JP2006202926A - Dicing tape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dicing tape which can be properly used for manufacturing an IC chip with a through electrode. <P>SOLUTION: The dicing tape is used for manufacturing the IC chip equipped with a through-electrode. The dicing tape is equipped with a base material and an adhesive layer which is laminated on the base material and 15 to 50 μm in thickness. The adhesive layer has a gel molar fraction of 30 to 80% and a storage elastic modulus of 5×10<SP>5</SP>Pa or above at a temperature of 10°C based on the dynamic viscoelasticity measured through a shearing method, under the conditions that the temperature rising rate is set at 3°C/min, the frequency is 10 Hz, and the strain is set at 0.5%. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a dicing tape that can be suitably used for manufacturing an IC chip with a through electrode.

In the conventional electronic circuit manufacturing method, an IC chip placed on a substrate is conductively connected by wire bonding. In recent years, development of a laminated circuit in which a plurality of IC chips are three-dimensionally laminated has been advanced in response to the increase in capacity and functionality of electronic circuits. Conventionally, in such a laminated circuit, the conductive connection of the IC chip is generally performed by wire bonding. However, due to the recent need for miniaturization and high functionality, the IC chip can be connected without wire bonding. A method of providing a through electrode on a chip and directly connecting the upper and lower conductive parts between IC chips has been developed as an effective technique.

As a method of manufacturing such an IC chip with a through electrode, for example, a through hole is formed in a predetermined position of a semiconductor wafer by plasma or the like, and a conductor such as copper is poured into the through hole, and then etching or the like is performed. Examples thereof include a method of providing a circuit and a through electrode on the surface of a semiconductor wafer. A semiconductor wafer provided with a circuit and a through electrode is diced by a conventional method to obtain individual IC chips with through electrodes.

In a normal dicing process, a semiconductor wafer is diced in a state of being stuck and fixed to an adhesive tape called a dicing tape, and formed into individual IC chips (for example, Patent Document 1). However, even if a semiconductor wafer provided with a circuit and a through electrode is attached to a conventional dicing tape for dicing, there is a problem that the dicing cannot be performed accurately or the IC chip is damaged.

JP 05-114647 A

An object of this invention is to provide the dicing tape which can be used suitably for manufacture of an IC chip with a penetration electrode in view of the said present condition.

The present invention is a dicing tape used for manufacturing an IC chip with a through electrode, and has a base material and an adhesive layer having a thickness of 15 to 50 μm laminated on the base material. A storage elastic modulus at 10 ° C. based on a dynamic viscoelasticity measured by a shearing method under conditions of a gel fraction of 30 to 80%, a frequency of 10 Hz, a set strain of 0.5%, and a heating rate of 3 ° C./min is 5 It is a dicing tape that is × 10 ⁵ Pa or more.
The present invention is described in detail below.

In a semiconductor wafer provided with a circuit and a through electrode, the through electrode usually protrudes to a height of about 10 to 30 μm on one or both surfaces. When the protrusion is an IC chip, it serves as a bump for conductive connection with the substrate or another IC chip. However, even if a conventional tying tape is affixed to a semiconductor wafer having such a protruding portion, the pressure-sensitive adhesive layer cannot sufficiently follow the protruding portion, and “float” occurs in that portion (FIG. 2A). . If there is such “floating”, the semiconductor wafer on the dicing tape is not sufficiently fixed, and the semiconductor wafer swings on the dicing tape due to the impact during dicing. It is considered that the IC chip is damaged. In order to suppress the occurrence of such “floating”, it is conceivable to increase the thickness of the pressure-sensitive adhesive layer or to adjust the gel fraction or the like to improve the unevenness followability. However, even if the occurrence of “floating” is suppressed by such a method, the problem that the dicing cannot be accurately performed or the IC chip is damaged cannot be solved.

As a result of intensive studies, the inventors have determined that the thickness of the pressure-sensitive adhesive layer is within a certain range, and that the gel fraction of the pressure-sensitive adhesive layer is within a certain range and at the same time a dicing tape having a storage elastic modulus of a certain level or more. For the first time when it was used, it was found that even a semiconductor wafer provided with a circuit and a through electrode could be diced accurately without being damaged.
This means that if the adhesive is too soft, even if it improves the unevenness followability of the adhesive layer and suppresses the occurrence of “floating”, the fixing of the semiconductor wafer on the dicing tape will still be insufficient and dicing When the semiconductor wafer swings on the dicing tape due to the impact of time (FIG. 2B), the semiconductor wafer is sufficiently fixed by setting the elastic modulus to a certain level or more. This is thought to be because it does not move up (FIG. 1). That is, in order to accurately dice a semiconductor wafer provided with a circuit and a through electrode without damaging it, a dicing tape having an adhesive layer that simultaneously satisfies high unevenness followability and high elastic modulus is required. .

In this way, even if the dicing tape has a UV curable pressure sensitive adhesive that reduces the peeling force due to UV irradiation, if the pressure sensitive adhesive layer of the dicing tape is sufficiently followed up to the protrusion, May be difficult to peel. This seems to be because, after following the protruding portion, even if the adhesive is cured by ultraviolet rays and the adhesive strength of the adhesive layer is lowered, it will be caught. In such a case, if it is attempted to forcibly remove the catch, the through electrode itself may be damaged or destroyed.
As a result of intensive studies, the present inventors have further shown that by including a gas generating agent that generates gas upon stimulation in the pressure-sensitive adhesive layer, if the stimulation is given at the time of peeling, it can be easily peeled without damaging the through electrode. I found it. This is presumably because gas is generated from the pressure-sensitive adhesive layer by stimulation, and the catching can be eliminated by the pressure of the generated gas.

The dicing tape of this invention has a base material and the adhesive layer laminated | stacked on the said base material.
Although it does not specifically limit as said base material, When the said adhesive layer contains the gas generating agent which generate | occur | produces gas by the irritation | stimulation mentioned later, it is preferable that it is what permeate | transmits or passes light, for example, acrylic, Examples thereof include a sheet made of a transparent resin such as olefin, polycarbonate, vinyl chloride, ABS, polyethylene terephthalate (PET), nylon, urethane, and polyimide, a sheet having a network structure, and a sheet having holes.

The pressure-sensitive adhesive layer has a gel fraction lower limit of 30% and an upper limit of 80%. If it is less than 30%, the cohesive force of the pressure-sensitive adhesive layer is low, and the dicing tape cannot be peeled off from the IC chip, or adhesive residue may be generated when peeled off. If it exceeds 80%, sufficient unevenness followability cannot be exhibited, and when it is attached to a semiconductor wafer provided with a circuit and a through electrode, “floating” occurs in the protruding portion. A preferred lower limit is 40% and a preferred upper limit is 70%.
In the present specification, the gel fraction means the ratio of the crosslinked adhesive component excluding the non-crosslinked component in the adhesive. The gel fraction is, for example, a pressure-sensitive adhesive whose weight is A is dissolved in a solvent such as ethyl acetate or THF, filtered through a metal mesh or the like, and then the residue on the mesh is dried by heating to remove the solvent by drying. When the weight of the residue is B, it can be calculated by the following formula (1).
Gel fraction (%) = dry residue weight B / adhesive weight A × 100 (1)

The pressure-sensitive adhesive layer, frequency 10 Hz, setting the distortion 0.5%, heating rate 3 ° C. / lower limit of the elastic modulus at 10 ° C. Based on the dynamic viscoelasticity measured by a shear method under the conditions of min is 5 × ¹⁰ 5 Pa It is. When the pressure is less than 5 × 10 ⁵ Pa, even if the dicing tape can be fixed to the semiconductor wafer without causing “floating”, the semiconductor wafer swings due to an impact during dicing, and chipping occurs. A preferred lower limit is 1 × 10 ⁶ Pa, and a more preferred lower limit is 5 × 10 ⁶ Pa.
The upper limit of the elastic modulus is not particularly limited, but about 5 × 10 ⁹ Pa is the practical upper limit in order to achieve the above-described gel fraction.

Moreover, as the adhesive which comprises the said adhesive layer, curable resin composition is suitable. Individual IC chips obtained by dicing a semiconductor wafer provided with a circuit and a through electrode are usually picked up by a needle from the substrate side of the dicing tape and fixed on the die pad. However, the impact when the needle is pushed up may break the IC chip or damage the through electrode. In the dicing tape of the present invention, by using the pressure-sensitive adhesive layer having a gas generating agent that generates gas by stimulation, pick-up can be performed without using a needle, and an IC chip can be obtained very safely. At this time, if a curable resin composition is used as the pressure-sensitive adhesive layer, the IC chip can be more easily peeled off from the dicing tape and picked up by curing after dicing and reducing the adhesive force. Also, by curing the pressure-sensitive adhesive layer prior to the generation of gas, most of the generated gas can be released to the outside of the pressure-sensitive adhesive layer, that is, to the adhesive interface between the pressure-sensitive adhesive layer and the IC chip, and peeling By increasing the pressure, it can be more easily and reliably peeled off.

The curable resin composition includes an acrylic acid alkyl ester-based and / or methacrylic acid alkyl ester-based polymerizable polymer having a radical polymerizable unsaturated bond in the molecule, and a photopolymerization initiator. A photocurable resin composition comprising: an acrylic acid alkyl ester-based and / or methacrylic acid alkyl ester-based polymerizable polymer having a radical polymerizable unsaturated bond in the molecule, and a radical polymerizable polyfunctional oligomer or A thermosetting resin composition comprising a monomer as a curable component and containing a thermal polymerization initiator is preferred.

In order to achieve the above-described elastic modulus at 10 ° C. using such a curable resin composition, for example, an acrylic copolymer containing a segment derived from a monomer whose homopolymer exhibits a high glass transition temperature is used. What is necessary is just to increase the elasticity modulus in a low temperature range using what has a main component. Moreover, you may use the method which raises sclerosis | hardenability further by making a radically polymerizable polyfunctional oligomer or monomer contain as a sclerosing | hardenable component as needed.

However, when the modulus of elasticity in the low temperature region is increased by such a method, the modulus of elasticity in the normal temperature region where the dicing tape and the wafer are bonded is greatly increased, and even if the gel fraction is adjusted. , Uneven followability may be somewhat inferior. When the unevenness followability is inferior, chipping may be observed at the end of the IC chip after dicing.

On the other hand, the curable resin composition which has as a main component the acrylic copolymer containing the segment derived from the isobornyl acrylate segment and the (meth) acrylic-acid alkylester which has a C1-C12 alkyl group. When an object is used, the above-described high elastic modulus can be easily achieved, and particularly high unevenness followability can be achieved even in a normal temperature range. This is presumably because the isobornyl acrylate segment has the effect of increasing the elastic modulus in the low temperature region of the acrylic copolymer, while suppressing the increase in the elastic modulus near room temperature. Therefore, when such a curable resin composition is used, since it is flexible and can exhibit extremely high unevenness followability at the time of bonding, and can be held firmly at the time of dicing, it effectively suppresses the occurrence of chipping. Can do.

The pressure-sensitive adhesive layer made of the above-mentioned photocurable resin composition or thermosetting resin composition is polymerized and cured because the entire pressure-sensitive adhesive layer is uniformly and quickly polymerized and cross-linked by light irradiation or heating. The elastic modulus rises significantly due to, and the adhesive strength is greatly reduced.

The acrylic copolymer has, for example, an isobornyl acrylate segment and a segment derived from a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 12 carbon atoms as a main component, and in the molecule. An acrylic polymer having a functional group (hereinafter referred to as a functional group-containing acrylic polymer) is synthesized in advance, and a compound having a functional group that reacts with the above functional group and a radical polymerizable unsaturated bond (hereinafter, referred to as a functional group). It can be obtained by reacting with a functional group-containing unsaturated compound).

The functional group-containing acrylic polymer is mainly composed of isobornyl acrylate and a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 12 carbon atoms. Accordingly, it can be obtained by copolymerizing with other modifying monomers copolymerizable with these by a conventional method. The weight average molecular weight of the functional group-containing acrylic polymer is usually about 200,000 to 2,000,000.

Examples of the functional group-containing monomer include a carboxyl group-containing monomer such as acrylic acid and methacrylic acid; a hydroxyl group-containing monomer such as hydroxyethyl acrylate and hydroxyethyl methacrylate; and an epoxy group containing glycidyl acrylate and glycidyl methacrylate. Monomers; Isocyanate group-containing monomers such as isocyanate ethyl acrylate and isocyanate ethyl methacrylate; and amino group-containing monomers such as aminoethyl acrylate and aminoethyl methacrylate.

Examples of other modifying monomers that can be copolymerized include various monomers used in general (meth) acrylic polymers such as vinyl acetate, acrylonitrile, and styrene.

As the functional group-containing unsaturated compound to be reacted with the functional group-containing acrylic polymer, the same functional group-containing monomer as described above can be used according to the functional group of the functional group-containing acrylic polymer. For example, when the functional group-containing acrylic polymer has a carboxyl group, an epoxy group-containing monomer or an isocyanate group-containing monomer is used. When the functional group is a hydroxyl group, an isocyanate group-containing monomer is used. When the group is an epoxy group, an amide group-containing monomer such as a carboxyl group-containing monomer or acrylamide is used, and when the functional group is an amino group, an epoxy group-containing monomer is used.

As the content of each segment in the acrylic copolymer, the lower limit of the isobornyl acrylate segment ratio in the total of the isobornyl acrylate segment and the segment derived from the (meth) acrylic acid alkyl ester is 25% by weight. It is. If it is less than 25% by weight, a pressure-sensitive adhesive layer having a high elastic modulus may not be formed. A more preferred lower limit is 35% by weight.
The upper limit of the ratio of isobornyl acrylate is not particularly limited, but it is preferable that the glass transition temperature of the obtained acrylic copolymer is normal temperature (25 ° C.) or lower. If the glass transition temperature of the acrylic copolymer exceeds room temperature (25 ° C.), the adhesive tape of the present invention cannot exhibit adhesiveness at room temperature. Even in the vibration, it is partially peeled off, and dicing cannot be performed accurately.
For example, in the combination with 2-ethylhexyl acrylate segment, the upper limit of the ratio of isobornyl acrylate is 80% by weight, and in the combination with butyl acrylate segment, the upper limit of the ratio of isobornyl acrylate is 70% by weight. is there.

The number of functional groups per molecule of the radical polymerizable polyfunctional oligomer or radical polymerizable polyfunctional monomer is preferably 5 or more. If it is less than 5, curing (crosslinking) of the pressure-sensitive adhesive is insufficient, and the adhesive force may not be sufficiently lowered. The radical polymerizable polyfunctional oligomer or radical polymerizable polyfunctional monomer preferably has a molecular weight of 10,000 or less, more preferably three-dimensional networking of the pressure-sensitive adhesive layer by heating or light irradiation. In order to achieve efficiency, the molecular weight is 5000 or less and the number of radically polymerizable unsaturated bonds in the molecule is 2 to 20.

Examples of such radical polymerizable polyfunctional oligomers or radical polymerizable multifunctional monomers include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol monohydroxy. Examples include pentaacrylate, dipentaerythritol hexaacrylate, and methacrylates similar to those described above. Other examples include 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligomeric ester acrylate, epoxy acrylate, urethane acrylate, and the same methacrylates as described above. These radical polymerizable polyfunctional oligomers or radical polymerizable polyfunctional monomers may be used alone or in combination of two or more.

It is preferable that the said adhesive layer contains a photoinitiator or a thermal-polymerization initiator as needed. When it contains a photopolymerization initiator, it can be photocurable, and when it contains a thermal polymerization initiator, it can be thermosetting.

Examples of the photopolymerization initiator include those activated by irradiation with light having a wavelength of 250 to 800 nm. Examples of such a photopolymerization initiator include acetophenone derivative compounds such as methoxyacetophenone. Benzoin ether compounds such as benzoin propyl ether and benzoin isobutyl ether; ketal derivative compounds such as benzyl dimethyl ketal and acetophenone diethyl ketal; phosphine oxide derivative compounds; bis (η5-cyclopentadienyl) titanocene derivative compounds, benzophenone, Michler's ketone Chlorothioxanthone, todecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexyl phenyl ketone, 2-hydroxymethylphenyl pro Examples thereof include photo radical polymerization initiators such as bread. These photoinitiators may be used independently and 2 or more types may be used together.

Examples of the thermal polymerization initiator include those that decompose by heat and generate an active radical that initiates polymerization and curing. Specific examples include dicumyl peroxide, di-t-butyl peroxide, and t-butyl. Examples include peroxybenzoate, t-butyl hydroperoxide, benzoyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramentane hydroperoxide, and di-t-butyl peroxide. Among these, cumene hydroperoxide, paramentane hydroperoxide, di-t-butyl peroxide, and the like are preferable because of their high thermal decomposition temperature. Although it does not specifically limit as what is marketed among these thermal-polymerization initiators, For example, perbutyl D, perbutyl H, perbutyl P, permenta H (all are the products made from NOF) etc. are suitable. These thermal polymerization initiators may be used independently and 2 or more types may be used together.

The pressure-sensitive adhesive layer preferably further contains a gas generating agent that generates gas upon stimulation.
As described above, each IC chip obtained by dicing the semiconductor wafer needs to be peeled off from the dicing tape and picked up, but once the adhesive layer is in close contact with the protruding portion, Even when a curable resin composition is used as an adhesive, peeling is difficult. By containing a gas generating agent in the pressure-sensitive adhesive layer, gas is generated from the gas generating agent when stimulating the dicing tape at the time of peeling, and at least a part of the adhesive surface can be peeled off to reduce the adhesive force. Peeling can be easily performed.

Although it does not specifically limit as a stimulus for generating gas from the said gas generating agent, For example, light irradiation, such as an ultraviolet-ray and visible light, is suitable. The pressure-sensitive adhesive layer containing such a gas generating agent is preferably capable of transmitting or passing light.
It does not specifically limit as a gas generating agent which generate | occur | produces gas by the said stimulation, For example, an azo compound, an azide compound, etc. are mentioned.

Examples of the azo compound include 2,2′-azobis (N-cyclohexyl-2-methylpropionamide), 2,2′-azobis [N- (2-methylpropyl) -2-methylpropionamide], 2 , 2′-azobis (N-butyl-2-methylpropionamide), 2,2′-azobis [N- (2-methylethyl) -2-methylpropionamide], 2,2′-azobis (N-hexyl) -2-methylpropionamide), 2,2′-azobis (N-propyl-2-methylpropionamide), 2,2′-azobis (N-ethyl-2-methylpropionamide), 2,2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide}, 2,2′-azobis {2-methyl-N- [2- (1-hydroxy) Butyl)] propionamide}, 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2′-azobis [N- (2-propenyl) -2-methylpropionamide 2,2'-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis [2- (2-imidazolin-2-yl) propane] dihydro Chloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] disulfate dihydrolate, 2,2′-azobis [2- (3,4,5,6-tetrahydropyrimidine- 2-yl) propane] dihydrochloride, 2,2′-azobis {2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl] propane} dihydrochloride Id, 2,2'-azobis [2- (2-imidazolin-2-yl) propane], 2,2'-azobis (2-methylpropionamidine) hydrochloride, 2,2'-azobis (2-aminopropane) Dihydrochloride, 2,2′-azobis [N- (2-carboxyacyl) -2-methyl-propionamidine], 2,2′-azobis {2- [N- (2-carboxyethyl) amidine] propane} 2,2′-azobis (2-methylpropionamidooxime), dimethyl 2,2′-azobis (2-methylpropionate), dimethyl 2,2′-azobisisobutyrate, 4,4′-azobis (4-cyanocarbonic acid), 4,4′-azobis (4-cyanopentanoic acid), 2,2′-azobis (2,4,4-trimethylpentane) Etc.
These azo compounds generate nitrogen gas mainly by irradiating light in the ultraviolet region with a wavelength of 365 nm.

The azo compound preferably has a 10-hour half-life temperature of 80 ° C. or higher. If the 10-hour half-life temperature is less than 80 ° C, foaming may occur when the adhesive layer is formed on the base material by drying and drying occurs, or decomposition reactions occur over time, causing the decomposition residue to bleed out. In some cases, gas may be generated over time and the interface with the adherend to be bonded may be lifted. If the 10-hour half-life temperature is 80 ° C. or higher, the heat resistance is excellent, and therefore, use at a high temperature and stable storage are possible.

Examples of the azo compound having a 10-hour half-life temperature of 80 ° C. or higher include an azoamide compound represented by the following general formula (1). In addition to being excellent in heat resistance, the azoamide compound represented by the following general formula (1) is also excellent in solubility in an adhesive polymer such as an acrylic acid alkyl ester polymer, which will be described later, in the adhesive layer. The particles may not exist as particles.

In formula (1), R ¹ and R ² each represent a lower alkyl group, and R ³ represents a saturated alkyl group having 2 or more carbon atoms. R ¹ and R ² may be the same or different.

Examples of the azoamide compound represented by the general formula (1) include 2,2′-azobis (N-cyclohexyl-2-methylpropionamide) and 2,2′-azobis [N- (2-methylpropyl). -2-methylpropionamide], 2,2′-azobis (N-butyl-2-methylpropionamide), 2,2′-azobis [N- (2-methylethyl) -2-methylpropionamide], 2 , 2′-azobis (N-hexyl-2-methylpropionamide), 2,2′-azobis (N-propyl-2-methylpropionamide), 2,2′-azobis (N-ethyl-2-methylpropionamide) Amide), 2,2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide}, 2,2′-azobi {2-methyl-N- [2- (1-hydroxybutyl)] propionamide}, 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2′-azobis [N- (2-propenyl) -2-methylpropionamide] and the like. Among these, 2,2′-azobis (N-butyl-2-methylpropionamide) and 2,2′-azobis [N- (2-propenyl) -2-methylpropionamide] have improved solubility in solvents. It is preferably used because it is particularly excellent.

The azide compound is not particularly limited. For example, 3-azidomethyl-3-methyloxetane, terephthalazide, p-tert-butylbenzazide; glycidyl obtained by ring-opening polymerization of 3-azidomethyl-3-methyloxetane Examples thereof include a polymer having an azido group such as an azide polymer. These azide compounds generate nitrogen gas mainly by irradiating light in the ultraviolet region with a wavelength of 350 nm.

Among these gas generating agents, the azide compound is easily decomposed even by giving an impact and releases nitrogen gas, so that there is a problem that handling is difficult. Furthermore, once the decomposition starts, the azide compound causes a chain reaction and explosively releases nitrogen gas, which cannot be controlled. Therefore, the adherend may be damaged by the explosively generated nitrogen gas. There is also a problem. Due to such problems, the amount of the azide compound used is limited, but sufficient effects may not be obtained with the limited amount used.

On the other hand, unlike the azide compound, the azo compound is extremely easy to handle because it does not generate gas upon impact. In addition, since the chain reaction does not generate gas explosively, the adherend is not damaged, and the generation of gas can be interrupted if the irradiation of ultraviolet rays is interrupted. There is also an advantage that control is possible. Therefore, it is more preferable to use an azo compound as the gas generating agent.

The gas generating agent is preferably dissolved in the pressure-sensitive adhesive layer. Since the gas generating agent is dissolved in the pressure-sensitive adhesive layer, the gas generated from the gas generating agent is efficiently released out of the pressure-sensitive adhesive layer when stimulation is applied. In addition, when the gas generating agent is present as particles in the pressure-sensitive adhesive layer, when light is irradiated as a gas generating stimulus, light is scattered at the particle interface, resulting in low gas generation efficiency. The surface smoothness of the layer may deteriorate. The fact that the gas generating agent is dissolved in the pressure-sensitive adhesive layer can be confirmed by the absence of gas generating agent particles when the pressure-sensitive adhesive layer is observed with an electron microscope.

In order to dissolve the gas generating agent in the pressure-sensitive adhesive layer, a gas generating agent that dissolves in the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer may be selected. When selecting a gas generating agent that does not dissolve in the pressure-sensitive adhesive, for example, the gas generating agent can be dispersed as finely as possible in the pressure-sensitive adhesive layer by using a disperser or using a dispersing agent in combination. preferable. In order to finely disperse the gas generating agent in the pressure-sensitive adhesive layer, the gas generating agent is preferably fine particles, and these fine particles are necessary using, for example, a disperser or a kneading apparatus. Accordingly, finer fine particles are preferable. That is, it is more preferable to disperse the gas generating agent to a state where it cannot be confirmed when the pressure-sensitive adhesive layer is observed with an electron microscope.

The content of the gas generating agent may be appropriately selected depending on the type of the gas generating agent. For example, when an azo compound is used as the gas generating agent, 5 to 50 parts by weight with respect to 100 parts by weight of the adhesive. It is preferable that If the amount is less than 5 parts by weight, a sufficient peeling pressure may not be obtained and peeling may not be possible. If the amount exceeds 50 parts by weight, the solubility may deteriorate and problems such as bleeding may occur. More preferably, it is 15-30 weight part.

In addition to the above components, the above-mentioned pressure-sensitive adhesive layer has various polyfunctionalities that are blended with general pressure-sensitive adhesives such as isocyanate compounds, melamine compounds, and epoxy compounds as desired for the purpose of adjusting the cohesive force as a pressure-sensitive adhesive. May be added as appropriate. Moreover, well-known additives, such as a plasticizer, resin, surfactant, wax, and a fine particle filler, can also be added.

The thickness of the pressure-sensitive adhesive layer may be appropriately selected according to the height of the protruding portion of the IC chip with a through electrode to be manufactured. However, the height of the protruding portion is usually about 10 to 30 μm. The lower limit is 15 μm, and the upper limit is 50 μm. If it is less than 15 μm, depending on the type of IC chip with a through electrode, the protruding portion may penetrate the adhesive layer and cannot be fixed sufficiently. If it exceeds 50 μm, it is not practical and the adhesive layer has a high elastic modulus. However, it may not be able to be fixed sufficiently.

ADVANTAGE OF THE INVENTION According to this invention, the dicing tape which can be used suitably for manufacture of IC chip with a penetration electrode can be provided.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.
(Experimental Example 1-1)
<Preparation of adhesive>
The following compounds were dissolved in ethyl acetate and polymerized by irradiating with ultraviolet rays to obtain an acrylic copolymer having a weight average molecular weight of 700,000.
The resin solid content of 100 parts by weight of the ethyl acetate solution containing the acrylic copolymer thus obtained is reacted by adding 3.5 parts by weight of 2-isocyanatoethyl methacrylate, and further the resin of the ethyl acetate solution after the reaction. For 100 parts by weight of solid content, urethane acrylate (10 functional) (
30 parts by weight of Shin-Nakamura Chemical Co., Ltd. (NK Oligo U324A), 0.5 parts by weight of polyisocyanate, and 5 parts by weight of a photopolymerization initiator (Irgacure 651) were mixed to prepare an ethyl acetate solution of adhesive (1).
Ethyl acrylate 100 parts by weight Acrylic acid 1 part by weight 2-hydroxyethyl acrylate 5 parts by weight Photopolymerization initiator 0.2 part by weight (Irgacure 651, 50% ethyl acetate solution)
Lauryl mercaptan 0.01 parts by weight

In addition, 30 parts by weight of 2,2′-azobis- (N-butyl-2-methylpropionamide) and 2,4-, based on 100 parts by weight of the resin solid content of the ethyl acetate solution of the pressure-sensitive adhesive (1) A pressure-sensitive adhesive (2) containing a gas generating agent was prepared by mixing 3.6 parts by weight of diethylthioxanthone.

<Production of dicing tape>
Apply the ethyl acetate solution of adhesive (1) with a doctor knife so that the dry film thickness is about 30 μm on one side of a 100 μm thick transparent polyethylene terephthalate (PET) film with corona treatment on both sides. The coating solution was dried by heating at 110 ° C. for 5 minutes. Next, a PET film having been subjected to a release treatment was attached to the surface of the pressure-sensitive adhesive (1) layer. Thereafter, static curing was performed at 40 ° C. for 3 days to obtain a dicing tape.

About the adhesive layer of the obtained dicing tape, the gel fraction was measured with the following method.
First, 0.1 g of the pressure-sensitive adhesive constituting the obtained pressure-sensitive adhesive layer was weighed, immersed in an ethyl acetate solvent for 24 hours, filtered through a metal mesh, and the residue on the mesh was heated at 110 ° C. for 2 hours. The solvent was completely removed by drying. The weight of this residue was weighed, and the gel fraction was calculated by the above formula (1). The gel fraction thus obtained was 30%.
About the adhesive layer of the obtained dicing tape, using a viscoelasticity measuring apparatus (made by IT measurement control company, DVA-200), conditions of frequency 10Hz, setting distortion 0.5%, temperature increase rate 3 degrees C / min. When the elastic modulus at 10 ° C. based on dynamic viscoelasticity was measured by a shearing method, it was 1 × 10 ⁵ Pa.

<Preparation of dicing tape having adhesive layer with other gel fraction>
In the preparation of the pressure-sensitive adhesive (1), by adjusting the blending amount of urethane acrylate (10 functional) (manufactured by Shin-Nakamura Chemical Co., Ltd., NK Oligo U324A) and polyisocyanate, the elastic modulus is 1 × 10 ⁵ Pa, gel fraction Five types of dicing tapes having pressure-sensitive adhesive layers having 20%, 40%, 60%, 80%, and 90% were prepared.

(Experimental example 1-2)
In the preparation of the acrylic copolymer, in place of 100 parts by weight of ethyl acrylate, an elastic modulus of 5 × was obtained in the same manner as in Experimental Example 1-1 except that 80 parts by weight of ethyl acrylate and 20 parts by weight of methyl methacrylate were blended. Six types of dicing tapes having pressure-sensitive adhesive layers having 10 ⁵ Pa and gel fractions of 20%, 30%, 40%, 60%, 80%, and 90% were prepared.

(Experimental Example 1-3)
In the preparation of the acrylic copolymer, an elastic modulus of 1 × was obtained in the same manner as in Experimental Example 1-1 except that 70 parts by weight of ethyl acrylate and 30 parts by weight of methyl methacrylate were blended instead of 100 parts by weight of ethyl acrylate. Six types of dicing tapes having pressure-sensitive adhesive layers having 10 ⁶ Pa and gel fractions of 20%, 30%, 40%, 60%, 80%, and 90% were prepared.

(Evaluation)
After dry etching was performed on the Si wafer to open a via hole, an electrode was formed by filling with plating. Next, the surface opposite to the surface on which the circuit was formed was wet etched with hydrofluoric acid. As a result, a semiconductor wafer having a through electrode arranged as shown in FIG. 3 having a diameter of 150 mm, a thickness of 50 μm, and 125 protrusions having a height of 20 μm arranged in rows and columns at intervals of 400 μm was obtained. . This semiconductor wafer has an area of □ 7 × 7 mm that is cut into individual chips after dicing.

The 18 kinds of dicing tapes produced in Experimental Examples 1-1 to 1-3 were attached to the surface of the semiconductor wafer having the through electrodes, and then attached to a dicing apparatus for dicing. After dicing, each cut IC chip with penetrating electrodes was irradiated with ultraviolet rays having an irradiation intensity of 3000 mW / cm ² at 365 nm with spot light from the substrate side of the dicing tape for 0.5 seconds, and then (needle Each IC chip was sucked and picked up (without pushing up).
A series of processes and the obtained IC chip with a through electrode were visually observed and evaluated according to the following criteria.
-Evaluation of dicing property (double-circle): The chip | tip beyond 20 micrometers was not recognized by the IC chip edge part after dicing.
○: No large chip exceeding 30 μm was observed at the end of the IC chip after dicing. ×: Large chip exceeding 30 μm was observed at the end of the IC chip after dicing. Pickup was possible without residue of adhesive ×: Pickup was not possible, cracked, or adhesive remained.

(Experimental example 2-1)
<Preparation of adhesive>
The following compounds were dissolved in ethyl acetate and polymerized by irradiating with ultraviolet rays to obtain an acrylic copolymer having a weight average molecular weight of 700,000.
The resin solid content of 100 parts by weight of the ethyl acetate solution containing the acrylic copolymer thus obtained is reacted by adding 3.5 parts by weight of 2-isocyanatoethyl methacrylate, and further the resin of the ethyl acetate solution after the reaction. 30 parts by weight of urethane acrylate (10 functional) (manufactured by Shin-Nakamura Chemical Co., Ltd., NK Oligo U324A), 0.5 parts by weight of polyisocyanate, 5 parts by weight of photopolymerization initiator (Irgacure 651) with respect to 100 parts by weight of solid content Were mixed to prepare an ethyl acetate solution of the pressure-sensitive adhesive (1).
Isobonyl acrylate 15 parts by weight Butyl acrylate 85 parts by weight Acrylic acid 1 part by weight 2-hydroxyethyl acrylate 5 parts by weight Photopolymerization initiator 0.2 part by weight (Irgacure 651, 50% ethyl acetate solution)
Lauryl mercaptan 0.01 parts by weight

In addition, 30 parts by weight of 2,2′-azobis- (N-butyl-2-methylpropionamide) and 2,4-, with respect to 100 parts by weight of the resin solid content of the ethyl acetate solution of the pressure-sensitive adhesive (2) A pressure-sensitive adhesive (2) containing a gas generating agent was prepared by mixing 3.6 parts by weight of diethylthioxanthone.

<Production of dicing tape>
Apply an ethyl acetate solution of adhesive (2) with a doctor knife so that the dry film thickness is about 30 μm on one side of a 100 μm thick transparent polyethylene terephthalate (PET) film with corona treatment on both sides. The coating solution was dried by heating at 110 ° C. for 5 minutes. Next, a PET film having been subjected to a release treatment was attached to the surface of the pressure-sensitive adhesive (2) layer. Thereafter, static curing was performed at 40 ° C. for 3 days to obtain a dicing tape.

About the adhesive layer of the obtained dicing tape, the gel fraction was measured with the following method.
First, 0.1 g of the pressure-sensitive adhesive constituting the obtained pressure-sensitive adhesive layer was weighed, immersed in an ethyl acetate solvent for 24 hours, filtered through a metal mesh, and the residue on the mesh was heated at 110 ° C. for 2 hours. The solvent was completely removed by drying. The weight of this residue was weighed, and the gel fraction was calculated by the above formula (1). The gel fraction thus obtained was 30%.
About the adhesive layer of the obtained dicing tape, using a viscoelasticity measuring apparatus (made by IT measurement control company, DVA-200), conditions of frequency 10Hz, setting distortion 0.5%, temperature increase rate 3 degrees C / min. When the elastic modulus at 10 ° C. based on dynamic viscoelasticity was measured by a shearing method, it was 1 × 10 ⁵ Pa.

<Preparation of dicing tape having adhesive layer with other gel fraction>
In the preparation of the pressure-sensitive adhesive (1), by adjusting the blending amount of urethane acrylate (10 functional) (manufactured by Shin-Nakamura Chemical Co., Ltd., NK Oligo U324A) and polyisocyanate, the elastic modulus is 1 × 10 ⁵ Pa, gel fraction Five types of dicing tapes having pressure-sensitive adhesive layers having 20%, 40%, 60%, 80%, and 90% were prepared.

(Experimental example 2-2)
In the preparation of the acrylic copolymer, the elastic modulus was 5 × 10 ⁵ Pa, glass, by the same method as in Experimental Example 2-1, except that the blend of isobornyl acrylate / butyl acrylate was 25 parts by weight / 75 parts by weight. Six types of dicing tapes having pressure-sensitive adhesive layers having a transition temperature of 0 ° C. and a gel fraction of 20%, 30%, 40%, 60%, 80%, and 90% were prepared.

(Experimental Example 2-3)
In the preparation of the acrylic copolymer, the elastic modulus was 1 × 10 ⁶ Pa by the same method as in Experimental Example 2-1, except that the blending with isobornyl acrylate / butyl acrylate was 60 parts by weight / 40 parts by weight. Six types of dicing tapes having pressure-sensitive adhesive layers having gel fractions of 20%, 30%, 40%, 60%, 80%, and 90% were prepared.

(Evaluation)
The 18 kinds of dicing tapes produced in Experimental Examples 2-1 to 2-3 were evaluated in the same manner as in Experimental Example 1-1.
The results are shown in Table 2.

ADVANTAGE OF THE INVENTION According to this invention, the dicing tape which can be used suitably for manufacture of IC chip with a penetration electrode can be provided.

It is a schematic diagram explaining the state which fixed the semiconductor wafer in which the circuit and the penetration electrode were provided in the dicing tape of this invention. It is a schematic diagram explaining the state which fixed the semiconductor wafer in which the circuit and the penetration electrode were provided in the conventional dicing tape. It is a schematic diagram which shows the structure of the semiconductor wafer which has the penetration electrode used by evaluation of the experiment example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor wafer 11 Projection part of penetration electrode 2 Dicing tape 21 Base material 22 Adhesive layer

Claims (4)

A dicing tape used for manufacturing an IC chip with a through electrode,
A base material, and a pressure-sensitive adhesive layer having a thickness of 15 to 50 μm laminated on the base material;
The pressure-sensitive adhesive layer has a gel fraction of 30 to 80%, a frequency of 10 Hz, a set strain of 0.5%, and a temperature increase rate of 3 ° C./min. The dicing tape characterized by having a storage elastic modulus of 5 × 10 ⁵ Pa or more. The dicing tape according to claim 1, wherein the pressure-sensitive adhesive layer contains a gas generating agent that generates gas upon stimulation. The dicing tape according to claim 1 or 2, wherein the pressure-sensitive adhesive layer comprises a photo-curable resin composition or a thermosetting resin composition. The pressure-sensitive adhesive layer is mainly composed of an isobornyl acrylate segment and a segment derived from a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 12 carbon atoms, and radically polymerizable unsaturated in the molecule. The dicing tape according to claim 1, 2 or 3, further comprising an acrylic copolymer having a bond.