JP5435474B2 - Wafer processing tape - Google Patents

Description

The present invention relates to a wafer processing tape, and more particularly to a wafer processing tape body in which a wafer processing tape having two functions of a dicing tape and a die bonding film is wound around a core.

Recently, a dicing tape for fixing a semiconductor wafer when the semiconductor wafer is cut and separated into individual chips (dicing) and a semiconductor chip that has been cut are bonded to a lead frame, a package substrate, or the like, or stacked. In the package, dicing die bonding tape (wafer processing tape) having two functions of a die bonding film (also referred to as a die attach film) for laminating and bonding semiconductor chips to each other has been developed.

Such wafer processing tapes have been pre-cut in consideration of workability such as attachment to a wafer and attachment to a ring frame during dicing (for example, Patent Document 1). reference).

Examples of pre-cut wafer processing tapes are shown in FIGS. FIG. 1 is a view showing a state in which the wafer processing tape 50 is wound up in a roll shape, FIG. 2 (a) is a plan view of the wafer processing tape 50, and FIG. It is sectional drawing by line BB of (a). The wafer processing tape 50 includes a release film 51, an adhesive layer 52, and an adhesive film 53. The adhesive layer 52 is processed into a circle corresponding to the shape of the wafer, and has a circular label shape. The adhesive film 53 is obtained by removing the peripheral area of the circular portion corresponding to the shape of the ring frame for dicing.
3a and a peripheral portion 53b surrounding the outside. Adhesive layer 52 and adhesive film 5
The circular label portion 53a is laminated with its center aligned, and the circular label portion 53a of the adhesive film 53 covers the adhesive layer 52 and is in contact with the release film 51 around it. .

When dicing the wafer, the release film 51 is peeled from the laminated adhesive layer 52 and the adhesive film 53, and the back surface of the semiconductor wafer W is pasted on the adhesive layer 52, as shown in FIG. The dicing ring frame R is adhesively fixed to the outer peripheral portion of the circular label portion 53a of the adhesive film 53. In this state, the semiconductor wafer W is diced, and then the adhesive film 53 is subjected to a curing process such as ultraviolet irradiation to pick up a semiconductor chip. At this time, since the adhesive film 53 has a reduced adhesive force due to the curing process, the adhesive film 53 is easily peeled off from the adhesive layer 52, and the semiconductor chip is picked up with the adhesive layer 52 attached to the back surface. The adhesive layer 52 attached to the back surface of the semiconductor chip then functions as a die bonding film when the semiconductor chip is bonded to a lead frame, a package substrate, or another semiconductor chip.
JP 2007-2173 A

By the way, as shown in FIGS. 1 and 2, the dicing die bonding tape 50 as described above is a peripheral portion of the adhesive film 53 where the adhesive layer 52 and the circular label portion 53 a of the adhesive film 53 are laminated. Thicker than 53b. For this reason, when wound as a product in a roll shape, the step between the laminated portion of the adhesive layer 52 and the circular label portion 53a of the pressure-sensitive adhesive film 53 and the peripheral portion 53b of the pressure-sensitive adhesive film 53 overlap each other, and a flexible adhesive A phenomenon in which a step is transferred to the surface of the layer 52, that is, a transfer mark (also referred to as a label mark, wrinkle, or winding mark) as shown in FIG.
Will occur. Such a transfer mark is particularly noticeable when the adhesive layer 52 is formed of a soft resin or has a thickness, or when the number of windings of the wafer processing tape 50 is large. When the transfer mark is generated, there is a risk that a defect may occur during processing of the wafer due to poor adhesion between the adhesive layer and the semiconductor wafer.

The object of the present invention is to sufficiently suppress the occurrence of transfer marks on an adhesive layer when a wafer processing tape having an adhesive layer and an adhesive film on a release film is wound into a roll. The object is to provide a wafer processing tape body.

The wafer processing tape according to claim 1 of the present invention is a long release film, an adhesive layer having a predetermined planar shape provided on a first surface of the release film, and the adhesive. A pressure-sensitive adhesive having a label portion having a predetermined planar shape provided to cover the layer and in contact with the release film around the adhesive layer, and a peripheral portion surrounding the outside of the label portion In a wafer processing tape body obtained by winding a wafer processing tape having a film around a cylindrical core, the cylindrical diameter of both ends of the cylinder of the core has a large diameter portion larger than the diameter of the central portion of the cylinder. To

The large diameter part may be formed by grinding the central part of the cylinder, or may be formed of a support member having an adhesive layer. Furthermore, the large diameter part adhesion layer may be formed on both surfaces of the support member.

According to the wafer processing tape body of the present invention, it is possible to obtain an effect of sufficiently suppressing the generation of transfer marks on the adhesive layer.

It is a perspective view of the tape for wafer processing which concerns on embodiment of this invention. (A) is a top view of the tape for wafer processing which concerns on embodiment of this invention, (b) is sectional drawing by line BB of (a). It is a perspective view of the core which concerns on embodiment of this invention. It is a perspective view of the core which concerns on other embodiment of this invention. (A) is a perspective view of the tape body for wafer processing which concerns on embodiment of this invention, (b) is sectional drawing by line AA of (a). It is sectional drawing which shows the state by which the tape for wafer processing and the ring frame for dicing were bonded together. It is a schematic diagram for demonstrating the malfunction of the conventional tape for wafer processing.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1A is a plan view of a wafer processing tape (dicing / die bonding tape) according to an embodiment of the present invention,
FIG.1 (b) is sectional drawing by line BB of Fig.1 (a).

As shown in FIGS. 1A and 1B, the wafer processing tape 50 includes a long release film 51, an adhesive layer 52, and an adhesive film 53.

The adhesive layer 52 is provided on the first surface of the release film and has a circular label shape corresponding to the shape of the wafer. The adhesive film 53 covers the adhesive layer 52, and the adhesive layer 5
2 has a circular label portion 53a provided so as to come into contact with the release film, and a peripheral portion 53b surrounding the outside of the circular label portion 53a. The peripheral part 53b includes a form that completely surrounds the outer side of the circular label part 53a and a form that does not completely surround as illustrated. The circular label portion 53a has a shape corresponding to a ring frame for dicing. The wafer processing tape 50 is wound into a roll shape around the core 1 shown in FIGS.
The wafer processing tape body 60 shown in FIG.

  Hereafter, each component of the tape body 60 for wafer processing of this embodiment is demonstrated in detail.

(Release film)
As the release film 51 used for the wafer processing tape 50 of the present invention, a polyethylene terephthalate (PET) -based, polyethylene-based film, or other well-known film such as a film subjected to a release treatment can be used. The thickness of the release film is not particularly limited and may be appropriately set, but is preferably 25 to 50 μm.

(Adhesive layer)
As described above, the adhesive layer 52 of the present invention is formed on the first surface 51a of the release film 51, and has a circular label shape corresponding to the shape of the wafer.

The adhesive layer 52 is attached to the back surface of the chip when the chip is picked up after the semiconductor wafer or the like is bonded and diced, and is used as an adhesive for fixing the chip to the substrate or the lead frame. Is. As the adhesive layer 52, an adhesive or the like containing at least one selected from an epoxy resin, an acrylic resin, and a phenol resin can be preferably used. In addition, a polyimide resin or a silicone resin can also be used. The thickness may be appropriately set, but is preferably about 5 to 100 μm.

(Adhesive film)
As described above, the adhesive film 53 has the circular label portion 53a corresponding to the shape of the ring frame for dicing, and the peripheral portion 53b surrounding the outside. Such an adhesive film can be formed by removing the peripheral region of the circular label portion 53a from the film-like adhesive by precut processing.

The adhesive film 53 is not particularly limited, and has a sufficient adhesive force so that the wafer does not peel when dicing the wafer, and can be easily peeled from the adhesive layer when picking up the chip after dicing. Any material that exhibits low adhesive strength may be used. For example, what provided the adhesive layer in the base film can be used conveniently.

The base film of the adhesive film 53 can be used without particular limitation as long as it is a conventionally known base film. However, when a radiation curable material is used as the adhesive layer described later, the radiation transparency is used. It is preferable to use one having

For example, as the material, polyethylene, polypropylene, ethylene-propylene copolymer, polybutene-1, poly-4-methylpentene-1, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic Α-olefin homopolymer or copolymer such as acid methyl copolymer, ethylene-acrylic acid copolymer, ionomer or a mixture thereof, polyurethane, styrene-ethylene-butene or pentene copolymer, polyamide-polyol Listed are thermoplastic elastomers such as copolymers, and mixtures thereof. Further, the base film may be a mixture of two or more materials selected from these groups, or may be a single layer or a multilayer. The thickness of the base film is not particularly limited, and may be set as appropriate.
0 μm is preferable.

The resin used for the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film 53 is not particularly limited, and a known chlorinated polypropylene resin, acrylic resin, polyester resin, polyurethane resin, epoxy resin or the like used for the pressure-sensitive adhesive is used. can do. It is preferable to prepare an adhesive by appropriately blending an acrylic adhesive, a radiation polymerizable compound, a photopolymerization initiator, a curing agent and the like into the resin of the adhesive layer 53. The thickness of the pressure-sensitive adhesive layer 53 is not particularly limited and may be appropriately set, but is preferably 5 to 30 μm.

A radiation-polymerizable compound can be blended in the pressure-sensitive adhesive layer to facilitate peeling from the adhesive layer by radiation curing. As the radiation polymerizable compound, for example, a low molecular weight compound having at least two photopolymerizable carbon-carbon double bonds in a molecule that can be three-dimensionally reticulated by light irradiation is used.

Specifically, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4-butylene glycol diacrylate, 1,6 hexanediol diacrylate Acrylate, polyethylene glycol diacrylate, oligoester acrylate, and the like are applicable.

In addition to the above acrylate compounds, urethane acrylate oligomers can also be used. The urethane acrylate oligomer includes a polyol compound such as a polyester type or a polyether type, and a polyvalent isocyanate compound (for example, 2, 4
Terminal obtained by reacting tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane 4,4-diisocyanate, etc. An acrylate or methacrylate having a hydroxyl group on an isocyanate urethane prepolymer (for example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, polyethylene glycol acrylate, polyethylene glycol methacrylate, etc.) It is obtained by reacting. The pressure-sensitive adhesive layer may be a mixture of two or more selected from the above resins.

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

(core)
The wafer processing tape 50 is rolled up to a length desired by the user and shipped as a product, or is wound into a roll in an amount corresponding to the number of dicing and die bonding tapes requested by the user. Shipped. 3 is the starting point when winding in a roll shape.
And the core 1 shown in FIG. A double-sided tape is affixed to the core 1, and the location of the double-sided tape becomes the starting point of the wafer processing tape 50.

As an example of the core 1 according to the present invention, as shown in FIG. 3, the core 1 is a cylindrical core body 2.
And the large-diameter portion 3. The large diameter portion is provided at both ends of the core body 2 and the core body 2
0.002 mm to 3.0 mm thicker than the diameter. In the case of the example shown in FIG. 3, the core 1 is manufactured in accordance with the diameter of the large-diameter portion, and the core main body portion 2 is formed by grinding other than both end portions later. Grinding may be omitted. A wafer processing tape body 60 shown in FIG. 5 is obtained by attaching a double-sided tape to the core main body 2 and / or the large diameter portion 3 of the core 1 and winding the wafer processing tape 50 thereon.

In the example of FIG. 4, the entire core is manufactured according to the diameter of the core body, and the large diameter portion 3 is formed by winding the adhesive tape 4 around both ends of the core body 2 later. In the case of the example shown in FIG. 4, it is easy to adjust the diameter of the large diameter portion 3 by the tape thickness and / or the number of stacked layers.

In addition, it is good also considering the adhesive tape in the example of FIG. 4 as a double-sided adhesive tape. By configuring in this way, there is an advantage that the double-sided tape used when winding the wafer processing tape 50 can be omitted.

As shown in FIG. 5B, the portion where the adhesive layer 52 and the circular label portion 53 a of the adhesive film 53 are laminated is thicker than the peripheral portion 53 b of the adhesive film 53. For this reason, when wound as a product in a roll shape, the step between the laminated portion of the adhesive layer 52 and the circular label portion 53a of the pressure-sensitive adhesive film 53 and the peripheral portion 53b of the pressure-sensitive adhesive film 53 overlap each other, and a flexible adhesive A phenomenon in which a step is transferred to the surface of the layer 52, that is, a transfer mark (also referred to as a label mark, a wrinkle, or a winding mark) as shown in FIG. 7 occurs. Such transfer marks are particularly noticeable when the adhesive layer 52 is formed of a soft resin or has a thickness, or when the number of windings of the tape 50 is large. When the transfer mark is generated, there is a risk that a defect may occur during processing of the wafer due to poor adhesion between the adhesive layer and the semiconductor wafer.

By providing the large-diameter portion 3 in the core 1 for such a problem, the winding pressure applied to the tape when the wafer processing tape 50 is wound around a roll is dispersed or collected in the large-diameter portion 3. Therefore, the formation of transfer marks on the adhesive layer 52 can be suppressed.

The width of the large diameter portion 3 is from the end of the release film 51 as shown in FIG.
It is preferable to provide in the area up to. With such a structure, when the wafer processing tape 50 is wound, the circular label portion 53a of the adhesive film 53 provided on the first surface of the release film 51 and the large diameter portion do not overlap. The adhesive layer 52 is prevented from being marked with the large-diameter portion 3.

As thickness of the large diameter part 3, 0.001 mm-1.5 mm are desirable. In other words, the diameter of the large diameter portion 3 is preferably in the range of 0.002 mm to 3.0 mm. Thickness 0.001mm
The reason why the above is desirable is that an effect can be obtained if the thickness is equal to or greater than the thickness of the adhesive layer 52, and the reason why 1.5 mm or less is desirable is for wafer processing when the thickness is greater than 1.5 mm. This is because when the tape 50 is wound around the core 1, the wafer processing tape 50 is likely to fall toward the core body 2, causing problems such as collapse of the winding state and wrinkles.

1: Core 2: Core body part 3: Large diameter part 4: Adhesive tape 50: Wafer processing tape 51: Release film 52: Adhesive layer 53: Adhesive film 53a: Circular label part 53b: Peripheral part 60: Wafer processing Tape body

Claims (2)

A long release film; an adhesive layer having a predetermined planar shape provided on the first surface of the release film; and covering the adhesive layer and surrounding the adhesive layer A wafer processing tape having a label portion having a predetermined planar shape provided in contact with a release film and an adhesive film having a peripheral portion surrounding the outside of the label portion is formed into a cylindrical core. in the wound for wafer processing tape body, the cylindrical diameter of the cylindrical end portions of the core have a large thick portion than the diameter of the cylindrical central portion, the large-diameter portion is, on both ends of the cylindrical core body portion A tape body for wafer processing, which is formed by winding a support member having an adhesive layer . The tape body for wafer processing according to claim 1 , wherein the adhesive layer of the large diameter portion is formed on both surfaces of the support member .

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