JP2016111159A - Tape for wafer processing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tape for wafer processing capable of reducing occurrence of a label trace and successfully performing a step of sticking a tape to a wafer.SOLUTION: A tape for wafer processing comprises: a long mold releasing film 11; an adhesive layer 12 having a prescribed planar shape and provided on a first surface of the mold releasing film 11; an adhesive film 13 covering the adhesive layer 12 and including a label part 13a having the prescribed planar shape and provided so as to come into contact with the mold releasing film 11 around the adhesive layer 12 and a peripheral part 13b provided so as to surround the outside of the label part 13a; and a support member 14 provided at both ends in a short direction of the mold releasing film 11 and in the region not overlapping the label part 13a region in contact with the mold releasing film 11 on the first surface side of the mold releasing film 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wafer processing tape, and more particularly to a wafer processing tape having two functions of a dicing tape and a die bonding film.

  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. As a package, a dicing die bonding tape having two functions of a die bonding film (also referred to as a die attach film) for laminating and adhering semiconductor chips has been developed.

  Some dicing / die bonding tapes have been pre-cut in consideration of workability such as attachment to a wafer and attachment to a ring frame during dicing.

  Examples of the pre-cut processed dicing die bonding tape are shown in FIGS. 4 is a view showing a state where the dicing die bonding tape is wound up in a roll shape, FIG. 5A is a plan view of the dicing die bonding tape, and FIG. 5B is a view showing FIG. It is sectional drawing by line BB of (a). The dicing die bonding 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. As shown in the drawing, the adhesive film 53 includes a circular label portion 53a and a peripheral portion 53b surrounding the outside. Have. The adhesive layer 52 and the circular label portion 53a of the pressure-sensitive adhesive film 53 are laminated with their centers aligned, and the circular label portion 53a of the pressure-sensitive adhesive film 53 covers the adhesive layer 52 and is released from the periphery thereof. It is in contact with the film 51.

  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.

  By the way, in the dicing die bonding tape 50 as described above, the portion where the adhesive layer 52 and the circular label portion 53a of the adhesive film 53 are laminated is thicker than the peripheral portion 53b of the adhesive film 53. Therefore, when the product is wound into a roll, the step between the adhesive layer 52 and the circular label portion 53a of the pressure-sensitive adhesive film 53 and the peripheral portion 53a of the pressure-sensitive adhesive film 53 overlap each other, so that the 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.

  In order to solve such a problem, the release film is on the second surface opposite to the first surface on which the adhesive layer and the pressure-sensitive adhesive film are provided, and the release film is short. Wafer processing tapes having support members at both ends in the direction have been developed (see, for example, Patent Document 1). Since such a wafer processing tape is provided with a support member, when the wafer processing tape is wound up in a roll shape, the winding pressure applied to the tape is dispersed or collected on the support member. Therefore, it is possible to suppress the formation of transfer marks on the adhesive layer.

Japanese Patent No. 4360653

  By the way, as shown in FIG. 8, a wafer processing tape (dicing / die bonding tape) is generally peeled off from a laminate comprising an adhesive layer 52 and a circular label portion 53a of an adhesive film, as shown in FIG. Affixed to W (affixing process). In the affixing process, peeling of the laminate composed of the adhesive layer 52 and the circular label portion 53a is promoted by conveying the release film 51 while being folded back in the peeling direction by the wedge-shaped peeling member 101 of the laminating apparatus. Only the laminate is sent forward. At this time, the wafer W and the wafer ring R are installed on the work table 102 on the lower front side, and the laminated body is sent out to the upper side thereof. A pressure roller 103 is provided above the wafer W, whereby the adhesive layer 52 is bonded to the wafer W, and the circular label portion 53a of the adhesive film around the adhesive layer 52 is a wafer ring R. Is pasted. Thus, since the wafer processing tape is folded back particularly in the acute angle direction at the wedge-shaped peeling member 101 portion of the bonding apparatus, what is the first surface on which the adhesive layer and the adhesive film of the release film 51 are provided? The opposite second surface side is locally pressed strongly against the wedge-shaped peeling member 101.

  In the wafer processing tape described in Patent Document 1, the support member is provided on the second surface opposite to the first surface on which the adhesive layer and the adhesive film of the release film 51 are provided. As the support member, generally, an adhesive tape obtained by applying an adhesive to a resin film substrate is used. Therefore, when the adhesive layer and the circular label portion of the wafer processing tape described in Patent Document 1 are bonded to the wafer and the wafer ring, the adhesive member of the support member is attached to the wedge-shaped peeling member 101. There was a problem that it might adhere. When bonding is performed in a state in which the adhesive material of the support member is attached to the wedge-shaped peeling member 101 of the bonding apparatus, the wafer processing tape is attached to the adhesive material attached to the wedge-shaped peeling member 101 of the bonding apparatus. Is caught, and the laminate of the adhesive layer 52 and the circular label portion 53a cannot be sent out successfully.

  Therefore, an object of the present invention is to provide a wafer processing tape that can reduce the generation of label marks and can satisfactorily perform the process of attaching to a wafer.

  In order to solve the above problems, a wafer processing tape according to the present invention includes a long release film, and an adhesive layer having a predetermined planar shape provided on the first surface of the release film. A label portion having a predetermined planar shape that covers the adhesive layer and is in contact with the release film around the adhesive layer, and a peripheral portion that surrounds the outside of the label portion A first film side of the release film, provided with the adhesive layer and the pressure-sensitive adhesive film, and provided at both lateral ends of the release film, And a support member provided in a region that does not cover the region of the label portion that contacts the release film.

  In the semiconductor processing tape, the support member is preferably provided continuously along the longitudinal direction of the release film.

  Moreover, it is preferable that the said support member has the thickness more than the thickness of the said adhesive bond layer in the said tape for semiconductor processing.

  In the semiconductor processing tape, the support member preferably has a laminated structure of two or more layers.

  According to the present invention, the generation of label marks can be reduced, and the step of attaching to a wafer can be favorably performed.

(A) is a top view of the tape for wafer processing which concerns on embodiment of this invention, (b) is sectional drawing by line AA of (a). It is sectional drawing of the tape for wafer processing which concerns on other embodiment of this invention. It is sectional drawing of the tape for wafer processing which concerns on further another embodiment of this invention. It is a perspective view of the conventional wafer processing tape. (A) is a top view of the conventional tape for wafer processing, (b) is sectional drawing by line BB 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. It is a schematic diagram for demonstrating the sticking process to the wafer of the conventional wafer processing tape.

  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, and FIG. 1B is a cross-sectional view taken along line AA in FIG. is there.

  As shown in FIGS. 1A and 1B, the wafer processing tape 10 includes a long release film 11, an adhesive layer 12, an adhesive film 13, and a support member 14.

  The adhesive layer 12 is provided on the first surface of the release film and has a circular label shape corresponding to the shape of the wafer. The pressure-sensitive adhesive film 13 covers the adhesive layer 12 and has a circular label portion 13a provided so as to come into contact with the release film around the adhesive layer 12, and a periphery surrounding the outside of the circular label portion 13a. Part 13b. The peripheral portion 13b includes a form that completely surrounds the outer side of the circular label portion 13a and a form that is not completely surrounded as illustrated. The circular label portion 13a has a shape corresponding to a ring frame for dicing. And the supporting member 14 is the 1st surface 11a in which the adhesive 12 and the adhesive film 13 of the release film 11 were provided, and the transversal direction both ends of the release film 11 of the adhesive bond layer 12 It is provided in a region that does not cover the region of the circular label portion 13 a that contacts the release film 11.

  Hereafter, each component of the tape 10 for wafer processing of this embodiment is demonstrated in detail.

(Release film)
As the release film 11 used for the wafer processing tape 10 of the present invention, polyester (PET, PBT, PEN, PBN, PTT) type, polyolefin (PP, PE) type, copolymer (EVA, EEA, EBA) It is possible to use a film having a further improved adhesiveness and mechanical strength by partially replacing these materials and these materials. Moreover, the laminated body of these films may be sufficient.

  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 12 of the present invention is formed on the first surface 11a of the release film 11 and has a circular label shape corresponding to the shape of the wafer.

  The adhesive layer 12 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 12, an adhesive 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 13 of the present invention has the circular label portion 13a corresponding to the shape of the ring frame for dicing, and the peripheral portion 13b surrounding the outside. Such an adhesive film can be formed by removing the peripheral region of the circular label portion 13a from the film-like adhesive by precut processing.

  The adhesive film 13 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 13 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, but is preferably 50 to 200 μm.

The resin used for the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film 13 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 13. The thickness of the pressure-sensitive adhesive layer 13 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-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diene). A terminal isocyanate urethane prepolymer obtained by reacting isocyanate, 1,4-xylylene diisocyanate, diphenylmethane 4,4-diisocyanate, etc.) with an acrylate or methacrylate having a hydroxyl group (for example, 2-hydroxyethyl) Acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, polyethylene glycol acrylate, polyethylene glycol methacrylate, etc.) Obtained by the reaction.
The pressure-sensitive adhesive layer 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.

(Support member)
The support member 14 is the first surface 11a of the release film 11 on which the adhesive 12 and the pressure-sensitive adhesive film 13 are provided, and both ends of the release layer 11 of the adhesive layer 12 in the short-side direction. An area that does not cover the area of the circular label portion 13a in contact with the release film 11 is provided on the peripheral portion 13b in FIG. Thus, by providing the support member 14, when the wafer processing tape 10 is wound into a roll, the winding pressure applied to the tape can be dispersed or collected on the support member 14. It is possible to suppress the formation of transfer marks on the agent layer 12.

  Here, the region that does not cover the region of the circular label portion 13 a that contacts the release film 11 is a region outside the end of the circular label portion 13 a in the short direction of the release film 11, that is, the region of the release film 11. These are both ends in the short direction, and are regions from the end of the circular label portion 13 a to the end in the short direction of the release film 11 in the short direction of the release film 11. Therefore, the support member 14 may be provided across the release film 11 and the peripheral portion 13b exposed between the circular label portion 13a and the peripheral portion 13b.

  By providing the support member 14 on the first surface 11a on which the adhesive 12 and the adhesive film 13 are provided, it is not necessary to provide the support member 14 on the second surface 11b opposite to the first surface 11a. When the circular label portion 13a is bonded to the wafer W and the wafer ring R, the support member 14 does not contaminate the wedge-shaped peeling member 101 (see FIG. 8) of the bonding apparatus. For this reason, it is possible to satisfactorily perform the process of attaching the wafer.

  As the thickness of the support member 14, the thickness corresponding to the step between the laminated portion of the adhesive layer 12 and the circular label portion 13 a of the adhesive film 13 and the peripheral portion 13 b of the adhesive film 13 on the release film 11. That is, it may be the same as or more than that of the adhesive layer 12. FIG. 2 is a cross-sectional view showing an example of a support member 14 ′ that is thicker than the adhesive layer 12.

  When the supporting member has such a thickness, when the wafer processing tape 10 is wound up, the adhesive film 13 and the second surface 11b of the release film 11 overlapping the surface thereof are in contact with each other, or Since a space is formed between them without contact, the second surface 11 b of the release film 11 is not strongly pressed against the flexible adhesive layer 12 via the adhesive film 13. Therefore, generation of transfer marks can be more effectively suppressed.

  The support member 14 can be provided intermittently or continuously along the longitudinal direction of the release film 11, but from the viewpoint of more effectively suppressing the generation of transfer marks, the longitudinal direction of the base film 11. It is preferable to provide continuously along.

  The support member 14 of the present invention has a linear expansion coefficient of 300 ppm / ° C. or less. For example, the wafer processing tape is kept at a low temperature of about −20 ° C. to 5 ° C. during storage and transportation, and when the adhesive layer of the wafer processing tape is bonded to the wafer, an adhesive is used. In order to increase the adhesiveness by heat softening, the wafer processing tape is placed in an environment with a large temperature change, for example, heat bonding at about 70 to 80 ° C. is performed on a heater table. When the dimension of the support member 14 changes due to temperature change, air enters between the release film 11 and the adhesive film 13 and between the adhesive layer 12 and the adhesive film 13 to generate voids. A bonding failure may occur, which may result in a decrease in yield in the subsequent wafer dicing process, tape expanding process, chip pick-up process, and mounting process. In the present invention, by using a support member having a low coefficient of linear expansion of 300 ppm / ° C. or less, generation of transfer marks on the adhesive layer 12 is sufficiently suppressed, and support is also provided in an environment where the temperature changes greatly. The dimensional change of the member 13 is small, and the generation of voids can be suppressed.

  In order to more effectively suppress the generation of transfer marks and voids, the linear expansion coefficient of the support member 14 is preferably 150 ppm / ° C. or less, and more preferably 70 ppm / ° C. or less. The lower limit of the linear expansion coefficient is not particularly limited, and is usually 0.1 ppm / ° C.

In the present invention, the coefficient of linear expansion refers to the rate at which the spatial extent of an object increases when the temperature is changed under constant pressure. When the temperature is T and the solid length is L, the linear expansion coefficient α is given by the following equation.
α = (1 / L) ・ (∂L / ∂T)

The measurement of the linear expansion coefficient in the present invention is, for example, based on JIS K7197, a linear expansion coefficient test method by thermomechanical analysis of plastic, using a thermomechanical analyzer (TMA), 15 mm in length and 5 mm in width. A sample cut at a distance between chucks of 10 mm is attached, and measurement can be performed under the conditions of a tensile load of 10 g, a heating rate of 5 ° C./min, and a measurement temperature range of −20 ° C. to 50 ° C. in an N ₂ gas atmosphere.

  As the support member 14, for example, an adhesive tape obtained by applying an adhesive to a resin film substrate can be suitably used. By sticking such an adhesive tape to predetermined positions of both end portions of the second surface 11b of the release film 11, the wafer processing tape 10 of this embodiment can be formed.

The base resin of the adhesive tape is not particularly limited as long as it satisfies the range of the linear expansion coefficient and can withstand the winding pressure, but has heat resistance, smoothness, and availability. From the viewpoint, it is preferable to select from polyethylene terephthalate (PET), polypropylene, and high-density polyethylene.
There is no limitation in particular about the composition and physical property of an adhesive of an adhesive tape, and what is necessary is just what does not peel in the winding-up process and storage process of the tape 10. FIG.

  Further, as the support member 14, a colored support member may be used. By using such a colored support member, the type of tape can be clearly identified when the wafer processing tape is wound into a roll. For example, by changing the color of the colored support member 14 depending on the type and thickness of the wafer processing tape, the type and thickness of the tape can be easily identified, and the occurrence of human error is suppressed and prevented. can do.

10: Wafer processing tape 11: Release film 12: Adhesive layer 13: Adhesive film 13a: Circular label part 13b: Peripheral parts 14, 14 ', 14 ": Support member

Claims (4)

A long release film,
An adhesive layer having a predetermined planar shape provided on the first surface of the release film;
A label portion having a predetermined planar shape so as to cover the adhesive layer and contact the release film around the adhesive layer; and a peripheral portion surrounding the outside of the label portion; An adhesive film having
The first side of the release film on which the adhesive layer and the pressure-sensitive adhesive film are provided, and provided at both ends in the short direction of the release film, and in contact with the release film A wafer processing tape, comprising: a support member provided in an area that does not cover the area of the label portion.   The wafer processing tape according to claim 1, wherein the support member is continuously provided along a longitudinal direction of the release film.   The wafer processing tape according to claim 1, wherein the support member has a thickness equal to or greater than a thickness of the adhesive layer.   4. The wafer processing tape according to claim 1, wherein the support member has a laminated structure of two or more layers. 5.

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