JPH05148462A - Pressure-sensitive adhesive tape for fixation of semiconductor wafer - Google Patents

Abstract

PURPOSE:To obtain the subject tape capable of remarkably widening the space between devices by making a radiation-curing pressure-sensitive adhesive layer on one side of a base film in which a pressure-sensitive adhesive-application layer is formed through an adhesive layer on a polyamide-polyether-based copolymer film layer. CONSTITUTION:A radiation-curing pressure-sensitive adhesive layer is made on one side of a laminated base film having a layer-constitution composed of a polyamide-polyether-based copolymer film layer, a pressure-sensitive adhesive-application layer formed through an adhesive layer or directly on the radiation-curing pressure-sensitive adhesive layer side of the base film layer and a transfer-prevention layer on the other side. Thereby, the objective pressure-sensitive adhesive tape for fixation of a semiconductor wafer can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive tape used in the process of manufacturing various semiconductors. More specifically, for example, a patterned wafer is cut into individual patterns and divided into semiconductor elements. The present invention relates to a radiation-curable pressure-sensitive adhesive tape for fixing a semiconductor wafer used at that time.

[0002]

2. Description of the Related Art Conventionally, a pickup method using a radiation-curable adhesive tape has been proposed when performing a dicing process for cutting and separating a semiconductor wafer on which a circuit pattern is formed into element pieces.

This is radiation, for example light such as ultraviolet light,
Alternatively, a method using a pressure-sensitive adhesive tape for fixing a semiconductor wafer, which comprises a base film that transmits ionizing radiation such as an electron beam, and a pressure-sensitive adhesive layer coated on the base film and having a property of being cured by irradiation with radiation. Is. More specifically, the element fixing adhesive force during dicing processing is made to be a strong adhesive force, and after the semiconductor wafer is cut and separated into element small pieces, radiation irradiation is performed from the base film side to cure the radiation curable adhesive layer, This is a system in which the adhesive strength for fixing the element is significantly reduced so that even a large element of 25 mm ² or more can be easily picked up regardless of the size of the small element piece.

According to this method, a radiation-curable compound contained in an adhesive layer of a semiconductor wafer fixing adhesive tape obtained by applying a radiation-curable adhesive on a radiation-transparent substrate film is cured by irradiation with radiation to produce an adhesive. It is based on the principle of imparting a three-dimensional reticulated structure to the agent and remarkably lowering its fluidity and adhesive force.

However, in such an adhesive tape, since the adhesive is hardened by the curing reaction of the radiation-curable compound to give a three-dimensional reticulated structure and the adhesive strength is reduced, the rubber of the adhesive tape used at the time of dicing process. As a result, the elastic elasticity almost disappears at the time of pickup. Therefore, it may not be possible to expand the element gap due to the radial stretching of the pressure-sensitive adhesive tape, which has been conventionally performed.

In order to solve this problem, a soft polyvinyl chloride (PVC) as the center layer of the base film has already been put into practical use, but the polyvinyl chloride is a chlorine-based resin, and moreover is composed of a metal compound. Since such stabilizers and plasticizers are contained, chlorine ions, metal ions, plasticizers, etc. may migrate to cause contamination of the surface of the semiconductor wafer.

Therefore, as disclosed in JP-A-2-215528, a thermoplastic resin having rubber-like elasticity, for example, polybutene-1, polyurethane, polyester elastomer, 1,2-polybutadiene, styrene-isoprene-styrene copolymer A pressure-sensitive adhesive tape has been proposed which uses a hydrogenated product or a laminated film having a styrene-ethylene-butene-styrene copolymer (SEBS) as a central layer as a base film. However, these adhesive tapes also require a necking (film stretching) of the base film itself in order to obtain a large and uniform gap amount of element small pieces required in a pickup device with image recognition even in stretching after irradiation with radiation. At that time, partial elongation due to poor force transmission) and loss of rubber-like elasticity due to deterioration of the base film due to radiation irradiation may occur, which is still insufficient in terms of properties.

When polyamide is used as the base film, the base film causes necking.
When the adhesive tape is stretched, there is a problem that the intervals between the element pieces do not widen. Further, since the absolute elongation is small, it breaks when it is highly stretched, but a material having a large absolute elongation and capable of being highly stretched is not suitable because it tends to narrow the interval between the element pieces when the adhesive tape is stretched.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a semiconductor wafer fixing adhesive tape which solves the above problems. That is, an object of the present invention is to provide a pressure-sensitive adhesive tape for fixing a semiconductor wafer, which can significantly expand the element gap because the pressure-sensitive adhesive tape after radiation irradiation can be stretched without necking or breaking. To do.

[0010]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that a base film having a polyamide-polyether copolymer film layer as a central layer It has been found that the element gap can be greatly expanded during stretching and that it does not break,
The present invention has been completed based on this finding.

That is, the present invention provides a pressure-sensitive adhesive tape for fixing a semiconductor wafer, comprising a radiation-curable pressure-sensitive adhesive layer provided on one side of a substrate film, wherein the substrate film has a polyamide-polyether copolymer film as a central layer. Have layers,
A pressure-sensitive adhesive tape for fixing a semiconductor wafer, which is a laminated film having a pressure-sensitive adhesive coating layer on the side of the radiation-curable pressure-sensitive adhesive layer and a transfer-preventing layer on the other side of the layer via an adhesive layer or directly to this layer. Is provided. Here, the radiation refers to light rays such as ultraviolet rays or ionizing radiation such as electron beams.

The polyamide-polyether copolymer used in the present invention is not only a graft copolymer or a block copolymer, but also an alloy of polyamide and polyether, IP.
A mixed form such as N is also included. The elongation is preferably 150% or more.

The polyamide used in the present invention is a lactam represented by nylon 6 (polycapramide), nylon 11 (polyundecane amide), nylon 12 (polydodecane amide) or a homopolymer containing ω-aminocarboxylic acid as a main component. Main component is diamine and dicarboxylic acid represented by polyamide, copolyamide, nylon 6,6 (polyhexamethylene adipamide), nylon 6,10 (polyhexamethylene sebacamide), nylon 6,12 (capramide), etc. And homopolyamide and copolyamide. At the same time, polyether amide, polyester amide, etc., which are copolymers of amide monomers and monomers other than amide monomers, are also included.

The polyether used in the present invention means a polymer of diols such as polyethylene glycol, polypropylene glycol, polybutylene glycol and polytetramethylene glycol.

In the polymerization of the polyamide-polyether type copolymer of the present invention, one or more dicarboxylic acids such as dodecanedioic acid, terephthalic acid and isophthalic acid may be used in addition to the polyamide component and the polyether component. You may add. To the polyamide-polyether copolymer used in the present invention, it is possible to add usual additives such as a heat resistance stabilizer and a lubricant.

A modified product obtained by adding or substituting a low molecular weight compound such as a maleic acid containing a functional group such as a carboxyl group to the above copolymer, if necessary, and a mixture of the above copolymer and a general-purpose resin such as polyolefin. Conventionally known materials such as these, or a mixture thereof can be used, and the type and mixing ratio of the resin can be arbitrarily selected according to various characteristics such as required characteristics and cost of the base film. Further, a blend film made of a composition obtained by mixing the polyamide-polyether copolymer of the present invention with another resin can be used as the central layer.

The resin for the blend film with the polyamide-polyether copolymer of the present invention is not particularly limited except that it is a resin compatible with the polyamide-polyether copolymer. It is preferable to have radiation transparency and flexibility, for example, low density polyethylene, linear low density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polymethylpentene, ethylene-ethyl acrylate copolymer. Coal, ethylene-methyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl methacrylate copolymer, ionomer, ethylene-propylene-diene copolymer, etc. A known polymer such as a homopolymer or a copolymer of Objects, or other resin and requirements of the substrate film include mixtures of the elastomer, the type of resin in accordance with the circumstances such as cost, it is possible to arbitrarily select the blending ratio at 50 wt% or less. In addition,
It is preferable to blend a resin having excellent adhesiveness with the pressure-sensitive adhesive coating layer and the transfer prevention layer, because delamination is unlikely to occur when the pressure-sensitive adhesive tape is stretched.

As a mixing means for preparing the resin of the present invention, a heating roll, a Banbury mixer, etc. are generally adopted. When the above-mentioned mixing means is used, mixing is easy and reliable, and thus the obtained base film has an effect that the whitening phenomenon does not occur even when it is bent.
Further, a multilayer film of the polyamide-polyether copolymer film of the present invention and a film made of another resin can be used as the center layer.

The resin for the film to be laminated on the homopolymer film or the blend film of the polyamide-polyether copolymer of the present invention is not particularly limited, but it is preferable that the resin is transparent to radiation and has flexibility. For example, a resin for a blend film compatible with a polyamide-polyether copolymer, a conventionally well-known resin such as a resin which is difficult to be compatible but satisfies requirements, or a mixture thereof, a laminated film thereof, or another A mixture of a resin and an elastomer and the like, and the like, the type of resin, the thickness of the polyamide-polyether-based copolymer film or less, the radiation-curable pressure-sensitive adhesive layer depending on various conditions such as required properties, processability, and cost of the base film The side film can be arbitrarily selected.

Incidentally, it is preferable to laminate a polyamide-polyether copolymer, a resin having excellent adhesiveness to the adhesive coating layer or the transfer prevention layer, because delamination is unlikely to occur when the adhesive tape is stretched.

As a method for producing the multi-layer film, a conventionally known co-extrusion method, a laminating method or the like is used. At this time, an adhesive agent is applied between the multi-layer films as is usually carried out in the production of a usual laminated film. May be applied. As such an adhesive, a conventionally known adhesive such as an ethylene-vinyl acetate copolymer or a derivative thereof modified with maleic acid can be used.

The resin for the pressure-sensitive adhesive coating layer on the side to which the radiation-curable pressure-sensitive adhesive is applied, which is used in the present invention, is transparent to radiation, does not easily contaminate the Si wafer, and has an adhesive force with the radiation-curable pressure-sensitive adhesive. Large ones such as ethylene-based ones are preferable, and low density polyethylene, linear low density polyethylene, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene. -Methacrylic acid copolymers, ethylene-acrylic acid copolymers, and the like, which are conventionally known ones, or a mixture thereof, and the like, can be arbitrarily selected depending on the adhesiveness with the radiation-curable pressure-sensitive adhesive used. .. This adhesive coating layer plays a role of strengthening the adhesion between the adhesive and the base film, and prevents contamination of the semiconductor wafer due to peeling of the adhesive from the base film during stretching of the adhesive tape after wafer processing. Contribute to.

The resin for the transfer-preventing layer used in the present invention is preferably, for example, an ethylene-based resin, such as low density polyethylene, linear low density polyethylene, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer. Polymers, ethylene-ethyl methacrylic acid copolymers, ethylene-methacrylic acid copolymers, ethylene-acrylic acid copolymers, and the like, which are conventionally known, or a mixture thereof can be used. This transfer-preventing layer is for preventing blocking of the base film without hindering the elongation property of the pressure-sensitive adhesive tape.

Incidentally, in order to reduce the friction between the adhesive tape and the jig during the stretching of the adhesive tape and prevent the necking of the base film, a low density polyethylene, ethylene-vinyl acetate copolymer, and further ethylene are used as a transfer prevention layer. As the vinyl acetate copolymer, it is preferable to use an ethylene-vinyl acetate copolymer having a vinyl acetate content of 5 wt% or less.

As a method for laminating the center layer and the pressure-sensitive adhesive coating layer or the transfer prevention layer, known methods such as a coextrusion method, a heat fusion method or a laminating method using an adhesive agent can be used. As an adhesive when laminating with an adhesive, ethylene-vinyl acetate copolymer, a maleic acid-modified one thereof, a maleic acid-modified ethylene-α-olefin copolymer, a copolymerized polyester resin, etc. are conventionally known. It is possible to use the adhesive compound of, or a mixture thereof.

The ethylene-vinyl acetate copolymer used as an adhesive or a maleic acid modified product of this copolymer having a vinyl acetate content of 20 wt% or more is preferable because the adhesive strength is large and delamination hardly occurs. A known method such as a co-extrusion method or a laminating method is used for manufacturing the laminated film.

From the viewpoints of strength and elongation characteristics and radiation transparency, the thickness of the base film is usually 30 to 300 μm. The thickness ratio of the central layer of the base film is arbitrarily set according to the required characteristics of the base film, but is usually preferably 30% or more with respect to the total thickness of the base film, 50 to 90.
% Is more preferable, and the provision of both of the pressure-sensitive adhesive coating layer and the transfer prevention layer is more symmetrical than the provision of only one, because the structure of the base film becomes a symmetric system in addition to the above-mentioned, so that the edge of the base film is Does not curl on either side,
There is also an advantage that it is preferable in operation.

When the surface of the substrate film on the side of the transfer prevention layer is textured or coated with a lubricant, blocking is prevented, and necking of the substrate film is prevented by reducing friction between the adhesive tape and a jig when the adhesive tape is stretched. effective.

As the radiation-curable pressure-sensitive adhesive, a conventionally known pressure-sensitive adhesive is used, but at least one selected from the group consisting of a cyanurate compound having a carbon-carbon double bond and an isocyanurate compound per 100 parts by weight of the acrylic pressure-sensitive adhesive. When a pressure-sensitive adhesive containing 10 to 200 parts by weight of a compound and 5 to 100 parts by weight of a linear polyester or polyol urethane acrylate compound having two carbon-carbon double bonds is used, the pressure-sensitive adhesive after irradiation with radiation is used. Since the rubber-like elasticity of the layer can be maintained, the effect of maintaining the rubber-like elasticity (flexibility) of the adhesive tape after irradiation with radiation is particularly large.

When the adhesive tape for fixing a semiconductor wafer of the present invention is cured by irradiation with ultraviolet rays, a photopolymerization initiator such as isopropyl benzoin ether, isobutyl benzoin ether, benzophenone, Michler's ketone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone. , Diethylthioxanthone, Benzyl dimethyl ketal, α-hydroxycyclohexyl phenyl ketone, 2-Hydroxymethylphenyl propane, etc. added to the adhesive layer, the curing reaction proceeds efficiently even if the curing reaction time or UV irradiation amount is small, and the device is fixed. The adhesive strength can be reduced.

If necessary, the surface of a radiation-curable silicon acrylate or silicon methacrylate or an adherend, a semiconductor wafer, is coated with a metal substance in order to appropriately reduce the adhesive strength for fixing the element after irradiation with radiation. Similarly, in order to reduce the adhesion strength of the element fixing to the specially treated surface, compound an ion sequestering agent, tackifier, adhesion control agent, surfactant, etc., or other modifiers and conventional ingredients. You can The thickness of this radiation-curable pressure-sensitive adhesive layer is usually 2 to 50 μm.

[0032]

EXAMPLES The present invention will be described in more detail based on examples. In the following examples, each characteristic was tested and evaluated as follows.

1) Adhesive Strength (g / 25 mm) The magnitude of the adhesive strength for fixing the element before irradiation and the degree of decrease after irradiation were examined. The prepared radiation-curable pressure-sensitive adhesive tape was adhered to a Si wafer having a diameter of 5 inches by JIS-Z0
Based on 237, the adhesive force before and after ultraviolet irradiation was measured (9
Peeling at 0 °, peeling speed 50 mm / min). At this time, the surface state of the wafer bonded to the adhesive tape was a mirror surface state.

2) Element Gap (μm) The size of the element gap during stretching of the adhesive tape and the degree of uniformity in the machine direction / transverse direction were examined. A 5 inch diameter Si wafer fixed to the created radiation curable adhesive tape was fully cut into a size of 3 x 3 mm with a die-saw and cured by UV irradiation, and then a wafer expansion device (air pressure 2.0 kg / c
m) was used to measure the amount of element gap in the longitudinal and transverse directions when the expansion stroke was increased by 10 mm and stretching was performed, and the size and uniformity of the element gap were observed. Here, the element gap amount is
Includes a blade thickness of 40 μm during dicing.

3) Strength of Expanding Adhesive Tape The state of the tape when the expanding stroke was 30 mm was examined. In the same manner as in 2) above, full cut into a size of 3 x 3 mm and expand stroke of 30 mm.
The state of whether or not the adhesive tape was broken when it was raised and stretched was observed.

Examples 1 to 6 and Comparative Examples 1 to 4 A base film having each layer constitution as shown in Tables 1 and 2 was prepared by using an extruder and the following resins AE alone or kneader kneading blend compositions were prepared. Was prepared by (co) extrusion. The thickness of the obtained base film (consisting of the pressure-sensitive adhesive coating layer, the central layer, and the transfer prevention layer) was 100 μm. The pressure-sensitive adhesive coating layer side of the obtained base film was corona-treated, and the thickness of the pressure-sensitive adhesive layer after adhesion after drying was 10 μm.
A pressure-sensitive adhesive was applied so as to obtain a radiation-curable pressure-sensitive adhesive tape.

The resins and adhesives used are shown below. Resin A (polyamide-polyether copolymer): Toray Pebax 3533SNOO Resin B (polyamide-polyether copolymer): Daicel Chemical Co., Ltd. Daiamide PAE 47MS1 EPR (ethylene-propylene-diene copolymer): Nippon Synthetic Rubber EP 51 Resin C (Polyamide): Daicel Chemical Co., Ltd. Daiamide
L1940 Resin D (polyamide): Toray aramid CM104
1 Resin E (Polybutene-1) EVA-10 (Ethylene-Vinyl Acetate Copolymer (Vinyl Acetate Content 10%)): Evatate H2 manufactured by Sumitomo Chemical Co., Ltd.
021F EVA-3 (ethylene-vinyl acetate copolymer (vinyl acetate content 3%)): Mitsubishi Yuka Yucaron-Eva V11
3K LLDPE (linear low-density polyethylene): Tosoh Petrosene 205 Adhesive A: Acrylic adhesive 100 parts by weight Isocyanurate compound 80 parts by weight Urethane acrylate compound 20 parts by weight Photoinitiator 1 part by weight Adhesive B: Acrylic Adhesive 100 parts by weight Cyanurate compound 40 parts by weight Urethane acrylate compound 10 parts by weight

[0038]

When the pressure-sensitive adhesive tape for semiconductor fixing of the present invention is used for cutting a semiconductor wafer or the like, the pressure-sensitive adhesive tape after radiation irradiation can be stretched without necking or breaking, so that the element gap can be greatly reduced. Can be expanded. Therefore, the image recognition of the element piece becomes easy. Therefore, there is an excellent effect that the element can be picked up easily and without damage.

[Table 1]

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[Procedure amendment]

[Submission date] January 26, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

When polyamide is used as the base film, the base film causes necking.
When the adhesive tape is stretched, there is a problem that the intervals between the element pieces do not widen. Further, since the absolute elongation is small, it breaks when it is highly stretched . High absolute elongation and high drawability
There are polyamides, but the problem of necking is not solved ,
This is not suitable because it tends to narrow the gap between element pieces when the adhesive tape is stretched.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

The polyamide used in the present invention is a lactam represented by nylon 6 (polycapramide), nylon 11 (polyundecane amide), nylon 12 (polydodecane amide) or a homopolymer containing ω-aminocarboxylic acid as a main component. Diamines and dicarboxylic acids represented by polyamide, copolyamide, nylon 6,6 (polyhexamethylene adipamide), nylon 6,10 (polyhexamethylene sebacamide), nylon 6,12 ( polyhexamethylene capramide), etc. Examples include homopolyamide and copolyamide whose main component is. At the same time, polyether amide, polyester amide, etc., which are copolymers of amide monomers and monomers other than amide monomers, are also included.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shinichi Ishiwata 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Inventor Kazushige Iwamoto 2-6-1 Marunouchi, Chiyoda-ku, Tokyo No. Furukawa Electric Co., Ltd. (72) Inventor Morikuni Hasebe 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Within Furukawa Electric Co., Ltd.

Claims (1)

[Claims] 1. A pressure-sensitive adhesive tape for fixing a semiconductor wafer, comprising a radiation-curable pressure-sensitive adhesive layer provided on one side of a base film, wherein the base film has a polyamide-polyether copolymer film as a central layer in a layer structure. A semiconductor having a layer, and a laminated film having a pressure-sensitive adhesive coating layer on the side of the radiation-curable pressure-sensitive adhesive layer and a transfer-preventing layer on the other side of the layer via an adhesive layer or directly to the layer. Wafer fixing adhesive tape.