JP4999117B2 - Wafer processing tape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer processing tape that makes it easy to peel between a pressure-sensitive adhesive layer and an adhesive layer without thrusting a pin up in a step of picking up a semiconductor element with an adhesive layer in the form of an individual piece. <P>SOLUTION: The wafer processing tape 10 includes a pressure-sensitive adhesive film 12 comprising a base film 12a and the pressure-sensitive adhesive layer 12b formed thereupon, and the adhesive layer 13 laminated on the pressure-sensitive adhesive film 12. The pressure-sensitive adhesive layer 12b and adhesive layer 13 contain different residual solvents whose residual solvent amounts exceed 15 &mu;g/g and which have a difference in solubility of &ge;1. In the step of picking up the semiconductor chip 2 with the adhesive layer 13 in the form of the individual piece, the residual solvent of the pressure-sensitive adhesive layer 12b and the residual solvent of the adhesive layer 13 are less dissolved. In the picking-up step, the semiconductor chip 2 with the adhesive layer 13 in the form of the individual piece can be easily peeled from the pressure-sensitive adhesive layer 12b. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a wafer processing tape used in both a dicing process of cutting and separating a semiconductor wafer into semiconductor elements (chips) and a die bonding process of bonding the separated chips to a lead frame and other chips. .

  In the manufacturing process of a semiconductor device, a semiconductor wafer is cut and separated (diced) into chips, a separated chip is picked up, and a die bonding (mount) for bonding the picked up chip to a lead frame, a package substrate, or the like. A process is performed.

As a wafer processing tape used in the manufacturing process of the semiconductor device, a wafer sticking pressure-sensitive adhesive sheet in which a pressure-sensitive adhesive layer and an adhesive layer are formed in this order on a base material is known (for example, Patent Documents). 1).
However, in the wafer processing tape in which the pressure-sensitive adhesive layer and the adhesive layer are formed in this order on the base material, the time required for the pressure-sensitive adhesive layer and the adhesive layer to contact each other is inevitably between production and use. Since it becomes longer, both layers become familiar before use, and there is a problem that the pressure-sensitive adhesive layer and the adhesive layer cannot be peeled off well in the step of picking up the separated semiconductor element with the adhesive layer.

  Therefore, as a tape for wafer processing that solves such problems, the iodine value of a radiation-polymerizable compound having a carbon-carbon double bond that constitutes an adhesive layer, the hydroxyl equivalent of a phenol resin that constitutes an adhesive layer, etc. It is known that the separated semiconductor element with an adhesive layer can be easily peeled off from the pressure-sensitive adhesive layer (see, for example, Patent Document 2).

JP 2002-226996 A JP 2005-303275 A

However, in the tape for wafer processing described in Patent Document 2, when a solvent is used for the pressure-sensitive adhesive layer and the adhesive layer, a slight remaining solvent diffuses and adhesion between the pressure-sensitive adhesive layer and the adhesive layer increases. In some cases, the pressure-sensitive adhesive layer and the adhesive layer cannot be easily peeled off. Further, at the time of picking up, in order to facilitate peeling between the pressure-sensitive adhesive layer and the adhesive layer, the chip is pushed up from the lower side of the pressure-sensitive adhesive layer with a pin, but in recent years, the chip becomes thinner. If the tip is thin and the push-up force is increased, the tip will be damaged. Therefore, it is easier to peel off the adhesive layer and the adhesive layer without increasing the pin push-up force. There is a need to.
Accordingly, an object of the present invention is to facilitate the separation between the adhesive layer and the adhesive layer without increasing the pin push-up force in the process of picking up the separated semiconductor element with the adhesive layer. The object is to provide a wafer processing tape.

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 pressure-sensitive adhesive layer and the adhesive layer are residual solvents having a residual solvent amount exceeding 15 μg / g, and are characterized by containing different residual solvents having a difference in solubility parameter of 1 or more.
Here, the “residual solvent” refers to solvents that remain in the pressure-sensitive adhesive layer and the adhesive layer, respectively. When forming the pressure-sensitive adhesive layer on the base film, after preparing the pressure-sensitive adhesive layer composition using a solvent, the thickness after drying of the pressure-sensitive adhesive layer composition on the base film is a predetermined value. The pressure-sensitive adhesive layer composition is applied and dried. The solvent remaining in the pressure-sensitive adhesive layer thus formed is the residual solvent of the pressure-sensitive adhesive layer. Moreover, when forming an adhesive layer on an adhesive layer, after preparing an adhesive layer composition using a solvent, the thickness after drying of the adhesive layer composition on the adhesive layer is predetermined. The adhesive layer composition is applied so as to have a value of and dried. The solvent remaining in the adhesive layer thus formed is the residual solvent of the adhesive layer.
In the tape for wafer processing in which both the pressure-sensitive adhesive layer and the adhesive layer contain such residual solvent, as described above, in the step of picking up the separated semiconductor element (semiconductor chip) with the adhesive layer, the pressure-sensitive adhesive Since each solvent of the layer and the adhesive layer is diffused to increase the adhesiveness between the adhesive layer and the adhesive layer, there is a problem that the adhesive layer and the adhesive layer may not be easily peeled off.

  The invention described in claim 1 has been made to solve such a problem, and is effectively applied to a wafer processing tape containing a residual solvent in both an adhesive layer and an adhesive layer. According to the present invention, the pressure-sensitive adhesive layer and the adhesive layer are residual solvents having a residual solvent amount exceeding 15 μg / g and containing different residual solvents having a difference in solubility parameter (SP value) of 1 or more. Therefore, the melting of the residual solvent of the pressure-sensitive adhesive layer and the residual solvent of the adhesive layer is reduced, and the adhesiveness between the pressure-sensitive adhesive layer and the adhesive layer is lowered. Therefore, the semiconductor element can be easily peeled from the pressure-sensitive adhesive layer in the step of picking up the separated semiconductor element with an adhesive layer (pickup step), and stable pickup is possible. Thereby, the pickup defect rate can be reduced. If the residual solvent having an SP value difference smaller than 1 is more than 15 μg / g, the residual solvent in the pressure-sensitive adhesive layer and the residual solvent in the adhesive layer increase in melting, and the pressure-sensitive adhesive layer and the adhesive layer Adhesion increases. Therefore, the semiconductor element with an adhesive layer separated in the pickup process may not be easily peeled from the pressure-sensitive adhesive layer.

The tape for wafer processing according to another aspect of the present invention is characterized in that the adhesive layer contains two or more solvents.
The tape for wafer processing according to another aspect of the present invention is characterized in that the pressure-sensitive adhesive layer contains two or more solvents.

  According to the present invention, there is provided a wafer processing tape that facilitates peeling between an adhesive layer and an adhesive layer without picking up a pin in a process of picking up an individual semiconductor element with an adhesive layer. Can be realized.

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 pressure-sensitive adhesive layer 12b and the adhesive layer 13 are residual solvents having a residual solvent amount exceeding 15 μg / g, and contain different residual solvents having a difference in solubility parameter (SP value) of 1 or more.
The solvent used for the pressure-sensitive adhesive layer 12b and the adhesive layer 13 has a difference in solubility parameter of the residual solvent between the pressure-sensitive adhesive layer 12b and the adhesive layer 13 of 1 or more, and constitutes the pressure-sensitive adhesive layer 12b and the adhesive layer 13. Although it will not specifically limit if the solubility of each resin is good, From a viewpoint of easy manufacture, it is preferable that it is a low boiling point (about 160 degrees C or less).

The SP value used in the present invention is a value calculated by the following equation.
SP value = (ΣΔe _i / ΣΔv _i ) ^0.5
Here, Δe _i and Δv _i indicate the evaporation energy (cal / mol) and the molar volume (cm ³ / mol) of atoms and atomic groups, and each value is calculated using the method of Fedors (D.W. Van Krevelen, "Properties of Polymers, Second, Completely Revised Ed." Elsevier Scientific Publishing, 1976, p138-140). The calculation of ΣΔe _i and ΣΔv _i for the copolymer A / B is a value calculated by the following equation.
ΣΔe _{i A / B} = ΣΔe _{i A} · (1−x _B ) + ΣΔe _{i B} · x _B
ΣΔv _{i A / B} = ΣΔv _{i A} · (1−x _B ) + ΣΔv _{i B} · x _B
Here, Δe _{i A} , Δe _{i B} , Δv _{i A} , and Δv _{i B} indicate the evaporation energy and molar volume of atoms and atomic groups of the A component and the B component, respectively, and x _B It is the mole fraction of the B component in the coalescence.

In addition, there is a limitation on the selectable solvent (solvent for polymerization) due to solubility when the polymers contained in the pressure-sensitive adhesive layer 12b and the adhesive layer 13 are synthesized, and the pressure-sensitive adhesive layer 12b and the adhesive layer When the difference in solubility parameter of 13 residual solvents is smaller than 1, the residual solvent amount is preferably 15 μg / g or less. If the residual solvent amount is 15 μg / g or less, there is almost no influence on the pickup characteristics. In order to reduce the residual solvent amount to 15 μg / g or less, for example, the adhesive layer 12b and the adhesive layer 13 are formed at the time of manufacturing the adhesive layer 12b and the adhesive layer 13 by using a solvent having a low boiling point. The solvent may be volatilized by the heat applied to apply the composition to the film and dry it. In such a case, it is preferable to separately add a solvent in which the difference in solubility parameter of the residual solvent is 1 or more. In that case, the amount of solvent added is preferably about 20 to 60% of the total amount of solvent.
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.

  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 difficult to produce adhesive residue on the frame is obtained.

(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 radiation-polymerizable compound includes, for example, a low molecular weight compound having at least two photopolymerizable carbon-carbon double bonds in a molecule that can be three-dimensional networked by light irradiation, and a photopolymerizable carbon-carbon double bond group. A polymer or oligomer having a substituent is used. Specifically, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4-butylene glycol diacrylate, 1,6 hexanediol diacrylate For example, acrylate, polyethylene glycol diacrylate, oligoester acrylate, silicon acrylate, etc., acrylic acid, copolymers of various acrylic esters, and the like are applicable.

  In addition to the above acrylate compounds, urethane acrylate oligomers can also be used. The urethane acrylate oligomer 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 reaction. The pressure-sensitive adhesive layer 12b may be a mixture of two or more selected from the above resins.

  The resin of the pressure-sensitive adhesive layer 12b is appropriately blended with an acrylic pressure-sensitive adhesive, a photopolymerization initiator, a curing agent, etc., in addition to a radiation-polymerizable compound that cures the pressure-sensitive adhesive layer 12b by irradiating the pressure-sensitive adhesive film 12 with radiation. Thus, the pressure-sensitive adhesive layer 12b can also be prepared.

  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.

(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 irradiation of an energy ray 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 energy ray irradiation, 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.

  Next, examples of the present invention will be described, but the present invention is not limited to these examples. First, after preparing the base film 12a and the adhesive layer compositions 1A to 1E described later, the adhesive layer compositions 1A to 1E have a thickness of 20 μm after drying on the base film 12a. The layer compositions 1A to 1E were applied and dried at 110 ° C. for 2 minutes to prepare an adhesive film 12. Next, adhesive layer compositions 2A to 2D to be described later are prepared, and the release liner 11 made of a polyethylene-terephthalate film obtained by releasing the adhesive layer compositions 2A to 2D has a thickness after drying of 20 μm. The adhesive layer compositions 2A to 2D were applied to the substrate and dried at 150 ° C. for 5 minutes to form an adhesive layer 13 on the release liner 11. And after cutting the adhesive film 12 and the adhesive layer 13 into the shape shown in FIG. 2, the adhesive layer 13 is bonded to the adhesive layer 12b side of the adhesive film 12, and Examples 1-4 and Comparative Examples 1- 3 was created. Below, the preparation methods of base film 12a, adhesive layer composition 1A-1E, and adhesive layer composition 2A-2D are shown.

(Preparation of base film 12a)
An ethylene-vinyl acetate copolymer film having a thickness of 100 μm was prepared as the base film 12a. For example, commercially available resin beads made of low-density polyethylene (Novatec LL, manufactured by Nippon Polyethylene Co., Ltd.) are melted at 140 ° C. and formed into a long film having a thickness of 100 μm using an extruder, and the base film 12a is formed. Created.

(Preparation of adhesive layer composition)
<Adhesive layer composition 1A>
To an acrylic copolymer obtained by copolymerizing 50 mol% of n-butyl acrylate, 40 mol% of 2-ethylhexyl acrylate, 4 mol% of methyl methacrylate, 1 mol% of methacrylic acid, and 5 mol% of 2-hydroxyethyl acrylate, 2-isocyanate ethyl methacrylate was added. By addition reaction, an ultraviolet curable acrylic copolymer was obtained. At this time, the polymerization amount of the 2-hydroxyethyl acrylate was adjusted such that the obtained ultraviolet curable acrylic copolymer had a hydroxyl value of 5 mgKOH / g. Further, methyl ethyl ketone (MEK: SP value = 9.3) was used as a solvent (solvent 1) in the polymerization.

  100 parts by weight of the obtained ultraviolet curable acrylic copolymer, 3 parts by weight of Coronate L manufactured by Nippon Polyurethane Industry Co., Ltd. as a curing agent, 2 parts by weight of Irgacure 184 manufactured by Ciba Geigy Japan, Ltd. as a photopolymerization initiator, and MEK After adding a solution obtained by dissolving and mixing (solvent at the time of mixing: solvent 2) using 50 parts by mass, the mixture was stirred and mixed for 30 minutes using a stirrer to obtain adhesive composition 1A.

<Adhesive layer composition 1B>
The pressure-sensitive adhesive layer composition was the same as the pressure-sensitive adhesive composition 1A, except that the solvent for the polymerization (solvent 1) and the solvent for the mixing (solvent 2) were changed to toluene (SP value = 8.8) instead of MEK. 1B was obtained.

<Adhesive layer composition 1C>
The pressure-sensitive adhesive layer was the same as the pressure-sensitive adhesive layer composition 1A, except that the solvent for the polymerization (solvent 1) and the solvent for the mixing (solvent 2) were changed to ethyl acetate (SP value = 9.1) instead of MEK. Composition 1C was obtained.

<Adhesive layer composition 1D>
Adhesive as in the adhesive layer composition 1A, except that the solvent (solvent 1) for polymerization was ethyl acetate and the solvent (solvent 2) for mixing was isopropyl alcohol (IPA: SP value = 11.5). A layer composition 1D was obtained. In this pressure-sensitive adhesive layer composition 1D, two types of solvents, ethyl acetate (solvent 1) and isopropyl alcohol (solvent 2), are used as solvents.

<Adhesive layer composition 1E>
Adhesive as in the adhesive layer composition 1A, except that the solvent (solvent 1) during polymerization was toluene and the solvent (solvent 2) during mixing was butyl acetate (butyl acetate: SP value = 8.5). Layer composition 1E was obtained. In this pressure-sensitive adhesive layer composition 1E, two types of solvents, toluene (solvent 1) and butyl acetate (solvent 2), are used as solvents.

  The said adhesive layer composition 1A-1E was apply | coated to the base film 12a so that the dry film thickness might be 10 micrometers, respectively, and the adhesive film 12 was produced.

(Preparation of adhesive layer composition)
<Adhesive layer composition 2A>
55 parts by mass of a cresol novolac type epoxy resin (epoxy equivalent 197, molecular weight 1200, softening point 70 ° C.) as an epoxy resin, 45 parts by mass of a phenol resin (hydroxyl equivalent 175) as a curing agent, and γ-mercaptopropyltrimethoxy as a silane coupling agent A composition consisting of 1.7 parts by mass of silane, 3.2 parts by mass of γ-ureidopropyltriethoxysilane, and 32 parts by mass of silica filler (average particle size 0.016 μm) was added as a solvent (solvent 1) methyl ethyl ketone (MEK). 120 parts by mass was added and mixed with stirring, and kneaded for 90 minutes using a bead mill. To this was added 280 parts by mass of acrylic resin (weight average molecular weight: 800,000, glass transition temperature -8 ° C, MEK 80% contained) and 0.5 part by mass of 1-cyanoethyl-2-phenylimidazole as a curing accelerator, and a stirrer was used. The mixture was stirred and mixed for 30 minutes and vacuum degassed to obtain an adhesive layer composition 2A.

<Adhesive layer composition 2B>
Adhesive layer composition 2B was obtained in the same manner as adhesive layer composition 2A, except that two types of solvents, MEK (solvent 1) and xylene (SP value = 8.8, solvent 2), were used as the solvent.

<Adhesive layer composition 2C>
An adhesive layer composition 2C was obtained in the same manner as the adhesive layer composition 2A, except that two types of solvents, MEK (solvent 1) and cyclohexanone (SP value = 9.9, solvent 2) were used as the solvent.
<Adhesive layer composition 2D>
An adhesive layer composition 2D was obtained in the same manner as the adhesive layer composition 2A, except that two solvents, MEK (solvent 1) and dimethylformamide (DMF: SP value = 11.9, solvent 2) were used as the solvent. .

About each wafer processing tape of Examples 1-4 and Comparative Examples 1-3, the residual solvent amount and the pick-up defect rate were measured. The results are shown in Table 1.
(Residual solvent amount measurement method)
Each of the pressure-sensitive adhesive layer and the adhesive layer was quantified, immersed in acetone, allowed to stand at room temperature, the supernatant was collected, and quantitative analysis was performed by GC / MS (gas chromatograph mass meter).
(Measurement method of pickup defect rate)
The wafer processing tapes of Examples 1 to 4 and Comparative Examples 1 to 3 were heated and bonded to a silicon wafer (semiconductor wafer) having a thickness of 100 μm and a diameter of 200 mm at 70 ° C., and the semiconductor wafer was diced (DFD 6340 made by Disco). ). Next, the semiconductor wafer is fixed on a dicing apparatus and diced to 5 × 5 mm at a speed of 100 mm / sec. Then, the adhesive layer is irradiated with ultraviolet rays at 500 mJ / cm ² with an air-cooled high-pressure mercury lamp. Pick-up was performed using an apparatus (manufactured by NEC Machinery). The pickup error rate% (/ 100) due to the double die in which the adjacent chips are lifted together during this pickup was evaluated.

In this evaluation, only one semiconductor chip 2 was picked up at the time of picking up, and the picking up was successful when the adhesive layer 13 peeled off from the adhesive layer 12b was held on this semiconductor chip. In addition, when two or more adjacent semiconductor chips 2 are lifted together at the time of pick-up, a pick-up error occurs due to a double die. Then, the pickup error occurrence rate for 100 picked up semiconductor chips was obtained.

  In Examples 1 to 4, the difference between the SP value of the solvent of the pressure-sensitive adhesive layer 12b having a residual solvent amount exceeding 15 μg / g and the SP value of the solvent of the adhesive layer 13 having a residual solvent amount exceeding 15 μg / g is “1”. Therefore, since the melting of the solvent of the pressure-sensitive adhesive layer 12b and the solvent of the adhesive layer 13 is reduced and the adhesion between the pressure-sensitive adhesive layer and the adhesive layer is lowered, the pickup defect rate is low. On the other hand, in Comparative Examples 1 to 3, the difference between the SP value of the solvent in the adhesive layer having a residual solvent amount exceeding 15 μg / g and the SP value of the solvent in the adhesive layer having a residual solvent amount exceeding 15 μg / g is Since it is smaller than “1”, the solvent of the pressure-sensitive adhesive layer and the solvent of the adhesive layer increase in melting, and the adhesiveness between the pressure-sensitive adhesive layer and the adhesive layer increases, so that the pickup defect rate is high.

  As the difference between the SP value of the solvent exceeding the predetermined residual amount of the pressure-sensitive adhesive layer 12b and the SP value of the solvent exceeding the predetermined residual amount of the adhesive layer 13 becomes smaller, both solvents are more easily melted. Will increase. Conversely, as the difference in SP value increases, both solvents are less likely to melt, and the melting of both solvents decreases. As a result of the experiment, as shown in Table 1, when the difference in SP value of the solvent with the residual solvent amount exceeding 15 μg / g is set to “1” or more, the residual solvent of the adhesive layer 12b and the residual solvent of the adhesive layer 13 It became difficult to melt, and the semiconductor chip with the adhesive layer separated in the pickup process can be easily peeled off from the pressure-sensitive adhesive layer 12b.

According to the wafer processing tape 10 according to this embodiment, the pressure-sensitive adhesive layer 12b and the adhesive layer 13 are residual solvents in which the residual solvent amount exceeds 15 μg / g, and the difference in solubility parameter (SP value) is 1. Since the different residual solvents are contained, in the step of picking up the semiconductor chip 2 with the adhesive layer 13 separated as shown in FIG. Less melting of layer 13 with residual solvent. Therefore, the separated semiconductor chip 2 with the adhesive layer 13 can be easily peeled from the pressure-sensitive adhesive layer 12b in the pickup process, and stable pickup can be performed. Thereby, the pickup defect rate can be reduced.
Therefore, in the step of picking up the separated semiconductor chip 2 with an adhesive layer, the peeling between the adhesive layer 12b and the adhesive layer 13 is not performed without increasing the push-up force of the pin 31 as shown in FIG. It is possible to realize a wafer processing tape that facilitates the process.

In addition, this invention can also be changed and embodied as follows.
Although the said embodiment demonstrated the case where an adhesive layer composition contained 1 type or 2 types of solvents, this invention is applicable also when an adhesive layer composition contains 2 or more types of solvents. It is.
In the above embodiment, the case where the adhesive layer composition contains one or two kinds of solvents has been described. However, the present invention is also applicable when the adhesive layer composition contains two or more kinds of solvents. It is.
Therefore, the present invention is for processing a wafer in which the pressure-sensitive adhesive layer and the adhesive layer contain a residual solvent having a residual solvent amount exceeding 15 μg / g and having a difference in solubility parameter of 1 or more. Widely applied to tape.

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 pressure-sensitive adhesive layer and the adhesive layer are residual solvents having a residual solvent amount exceeding 15 μg / g, and contain different residual solvents having a solubility parameter difference of 1 or more. tape.   The wafer processing tape according to claim 1, wherein the adhesive layer contains two or more kinds of solvents.   The tape for wafer processing according to claim 1, wherein the pressure-sensitive adhesive layer contains two or more kinds of solvents.

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