressure-sensitive adhesive layer composition 1B comprises 100 parts by mass of an acrylic polymer (2), 10 parts by mass of a curing agent (isocyanate compound), and 3 parts by mass of a photopolymerization initiator (1-hydroxy-cyclohexyl-phenyl-ketone). It was obtained by dissolving in an organic solvent and mixing. The acrylic polymer (2) is a carbon-carbon double bond-containing acrylic copolymer having a weight average molecular weight (Mw) of 300,000 and a glass transition temperature Tg of −35 ° C.

<Adhesive layer composition 1C>
Adhesive layer composition 1C dissolves 100 parts by mass of acrylic polymer (1), 60 parts by mass of urethane acrylate, 5 parts by mass of the curing agent, and 3 parts by mass of the photopolymerization initiator in an organic solvent. Obtained by mixing.

<Adhesive layer composition 1D>
The pressure-sensitive adhesive layer composition 1D was obtained by dissolving 100 parts by mass of the acrylic polymer (2), 3 parts by mass of the curing agent, and 3 parts by mass of the photopolymerization initiator in an organic solvent and mixing them.

<Adhesive layer composition 1E>
The pressure-sensitive adhesive layer composition 1E was obtained by dissolving 100 parts by mass of the acrylic polymer (2), 7 parts by mass of the curing agent, and 3 parts by mass of the photopolymerization initiator in an organic solvent and mixing them.

<Adhesive layer composition 1F>
The pressure-sensitive adhesive layer composition 1F was obtained by dissolving and mixing 100 parts by mass of the acrylic polymer (2), 5 parts by mass of the curing agent, and 3 parts by mass of the photopolymerization initiator in an organic solvent.

  The pressure-sensitive adhesive layer compositions 1A to 1F shown in Table 1 were applied to the base film 12a so as to have a dry film thickness of 10 μm, and dried at 110 ° C. for 3 minutes to prepare a pressure-sensitive adhesive film 12.

(Preparation of adhesive layer composition)
As the adhesive layer compositions 2A to 2E, coating solutions for the adhesive layer 13 were prepared by blending the components shown in Table 2 below.

<Adhesive layer composition 2A>
As shown in Table 2, the adhesive layer composition 2A includes 100 parts by mass of the acrylic polymer (3), 60 parts by mass of the epoxy resin, 55 parts by mass of the curing agent (1), and 1. 5 parts by mass was dissolved in an organic solvent and mixed to obtain. The acrylic polymer (3) is an acrylic copolymer having a weight average molecular weight (Mw) of 850,000 and a glass transition temperature Tg of 15 ° C. The epoxy resin is an o-cresol novolac type epoxy resin having an epoxy equivalent of 210 to 230. The curing agent (1) is a novolac type phenol resin having a hydroxyl group equivalent of 160 to 190. The curing agent (2) is an imidazole compound (2-phenyl 4,5-dihydroxymethylimidazole).

<Adhesive layer composition 2B>
The adhesive layer composition 2A comprises 100 parts by mass of the acrylic polymer (3), 18 parts by mass of the epoxy resin, 15 parts by mass of the curing agent (1), and 1 part by mass of the curing agent (2). It was obtained by dissolving in an organic solvent and mixing.

<Adhesive layer composition 2C>
Adhesive layer composition 2C comprises acrylic polymer (3) 100 parts by mass, epoxy resin 5 parts by mass, curing agent (1) 3 parts by mass, curing agent (2) 0.5 parts by mass, silica 70 parts by mass of filler was dissolved in an organic solvent and mixed. The silica filler is a spherical synthetic silica filler having an average particle diameter of 2 μm.

<Adhesive layer composition 2D>
As shown in Table 2, the adhesive layer composition 2D includes 100 parts by mass of the acrylic polymer (3), 18 parts by mass of the epoxy resin, 15 parts by mass of the curing agent (1), and the curing agent (2) 1 A part by mass and 80 parts by mass of the silica filler were dissolved in an organic solvent and mixed.

<Adhesive layer composition 2E>
Adhesive layer composition 2E comprises acrylic polymer (3) 100 parts by mass, epoxy resin 18 parts by mass, curing agent (1) 15 parts by mass, curing agent (2) 1 part by mass, and silica filler 50 parts by mass. Parts were dissolved in an organic solvent and mixed.

The adhesive layer compositions 2A to 2E are applied on a release-treated polyethylene terephthalate (PET) film (release liner), dried by heating at 130 ° C. for 3 minutes, and in a B-stage state with a film thickness of 20 μm An adhesive film was prepared.
The produced pressure-sensitive adhesive film 12 and adhesive film were cut into circles having a diameter of 370 mm and 320 mm, respectively, and the pressure-sensitive adhesive layer 12b of the pressure-sensitive adhesive film 12 and the adhesive layer 13 of the adhesive film were bonded together. Finally, the PET film of the adhesive film is peeled from the adhesive layer 13, and the wafer processing tape according to Comparative Examples 1 to 4 shown in Table 3 below and the wafers according to Examples 1 to 6 shown in Table 4 below. A processing tape 10 was obtained.

Table 3 shows combinations of the pressure-sensitive adhesive layer composition and the adhesive layer composition constituting the wafer processing tapes according to Comparative Examples 1 to 4. Further, the elastic modulus B at 80 ° C. of the pressure-sensitive adhesive layer in each of Comparative Examples 1 to 4, the elastic modulus A at 80 ° C. of the adhesive layer, the chip jump (%), and the pickup success rate are shown.
Table 4 shows combinations of the pressure-sensitive adhesive layer composition and the adhesive layer composition constituting the wafer processing tape 10 according to Examples 1 to 6. Further, the elastic modulus B at 80 ° C. of the adhesive layer 12b in each of Examples 1 to 6, the elastic modulus A at 80 ° C. of the adhesive layer 13, the chip jump (%), and the pickup success rate (%) are shown. It is.

<Elastic modulus measurement>
The elastic modulus B at 80 ° C. of the pressure-sensitive adhesive layer 12b and the elastic modulus A at 80 ° C. of the adhesive layer 13 were measured using a viscoelasticity meter (trade name: ARES, manufactured by Rheometric Science). In this measurement, two separator films (PET) coated with a pressure-sensitive adhesive (pressure-sensitive adhesive layer composition) 10 μm were prepared, bonded together with pressure-sensitive adhesives, and the separator film on one side was peeled off. Prepare a film with 10 µm of adhesive applied to the film, repeat the process of pasting together with the adhesive, laminate until the thickness is 2 mm, and finally peel off the remaining separator film to obtain a laminate of 8 mmφ A punched adhesive layer sample was used.

Similarly, two adhesives (20 μm) coated with an adhesive (adhesive layer composition) are prepared on a separator film (PET), bonded together with the adhesive, and the separator film on one side is peeled off. A laminate obtained by preparing a separator film coated with 20 μm of adhesive, laminating the adhesive film to each other by repeating the process of laminating the adhesive together, and peeling off the remaining separator film. Was punched out to 8 mmφ and used as a sample of the adhesive layer.
About the sample of the obtained adhesive layer and the sample of the adhesive layer, the measurement was started from 0 ° C., and the dynamic viscoelasticity was measured at a temperature rising rate of 10 ° C./min and a frequency of 1 Hz. The storage elastic modulus G ′ was defined as the elastic modulus B of the pressure-sensitive adhesive layer 12b at 80 ° C. and the elastic modulus A of the adhesive layer 13 at 80 ° C.

(Measurement method of chip skipping and pickup success rate)
The wafer processing tapes of Comparative Examples 1 to 4 and Examples 1 to 6 were heated and bonded at 70 ° C. to a silicon wafer (semiconductor wafer) having a thickness of 75 μm and a diameter of 200 mm, and this was dicing apparatus (DFD6340 manufactured by Disco). Placed on top. Next, the semiconductor wafer is fixed on a dicing apparatus and diced to 5 × 5 mm at a speed of 100 mm / second, and then the adhesive layer is irradiated with ultraviolet rays of 500 mJ / cm ² by an air-cooled high-pressure mercury lamp. Pick-up was performed using an apparatus (manufactured by NEC Machinery). Chip jumping was evaluated with the probability% (/ 100 chip) that the semiconductor chip 2 (chip) flew during dicing, and the pick-up property was evaluated with the probability% (/ 100) that the chip could be picked up by the pickup die bonder. The pin push-up conditions at this time were a pin push-up height of 0.5 mm and a push-up speed of 5000 μm / sec.

In Comparative Example 1, the elastic modulus B is 0.034 smaller than the lower limit value of the above range 0.05 to 0.6 MPa that defines the elastic modulus B, and the elastic modulus A is the above range 0.1 that defines the elastic modulus A. It is 0.091 which is smaller than the lower limit of ˜1 MPa. Thus, in Comparative Example 1, since both the elastic modulus A and the elastic modulus B are low, the pickup success rate is low.
In Comparative Example 2, the elastic modulus B is 0.65, which is larger than the upper limit of the above range of 0.05 to 0.6 MPa, and since the elastic modulus B is high, 9 (%) chip fly occurs during dicing.
In Comparative Example 3, the elastic modulus A is 0.91 smaller than the lower limit of the above range of 0.1 to 1 MPa, and the elastic modulus A is low, so the pickup success rate is low.
In Comparative Example 4, the elastic modulus A is 1.4, which is larger than the upper limit of the above range of 0.1 to 1 MPa, and since the elastic modulus A is high, 12 (%) chip fly occurs during dicing.
In Table 3, when the elastic modulus B and the elastic modulus A are out of the above ranges of 0.05 to 0.6 MPa and 0.1 to 1 MPa, x is indicated, and when not, ○ is indicated. .

In each of Examples 1 to 6, the elastic modulus B is in the above range of 0.05 to 0.6 MPa, and the elastic modulus A is also in the above range of 0.1 to 1 MPa. The pick-up success rate is as high as 96%.
In Table 4, it is indicated by ◯ that the elastic modulus B is in the range of 0.05 to 0.6 MPa and the elastic modulus A is in the range of 0.1 to 1 MPa. Further, the elastic modulus B is in the range of 0.2 to 0.5 MPa, which is more preferable for defining the elastic modulus B, and the elastic modulus A is more preferably in the range of 0.2 to 0 which defines the elastic modulus A. ◎ indicates that it is within 8 MPa.

実施例Ａ〜Ｃは、弾性率の比Ａ／Ｂを０．５〜３の範囲内にあるため、ピン突き上げ高さが０．３ｍｍであっても、ピックアップ成功率が９０〜９５％と高い。 Next, for Examples 1 to 6, the elastic modulus ratio A / B is in the range of 0.5 to 3 in Table 5 below. Examples A to C (Example A = Example above) 2, Example B = Example 3 above, Example C = Example 6 above), and the ratio A / B outside the range of 0.5-3 is shown in Table 5 below as Comparative Examples AC (Comparative Example A = Example 1 above, Comparative Example B = Example 4 above, Comparative Example C = Example 5 above) For each of Examples A to C and Comparative Examples A to C, the pick-up success rate when the pin push-up height is 0.3 mm and the push-up speed is 5000 μm / sec is shown.

In Examples A to C, since the elastic modulus ratio A / B is in the range of 0.5 to 3, even if the pin push-up height is 0.3 mm, the pickup success rate is as high as 90 to 95%. .

The wafer processing tape 10 according to the present embodiment has the following operational effects.
In the wafer processing tape 10, the elastic modulus B at 80 ° C. of the pressure-sensitive adhesive layer 12 b is in the range of 0.05 to 0.6 MPa, and the elastic modulus A at 80 ° C. of the adhesive layer 13 is 0.1 to 0.1. It is in the range of 1 MPa.

(1) Since the elastic modulus B is larger than 0.05 MPa, melting of the adhesive layer 13 and the pressure-sensitive adhesive layer 12b is suppressed at the time of dicing, and the occurrence of uncut residue in the adhesive layer 13 and the pressure-sensitive adhesive layer 12b is suppressed. Is done. Thereby, it is possible to suppress the occurrence of a double die error in which adjacent chips (separated semiconductor chips 2 with an adhesive layer) are lifted together by the influence of the uncut portion during pick-up.
(2) Since the elastic modulus B is smaller than 0.6 MPa, the pressure-sensitive adhesive layer 12b is prevented from holding down the adhesive layer 13 at the time of dicing, and the interface between the adhesive layer 12b and the adhesive layer 13 is suppressed. Peeling is suppressed. Thereby, generation | occurrence | production of the chip | tip jump at the time of dicing can be suppressed.
(3) Since the elastic modulus A is larger than 0.1 MPa, melting of the adhesive layer 13 and the pressure-sensitive adhesive layer 12b is suppressed at the time of dicing, and the occurrence of uncut residue in the adhesive layer 13 and the pressure-sensitive adhesive layer 12b is suppressed. Is done. Thereby, at the time of pick-up, it is possible to suppress the occurrence of a double die error in which adjacent chips are lifted together by the influence of the uncut portion.
(4) Since the elastic modulus A is smaller than 1 MPa, a decrease in the adhesive force of the adhesive layer 13 holding the semiconductor wafer 1 during dicing is suppressed, and the separated semiconductor chip 2 with the adhesive layer and the adhesive layer 13 are separated. Peeling at the interface is suppressed. Thereby, generation | occurrence | production of the chip | tip jump at the time of dicing can be suppressed.

In this way, the occurrence of uncut residues in the adhesive layer, pressure-sensitive adhesive layer, etc. during dicing is suppressed, so the occurrence of double die errors in which adjacent chips are lifted together due to the effects of uncut portions during pickup is suppressed. can do. Moreover, at the time of dicing, the fall of the adhesive force of the adhesive layer 12b is suppressed, peeling at the interface of the adhesive layer 12b and the adhesive layer 13 is suppressed, and the reduction of the adhesive force of the adhesive layer 13 is also suppressed. Thus, peeling at the interface between the separated semiconductor chip 2 with the adhesive layer and the adhesive layer 13 is suppressed. For this reason, generation | occurrence | production of the chip | tip jump at the time of dicing can be suppressed.
Therefore, in the dicing process, it is possible to suppress peeling at the interface between the pressure-sensitive adhesive layer and the adhesive layer and peeling at the interface between the semiconductor chip and the adhesive layer, thereby causing chip skipping. It is possible to suppress the occurrence of a double die error in which adjacent chips are lifted together by the influence of the uncut portion of the layer, the adhesive layer, and the like.

Further, by making the elastic modulus B within the range of 0.2 to 0.5 MPa and the elastic modulus A within the range of 0.2 to 0.8 MPa, the semiconductor with the adhesive layer separated in the pickup process The chip 2 can be reliably picked up with a smaller force.
In addition, by setting the elastic modulus ratio A / B within the range of 0.5 to 3, the separated semiconductor chip 2 with the adhesive layer can be reliably picked up with a smaller force in the pickup process. .

In the wafer processing tape 10 according to the above embodiment, when the pressure-sensitive adhesive layer 12b is formed by laminating two or more pressure-sensitive adhesive layers, the elastic modulus B at 80 ° C. of the pressure-sensitive adhesive layer is one layer of the pressure-sensitive adhesive layer. In the same manner as in the case of comprising viscoelasticity, a viscoelasticity meter (manufactured by Rheometric Science, trade name: ARES) is used.
In other words, in this measurement, after two separators (PET) coated with 10 μm of pressure-sensitive adhesive (adhesive layer composition) were prepared, bonded together with pressure-sensitive adhesives, and the separator film was peeled off Further, two separators coated with 10 μm of pressure-sensitive adhesive were prepared, and the process of bonding the pressure-sensitive adhesives together was repeated until the thickness became 2 mm. A sample of the pressure-sensitive adhesive layer is punched out. About the sample of the obtained adhesive layer, the measurement was started from 0 ° C., the dynamic viscoelasticity was measured at a heating rate of 10 ° C./min, and a frequency of 1 Hz, respectively, and the storage elastic modulus G ′ when reaching 80 ° C. Is the elastic modulus B at 80 ° C. of the pressure-sensitive adhesive layer 12b.

1: Semiconductor wafer 2: Semiconductor chip (semiconductor element)
10: Wafer processing tape 12: Adhesive film 12a: Base film 12b: Adhesive layer 13: Adhesive layer

Claims (3)

A wafer processing tape in which a base film, an adhesive layer, and an adhesive layer are formed in this order,
The wafer processing tape, wherein the pressure-sensitive adhesive layer has an elastic modulus at 80 ° C. of 0.05 to 0.6 MPa, and the adhesive layer has an elastic modulus at 80 ° C. of 0.1 to 1 MPa. .   2. The semiconductor processing tape according to claim 1, wherein a value obtained by dividing an elastic modulus at 80 ° C. of the adhesive layer by an elastic modulus at 80 ° C. of the pressure-sensitive adhesive layer is 0.5 to 3. 3. .   The semiconductor processing tape according to claim 1, wherein the pressure-sensitive adhesive layer contains at least a carbon-carbon double bond-containing acrylic copolymer.

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