JP2018195616A - Adhesive tape for semiconductor processing - Google Patents

Abstract

To provide an adhesive tape for semiconductor processing capable of quickly peeling a package from the adhesive tape for semiconductor processing with any pickup of pushing up with a pin, scraping off and scrapping, after dicing while reducing occurrence of package frying generated at a time of dicing.SOLUTION: The adhesive tape for semiconductor processing having an adhesive layer on a substrate film is so configured that 5% modulus of the adhesive tape for semiconductor processing is 3.0 to 15.0 MPa, shearing adhesion to Si before UV irradiation is 30 to 400 N/cm, and shearing adhesion to Si after UV irradiation is 150 to 700 N/cm.SELECTED DRAWING: Figure 1

Description

The present invention relates to an adhesive tape for semiconductor processing.
More particularly, the present invention relates to a dicing adhesive tape suitable for fixing and holding a semiconductor wafer when dicing the semiconductor wafer into chips, and a dicing adhesive tape used for semiconductor package processing. In particular, the present invention relates to a dicing adhesive tape suitable for high-density mounting semiconductor package processing.

  The dicing adhesive tape protects and fixes a wafer during a dicing process in which a semiconductor wafer on which a circuit pattern is formed is separated into chips. Specifically, after a semiconductor wafer is fixed to an adhesive tape, it is divided (diced) by a rotary blade called a dicing blade to form semiconductor chips separated into chips. The semiconductor chip is held by the adhesive tape until the pickup process.

Thereafter, when a plurality of semiconductor chips are collectively molded with a package resin and individually separated to form individual semiconductor packages, they are affixed to a dicing tape and fixed, and dicing is performed with a dicing blade. Thus, in the dicing process of the package collectively sealed with the resin, the load at the time of cutting is large, and the package resin contains a release agent and the resin surface has a structure with minute irregularities. For this reason, the adhesive used in the dicing tape (hereinafter also referred to as “semiconductor processing tape”) can hold the package firmly, and the package is not held during dicing and is scattered (hereinafter referred to as “package”). A flexible adhesive is used to prevent problems such as “fly”.
On the other hand, the use of a flexible pressure-sensitive adhesive causes problems such as adhesion of the pressure-sensitive adhesive to the side surface of the package due to dicing and peeling of the laser mark stamped on the package.

Conventionally, studies have been made to reduce the occurrence of package fly.
For example, an adhesive tape using a (meth) acrylic acid alkyl ester for the adhesive layer has been proposed (see Patent Document 1).
As semiconductor chips become smaller and thinner, packages that are encapsulated with resin have become smaller and more precise.
In order to reduce the size, a conventional pick-up method using pin push-up also pushes up with a high pin height in order to prevent chipping due to rubbing between adjacent packages during pick-up.
However, by pushing up at a high pin height, there arises a problem that a package adjacent to the target package can be removed together, or that the pickup takes a very long time.
Therefore, the tape is bent by rubbing the back of the tape with tweezers, etc., and the package is dropped at a stroke (hereinafter referred to as “scraping off”) to pick up or between the package / glue surfaces, called scraping. Pick-up has come to be carried out in such a way that it is peeled off (slashed) with a trigger bar (knife) and peeled off from the tape.

JP 2007-100064 A

  Also, in recent years, there has been a problem that conventional semiconductor processing tapes cannot cope with a wide variety of pickup methods due to the change of the pickup method due to the downsizing of the package and the unification of tapes of semiconductor processing manufacturers due to cost reduction.

  For example, the performance of a tape required for high pin-up (Picking-up) includes a flexibility that can withstand a push-up at a high pin height using thin pins without breaking. The tape performance required for rubbing off includes an appropriate tape rigidity that can be easily scraped off from the back surface. Furthermore, the tape performance required for scraping includes easy peelability that allows the package to be peeled by a force in the shear direction.

  The present invention is intended to solve the problems associated with the prior art as described above, while reducing the occurrence of package fly that occurs during dicing, and after dicing, push-up with a pin, scraping off, It is an object of the present invention to provide an adhesive tape for semiconductor processing, which can peel the package from the adhesive tape for semiconductor processing by any scraping pickup.

As a result of intensive studies, the present inventors have found that it is important that the value of the 5% modulus of the adhesive tape and the value of the shear adhesive strength to Si before and after UV irradiation are set within appropriate ranges, respectively. The headline, the present invention has been reached.
That is, the said subject of this invention is solved by the following means.

[1] A semiconductor processing pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer on a substrate film,
The 5% modulus of the adhesive tape for semiconductor processing is 3.0 to 15.0 MPa, the shear adhesive strength to Si before UV irradiation is 30 to 400 N / cm ² , and the shear adhesive strength to Si after UV irradiation is A pressure-sensitive adhesive tape for semiconductor processing, which is 150 to 700 N / cm ² .
[2] The semiconductor processing pressure-sensitive adhesive tape according to item [1], wherein the pressure-sensitive adhesive used in the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive.
[3] The adhesive tape for semiconductor processing according to [1] or [2], which is used for dicing and picking up a semiconductor package.

In the present invention, the term “acrylic” includes methacrylic.
In order to make the acrylic system clearer, the parenthesis part of “(meth)” means that it may or may not be present as in the case of (meth) acrylic system. For example, (meth) acrylic system Can be either acrylic or methacrylic or both. This also has the same meaning for (meth) acrylic acid and (meth) acrylate.

The adhesive tape for semiconductor processing of the present invention reduces the occurrence of package fly that occurs during dicing, and after dicing, the package can be quickly and reliably picked up by pins, scraped off, or scraped. It can be peeled from the adhesive tape.
Here, by controlling the modulus value of the adhesive tape for semiconductor processing, it is possible to obtain appropriate flexibility that does not break when the pin is pushed up at a high pin height and is easy to be scraped off. In addition, by controlling the value of the shear adhesive force of the adhesive tape for semiconductor processing, it is possible to achieve both the reduction of package fly generation and the ease of picking up by scraping.

It is a cross-sectional schematic diagram which shows one Embodiment of the adhesive tape for semiconductor processing of this invention. It is a schematic sectional drawing which shows the state which bonded the semiconductor processing adhesive tape to the semiconductor wafer, and was fixed to the holder in the dicing and pick-up process of the semiconductor wafer which uses the adhesive tape for semiconductor processing of this invention. It is a schematic sectional drawing which shows the state which separated the semiconductor wafer into the semiconductor chip in the dicing and pick-up process of the semiconductor wafer which uses the adhesive tape for semiconductor processing of this invention. It is a schematic sectional drawing which shows the process of expanding the adhesive tape for semiconductor processing by an expander in the direction of a dotted line arrow in the dicing and pick-up processes of the semiconductor wafer using the adhesive tape for semiconductor processing of the present invention. It is a schematic sectional drawing which shows the process of picking up a semiconductor chip in the dicing and pick-up process of the semiconductor wafer which uses the adhesive tape for semiconductor processing of this invention.

  Below, the adhesive tape for semiconductor processing of this invention is demonstrated in detail.

<< Semiconductor processing adhesive tape >>
The adhesive tape 12 for semiconductor processing of this invention has the adhesive layer 2 on the at least one surface on the base film 1 like the schematic sectional drawing typically shown in FIG.
Hereinafter, the base film 1 will be described in order.

<Base film 1>
In the present invention, it is preferable that the base film 1 has a uniform and isotropic expandability in that an interval between packages spreads in all directions in an expanding process at the time of picking up with pins. Moreover, it is preferable that the rigidity of the base film 1 does not become too large in that the force required to expand the base film does not become too large and the load on the apparatus does not increase. Furthermore, it does not specifically limit about the material of the base film 1, For example, any of crosslinked resin and non-crosslinked resin may be sufficient.

In general, the cross-linked resin has a greater restoring force against tension compared to the non-cross-linked resin, and is excellent in the recoverability from the stretched state after the expanding step. On the other hand, the non-crosslinked resin has a low restoring force against tension compared to the crosslinked resin. Therefore, since the tape is difficult to shrink after deformation when picked up by scraping, it is excellent in that picking up by scraping is easy. Of the non-crosslinked resins, olefinic non-crosslinked resins are more preferably used.
The base film 1 may have a single layer structure or a multilayer structure.

(Crosslinked resin)
As the cross-linked resin, an ethylene- (meth) acrylic acid binary copolymer or a terpolymer having ethylene- (meth) acrylic acid- (meth) acrylic acid alkyl ester as a main polymer component is a metal ion. It is preferably made of an ionomer resin crosslinked with.
These cross-linked resins are particularly suitable in that they are suitable for the expanding process in terms of uniform expansibility and have a strong restoring force when heated by cross-linking.
The metal ion contained in the ionomer resin is not particularly limited, and examples include ions such as zinc and sodium. Zinc ions are preferred from the viewpoint of low elution and low contamination.
Examples of the alkyl (meth) acrylate include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate. Can be mentioned.

In addition to the above ionomer resin, the cross-linked resin may be polyethylene such as low density polyethylene having a specific gravity of 0.910 or more and less than 0.930, ultra-low density polyethylene having a specific gravity of less than 0.910, or ethylene-vinyl acetate copolymer. A resin cross-linked by irradiating an energy beam such as an electron beam to a resin selected from the coalesced is also preferably used.
These cross-linked resins have a certain uniform extensibility because a cross-linked site and a non-cross-linked site coexist in the resin. In addition, since the restoring force works, it is also suitable for removing tape slack generated in the expanding process. Since the molecular chain structure contains almost no chlorine, the tape that is no longer needed after use is incinerated. However, since chlorinated aromatic hydrocarbons such as dioxin and its analogs are not generated, the environmental load is small. By appropriately adjusting the amount of energy rays applied to the polyethylene or ethylene-vinyl acetate copolymer, a resin having sufficient uniform expandability can be obtained.

(Non-crosslinked resin)
Moreover, as said non-crosslinked resin, the mixed resin composition of a polypropylene and a styrene-olefin copolymer is mentioned, for example.
As polypropylene, for example, a homopolymer of propylene or a block-type or random-type propylene-ethylene copolymer can be used. A random type propylene-ethylene copolymer is preferred because of its low rigidity.
From the point that the content of the ethylene structural unit in the propylene-ethylene copolymer is 0.1% by mass or more, the tape has an appropriate rigidity, and the compatibility of the resins in the mixed resin composition is high. preferable. When the tape has an appropriate rigidity, pick-up property by rubbing is improved, and when the compatibility between the resins is high, the extrusion discharge amount is easily stabilized. The content of the ethylene structural unit is more preferably 1% by mass or more. Moreover, it is preferable that the content rate of the ethylene structural unit in a propylene-ethylene copolymer is 7 mass% or less from the point which a polypropylene becomes easy to superpose | polymerize stably, More preferably, it is 5 mass% or less.

Examples of the olefin structural unit in the styrene-olefin copolymer include ethylene, propylene, butadiene, and isoprene, and butadiene and isoprene are preferable.
As the styrene-olefin copolymer, a hydrogenated one may be used. When the styrene-olefin copolymer is hydrogenated, it has good compatibility with propylene and can prevent embrittlement and discoloration due to oxidative degradation caused by double bonds in the olefin.
Moreover, it is preferable that the content rate of the styrene structural unit in a styrene-olefin copolymer is 5 mass% or more at the point which is easy to polymerize a styrene-olefin copolymer stably. Further, the content of the styrene structural unit is preferably 40% by mass or less from the viewpoint of flexibility and extensibility, more preferably 25% by mass or less, and further preferably 15% by mass or less.
As the styrene-olefin copolymer, either a block copolymer or a random copolymer may be used. Random type copolymers are preferred because the styrene phase is uniformly dispersed and expandability and flexibility with less uneven distribution can be obtained. A block copolymer is preferable, a styrene-olefin-styrene block copolymer is more preferable, and a styrene-hydrogenated olefin-styrene block copolymer is more preferable from the viewpoint of easily revealing the characteristics of each constituent component.

It is preferable that the content ratio of polypropylene in the mixed resin composition is 30% by mass or more in that the thickness unevenness of the base film 1 can be suppressed. If the thickness is uniform, the expandability tends to be isotropic. The content of the polypropylene is more preferably 50% by mass or more. Moreover, it is easy to adjust the rigidity of the base film 1 as the content rate of the said polypropylene is 90 mass% or less. If the rigidity of the base film 1 becomes too large, the force required to expand the base film 1 becomes large, which increases the load on the device and makes it difficult to expand or tears when picking up with a pin Therefore, it is important to adjust to an appropriate rigidity.
The lower limit of the content of the styrene-olefin copolymer in the mixed resin composition is preferably 10% by mass or more from the viewpoint of easy adjustment to the rigidity of the base film 1 suitable for the apparatus. Further, the upper limit is preferably 70% by mass or less, and more preferably 50% by mass or less, from the viewpoint that thickness unevenness can be suppressed.

The material of the base film 1 is not limited to the above resin as long as it satisfies the performance as the adhesive tape for semiconductor processing of the present invention. The base film 1 may be composed of one kind of resin or may be composed of two or more kinds of resins. However, when composed of two or more resins, when the two or more resins are unified as crosslinkable or non-crosslinkable, it is preferable from the viewpoint of expressing each characteristic more enhanced, When a crosslinkable resin and a non-crosslinkable resin are combined and laminated, it is preferable in that each defect is compensated.
The thickness of the base film 1 is not particularly limited, but it is sufficient that the base film 1 has sufficient strength that it can be easily stretched in the expanding process of the semiconductor processing pressure-sensitive adhesive tape 12 and does not break during pickup. Specifically, for example, 50 to 200 μm is preferable, and 100 to 150 μm is more preferable.

  As a manufacturing method of the base film 1 having a multilayer structure, a conventionally known extrusion method, laminating method, or the like can be used. When the laminating method is used, an adhesive may be interposed between the layers. Any conventional adhesive can be used as the adhesive.

<Adhesive layer 2>
The pressure-sensitive adhesive layer 2 can be formed of any conventional various pressure-sensitive adhesives. Such a pressure-sensitive adhesive is not limited at all, but for example, a pressure-sensitive adhesive based on rubber, acrylic, silicone, polyvinyl ether or the like is used.
In the adhesive, the content of the base polymer is preferably 20 to 100% by mass, and more preferably 30 to 90% by mass.
In the present invention, an acrylic pressure-sensitive adhesive is preferable because of a small amount of adhesive residue on the semiconductor package as an adherend.

In the pressure-sensitive adhesive, a crosslinking agent can be blended from the viewpoint of adding cohesive force to the base polymer and setting the initial adhesive force to an arbitrary value.
The crosslinking agent is appropriately selected depending on various base polymers, and examples thereof include isocyanate crosslinking agents, epoxy crosslinking agents, metal chelate crosslinking agents, aziridine crosslinking agents, and amine resins.

The isocyanate-based crosslinking agent can be used for a base polymer having a hydroxy group, an amino group or the like (for example, a polymer having a hydroxyalkyl (meth) acrylate described later as a structural unit).
As the isocyanate-based crosslinking agent, a polyvalent isocyanate compound is used. For example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane -4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, Examples include lysine diisocyanate and lysine triisocyanate, and commercially available products include Coronate L (trade name) manufactured by Nippon Polyurethane.
In an adhesive, 0.1-10 mass parts is preferable with respect to 100 mass parts of base polymers, and, as for an isocyanate type crosslinking agent, 0.1-5 mass parts is more preferable.

  In addition to the above-mentioned base polymer and crosslinking agent, the pressure-sensitive adhesive can contain various additive components as long as the effects of the present invention are not impaired.

A radiation-curing type or heat-foaming type pressure-sensitive adhesive can also be used.
As the radiation-curable pressure-sensitive adhesive, a pressure-sensitive adhesive that can be easily peeled at the time of peeling by being cured with ultraviolet rays, electron beams, or the like can be used. On the other hand, as the heat-foaming pressure-sensitive adhesive, a pressure-sensitive adhesive that is easily peeled off by foaming or expansion by heating can be used. Furthermore, an adhesive that can be used for dicing and die bonding can also be used as the adhesive. As the radiation curable pressure-sensitive adhesive, for example, those described in JP-B-1-56112, JP-A-7-135189 and the like are preferably used, but are not limited thereto.
In the present invention, it is preferable to use an ultraviolet curable adhesive. The ultraviolet curable pressure-sensitive adhesive only needs to have a property of being cured by radiation (ultraviolet rays) to form a three-dimensional network. For example, a low molecular weight compound (hereinafter referred to as a photopolymerizable compound) having at least two photopolymerizable carbon-carbon double bonds in the molecule with respect to a normal rubber-based or acrylic pressure-sensitive base resin (base polymer). ) And a photopolymerization initiator are included.

The above rubber-based or acrylic base resins are natural rubber, rubber polymers such as various synthetic rubbers, or poly (meth) acrylic acid alkyl esters, (meth) acrylic acid alkyl esters, (meth) acrylic acid alkyl esters. And an acrylic polymer such as a copolymer of the other unsaturated monomer copolymerizable therewith (hereinafter referred to as “other unsaturated monomer”).
As said (meth) acrylic-acid alkylester structural unit, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, etc. are mentioned.
Examples of the structural unit composed of the other unsaturated monomer include hydroxyalkyl (meth) acrylate (for example, 2-hydroxyethyl acrylate).

As said photopolymerizable compound, it can use without a restriction | limiting as long as hardening reaction occurs by irradiating an ultraviolet-ray or an electron beam. Examples of such a photopolymerizable compound include tetramethylol methane tetraacrylate.
From the point which controls adhesive performance and a flexibility in an adhesive, 10-180 mass parts is preferable with respect to 100 mass parts of base polymers, and 20-170 mass parts is more preferable.

In the case of an ultraviolet curable pressure-sensitive adhesive, a polymerization curing time and an ultraviolet irradiation amount due to ultraviolet irradiation can be reduced by blending a photopolymerization initiator in the pressure-sensitive adhesive.
Specific examples of such a photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, Examples include β-chloranthraquinone and α-hydroxycyclohexyl phenyl ketone.
In the ultraviolet curable adhesive, the photopolymerization initiator is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the base polymer.

The mass average molecular weight of the base polymer of the acrylic pressure-sensitive adhesive is preferably 100,000 to 2,000,000, more preferably 300,000 to 1,500,000.
The glass transition temperature of the base polymer of the acrylic pressure-sensitive adhesive is preferably -70 ° C to 15 ° C, more preferably -66 ° C to 0 ° C.
The weight average molecular weight is obtained by standard polystyrene conversion by gel permeation chromatography (GPC).
The glass transition temperature is a value obtained by, for example, measuring by a differential scanning calorimetry (DSC) at a temperature rising rate of 5 ° C./min.

  Although the thickness in particular of the adhesive layer 2 is not restrict | limited, Preferably it is 4-40 micrometers, Most preferably, it is 5-30 micrometers.

<5% modulus of adhesive tape for semiconductor processing>
In the present invention, the 5% modulus of the adhesive tape for semiconductor processing is 3.0 to 15.0 MPa.
The 5% modulus of the adhesive tape for semiconductor processing is preferably 6.0 to 13.0 MPa, and more preferably 7.0 to 12.0 MPa.

  If the 5% modulus of the adhesive tape for semiconductor processing is less than 3.0 MPa, the adhesive tape for semiconductor processing is flexible, so that no force is transmitted when the package is scraped off, and the package remains on the adhesive tape for semiconductor processing. May end up. On the other hand, if the 5% modulus of the adhesive tape for semiconductor processing exceeds 15.0 MPa, the adhesive tape 12 for semiconductor processing is too rigid, so that the sticking property to the semiconductor package is deteriorated and package fly may occur during dicing. is there.

The 5% modulus is obtained by measuring the stress at 5% strain according to JIS K 7127/2/300.
In the present invention, the MD direction and the TD direction are each measured five times, and a value obtained by averaging all these measured values is taken as a value of 5% modulus.

  5% modulus can be adjusted to the said range by adjusting suitably the kind and compounding quantity of resin which comprise the base film 1, and the kind and compounding quantity of the adhesive which comprise the adhesive layer 2, respectively.

<Shear adhesive strength of adhesive tape for semiconductor processing>
In the present invention, the shear adhesive strength of the adhesive tape for semiconductor processing is 30 to 400 N / cm ² before UV irradiation with respect to Si, and 150 to 700 N / cm ² after UV irradiation with respect to Si.
The shear adhesive strength of the pressure-sensitive adhesive tape for semiconductor processing is preferably 50 to 350 N / cm ^{2 and} more preferably 70 to 300 N / cm ² before UV irradiation with respect to Si. Moreover, 180-650 N / cm < ² > is preferable after UV irradiation with respect to Si, and 200-600 N / cm < ² > is further more preferable.

If the adhesive strength of the adhesive tape for semiconductor processing is less than 30 N / cm ² before UV irradiation with respect to Si, the chip (package) holding force of the adhesive tape for semiconductor processing will be weak, so package fly will occur during dicing. May end up. On the other hand, when the shear adhesive strength of the adhesive tape for semiconductor processing exceeds 400 N / cm ² before UV irradiation with respect to Si, the holding power is too strong, which may lead to deterioration of pick-up property and generation of adhesive residue. . Also, if the adhesive strength of the adhesive tape for semiconductor processing is less than 150 N / cm ² after UV irradiation with respect to Si, the chip (package) holding force of the adhesive tape for semiconductor processing will be weak, so pick-up with pins Occasionally, the picked up adjacent package may fly away. On the other hand, if the shear adhesive strength of the adhesive tape for semiconductor processing exceeds 700 N / cm ² after UV irradiation with respect to Si, the holding power is too strong, which may lead to deterioration of pick-up property in scrapping.

  The shear adhesive strength of the semiconductor processing pressure-sensitive adhesive tape is obtained by die shear strength. The average die shear strength measured for 10 samples is taken as the shear adhesive strength. Details are described in the Examples section.

  The adhesive tape 12 for semiconductor processing of the present invention is bonded to a semiconductor wafer (package) 13 and can be used for dicing and picking up a semiconductor wafer as shown in FIGS. In the processing method of the semiconductor wafer 13 using the adhesive tape 12 for semiconductor processing of the present invention, not cutting up to the base film 1 reduces the cutting resistance of the dicing blade and makes the cutting of the semiconductor wafer 13 smooth. From the viewpoint of reducing chipping. In order to prevent the cutting from reaching the base film 1, for example, the setting of the cutting depth of the dicing apparatus to be used may be appropriately changed according to the manual.

The adhesive tape 12 for semiconductor processing of the present invention is particularly preferably used when picking up semiconductor chips collectively molded with a package resin by dicing with a dicing blade to form individual semiconductor packages and picking them up. be able to. In this case, the pick-up process is not limited to the usual method of expanding the adhesive tape for semiconductor processing shown in FIGS. 4 and 5, and individual semiconductors can be picked up by any of the pick-up method using pins, scraping off, and scraping. The package can be carried out while suppressing the occurrence of package fly. For this reason, individual semiconductor packages can be manufactured with high manufacturing efficiency (high production speed, high pickup efficiency).
The batch molding of the semiconductor chip (package) 14 with the package resin can be performed by a conventional method, and the package resin can also be a package resin that is usually used.
The adhesive tape 12 for semiconductor processing of the present invention can be used for dicing and picking up of semiconductor chips that are collectively molded with a package resin, but from dicing the semiconductor wafer 13 to dicing of semiconductor chips that are collectively molded with a package resin, It can also be used in a series of steps up to pickup.

  The bare wafer used in the present invention is not particularly limited, and can be appropriately selected from any conventionally used bare wafers.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to this.

<Manufacture of base film 1>
1) Base film A
Styrene-hydrogenated isoprene-styrene block copolymer (SEPS) [trade name: Septon KF-2104, manufactured by Kuraray Co., Ltd.] and homopropylene (PP) [trade name: J-105G, Ube Industries, Ltd. Made at a mixing ratio shown in Table 1 below using a twin-screw kneader at about 200 ° C., and then processed by film extrusion at about 200 ° C. to form a substrate film A having a thickness of 150 μm. Manufactured.

2) Base film B to E
Base films B to E having a thickness of 150 μm were manufactured in the same manner as in the manufacture of the base film A, except that a resin having a blending ratio shown in Table 1 below was used.

3) Base film F
Styrene-hydrogenated butadiene-styrene copolymer (SEBS) [trade name: Dynalon 8600P, manufactured by JSR Corporation] and homopropylene (PP) [trade name: J-105G, manufactured by Ube Industries, Ltd.] Were mixed at about 200 ° C. using a biaxial kneader at the blending ratio shown in Table 1 below, and then processed by film extrusion at about 230 ° C. to produce a substrate film F having a thickness of 150 μm. .

The composition of each base film is summarized in Table 1 below.
In the table, a blank means not used.

<Preparation of adhesive>
1) Adhesive a
A polyisocyanate compound [trade name: Coronate L] is added to 100 parts by mass of an acrylic base polymer a (a copolymer composed of ethyl acrylate, butyl acrylate, 2-hydroxyethyl acrylate, mass average molecular weight 700,000, glass transition temperature: −30 ° C.). Manufactured by Nippon Polyurethane Industry Co., Ltd.] 1 part by mass, 50 parts by mass of tetramethylolmethane tetraacrylate as a compound having a photopolymerizable carbon-carbon double bond, and 1 part by mass of α-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator Were added and mixed to obtain an adhesive a.

2) Adhesives b to e
In the same manner as the pressure-sensitive adhesive a, the pressure-sensitive adhesives b to e were obtained by mixing at the blending ratio shown in Table 2 below.

3) Adhesive f
A polyisocyanate compound [trade name: trade name: 100 parts by mass of acrylic base polymer b (copolymer comprising 2-ethylhexyl acrylate, methyl acrylate, 2-hydroxyethyl acrylate, mass average molecular weight 800,000, glass transition temperature: −60 ° C.) Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.] 1 part by mass, 50 parts by mass of tetramethylolmethane tetraacrylate as a compound having a photopolymerizable carbon-carbon double bond, and α-hydroxycyclohexyl phenyl ketone 1 as a photopolymerization initiator Mass part was added and mixed to obtain an adhesive f.

4) Adhesive g
In the same manner as the pressure-sensitive adhesive f, the pressure-sensitive adhesive g was obtained by mixing at the blending ratio shown in Table 2 below.

The composition of each pressure-sensitive adhesive is summarized in Table 2 below.
In the table, a blank means not used.

Example 1
On one surface of the base film A, the pressure-sensitive adhesive a was applied to a thickness of 20 μm to form a pressure-sensitive adhesive layer 2, and the semiconductor processing pressure-sensitive adhesive tape 12 of Example 1 was manufactured.

Examples 2-4
Each semiconductor processing pressure-sensitive adhesive tape 12 was produced in the same manner as in Example 1 except that the pressure-sensitive adhesives b, c and f were used.

Example 5
Except having used the said base film B, it carried out similarly to Example 1, and manufactured the adhesive tape 12 for semiconductor processing.

Example 6
Except having used the said base film C, it carried out similarly to Example 1, and manufactured the adhesive tape 12 for semiconductor processing.

Example 7
Except having used the said base film D, it carried out similarly to Example 3, and manufactured the adhesive tape 12 for semiconductor processing.

Example 8
Except having used the said base film F, it carried out similarly to Example 1, and manufactured the adhesive tape 12 for semiconductor processing.

Comparative Example 1
A semiconductor processing pressure-sensitive adhesive tape was produced in the same manner as in Example 6 except that the pressure-sensitive adhesive g was used.

Comparative Examples 2 and 3
Each adhesive tape for semiconductor processing was produced in the same manner as in Example 7 except that the adhesives d and e were used.

Comparative Example 4
A pressure-sensitive adhesive tape for semiconductor processing was produced in the same manner as in Example 1 except that the viscous substrate film E was used.

  Each of these adhesive tapes for semiconductor processing was evaluated for 5% modulus, shear adhesive strength, package fly and pickup success rate as follows.

(5% modulus)
Using each adhesive tape for semiconductor processing, a test piece was prepared in accordance with JIS K7127 / 2/300, and the 5% modulus was measured. For each test piece, the MD direction and the TD direction were measured five times each, and a value obtained by averaging all these measured values was taken as the test result.

(Shear adhesive strength)
The shear adhesive strength of the adhesive tape for semiconductor processing was evaluated by the following method.
For semiconductor processing by using a universal bond tester equipped with a 1000N load cell (trade name: 4000 series, manufactured by DAGE), pressing the bare wafer horizontally at a measurement speed of 50 μm / s, a measurement height of 350 μm, and a measurement temperature of 23 ° C. The die shear strength of the adhesive tape was measured. The average die shear strength measured for 10 samples was defined as shear adhesive strength.

(Package fly)
A QFN package (Quad Flat Non lead package, 60 mm × 150 mm, thickness 0.95 mm) was bonded to each semiconductor processing adhesive tape. Dicing was performed using a dicer (trade name, DFD6340, manufactured by DISCO Corporation) under the conditions of a blade rotation speed of 20000 rpm, a cutting speed of 30 mm / min, and a cutting depth of 70 μm into an adhesive tape to a size of 1 mm × 1 mm.
Individual packages after dicing were observed and evaluated according to the following evaluation criteria.

Evaluation criteria ○: All packages (chips) remain on the adhesive tape for semiconductor processing.
X: One or more packages are scattered.

(Pickup success rate)
Each semiconductor processing adhesive tape and QFN package (Quad Flat Non lead package, 60 mm x 150 mm, thickness 0.95 mm) are bonded together, and blade rotation speed is measured with a dicer (trade name, DFD6340, manufactured by DISCO Corporation) Dicing was performed under conditions of a size of 1 mm × 1 mm under the conditions of 20000 rpm, a cutting speed of 30 mm / min, and a cutting amount of 70 μm into the adhesive tape. After dicing, ultraviolet light was irradiated from the adhesive tape for semiconductor processing (metal halide lamp, UV intensity 30 mW / cm ² , integrated light amount 200 mJ / cm ² ) to reduce the adhesive strength of the adhesive tape.
Using the package with the adhesive tape for semiconductor processing after ultraviolet irradiation obtained above as a sample, the pickup was evaluated by the following three methods.
(1) Evaluation by pin pick-up Using the CAP-300II (trade name) manufactured by Canon Machinery Co., Ltd., pick-up success rate at a pin height of 300μm and pick-up at a pin height of 1000μm for the sample prepared above, and packaging of adjacent chips The presence or absence of the fly was confirmed.
In the table below, “With fly” means that the pick-up success rate was 100% at a pin height of 300 μm, but a package fly occurred at a pin height of 1000 μm, resulting in an inferior (NG) result. To do.
(2) Evaluation by rubbing off About the sample produced above, the back surface of the adhesive tape for semiconductor processing was rubbed with tweezers, and the package was dropped.
In the table below, all except “100%” are “NG”.
(3) Evaluation by scraping For the sample prepared above, the polycarbonate bar was applied to the boundary between the adhesive layer of the adhesive tape for semiconductor processing and the package surface as the adherend, and the package was scraped off.
In the table below, all except “100%” are “NG”.

The obtained results are summarized in Tables 3-1 and 3-2 below.
In the table, blank means not tested (ND).

From Table 3-1 above, the adhesive tapes for semiconductor processing of Examples 1 to 8 all have a 5% modulus value in the range of 3.0 to 15.0 MPa, and shear against Si before UV irradiation. Adhesive strength is 30 to 400 N / cm ² , shear adhesive strength to Si after UV irradiation is 150 to 700 N / cm ² , package fly does not occur at the time of dicing, and (i) pickup with pin ( The pickup by ii) scraping off and the pickup by (iii) scraping (scraping by bar) were both good.
On the other hand, the following can be understood from Table 3-2 above.
First, the pressure-sensitive adhesive tape for semiconductor processing of Comparative Example 1 has many oligomer components in the pressure-sensitive adhesive, and the value of 5% modulus is too small, and the shear adhesive strength of the pressure-sensitive adhesive tape for semiconductor processing to Si after UV irradiation is high. As a result of the value being too large, picking up by scrapping was difficult.
Next, the pressure-sensitive adhesive tape for semiconductor processing of Comparative Example 2 has a small amount of the elastomer component of the base material, a small amount of the oligomer component in the pressure-sensitive adhesive, and a value of 5% modulus is too large, and compared to Si before UV irradiation. As a result of the value of the shear adhesive force of the adhesive tape for semiconductor processing being too small, the sticking property to the semiconductor package was deteriorated and the package fly was generated. For this reason, subsequent tests and evaluations were suspended.
Moreover, the adhesive tape for semiconductor processing of Comparative Example 3 has a small amount of elastomer component in the base material, and a large amount of oligomer component in the adhesive, and the shear adhesive force of the adhesive tape for semiconductor processing to Si after UV irradiation is too small. As a result, the package fly of the adjacent package occurred at the time of picking up with the pin.
Furthermore, the adhesive tape for semiconductor processing of Comparative Example 4 has a large amount of the elastomer component of the base material, and as a result of the 5% modulus value being too small, the package remains on the adhesive tape for semiconductor processing by picking up by scraping. .

DESCRIPTION OF SYMBOLS 1 Base film 2 Adhesive layer 11 Holder 12 Adhesive tape for semiconductor processing 13 Semiconductor wafer 14 Semiconductor chip 15 Solid arrow direction 16 Expander 17 Dotted arrow direction

Claims (3)

A pressure-sensitive adhesive tape for semiconductor processing having a pressure-sensitive adhesive layer on a base film,
The adhesive tape for semiconductor processing has a 5% modulus of 3.0 to 15.0 MPa, a shear adhesive strength to Si before UV irradiation of 30 to 400 N / cm ² , and a shear adhesive strength to Si after UV irradiation. A pressure-sensitive adhesive tape for semiconductor processing, which is 150 to 700 N / cm ² .   The pressure-sensitive adhesive tape for semiconductor processing according to claim 1, wherein the pressure-sensitive adhesive used in the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive.   The pressure-sensitive adhesive tape for semiconductor processing according to claim 1, which is used for dicing and pickup of a semiconductor package.

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