JP6452416B2 - Wafer processing tape - Google Patents

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

  The dicing die bonding tape must be stored in a refrigerator. However, in the wafer processing tape described in Patent Document 1, support members are provided at both lateral ends of the release film. There was a problem that the cold-retaining property of the circular label portion of the agent layer and the adhesive film was poor, and a large amount of the cold-retaining material had to be used during transportation. Further, since the support member is provided, there is a problem that the weight is increased, the handling property is poor, and the transportation cost is increased.

  Therefore, an object of the present invention is to provide a wafer processing tape that can reduce the generation of label marks, improve the cold insulation, and reduce the weight.

  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 And a support member provided at both ends in the short direction of the release film, wherein the support member has a foam.

  In the wafer processing tape, the release film may have a foam.

  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 this invention, generation | occurrence | production of a label trace can be reduced, and while being able to improve cold preservation property, it can be reduced in weight.

(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.

  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. The support member 14 is a second surface 11b of the release film 11 opposite to the first surface 11a on which the adhesive 12 and the pressure-sensitive adhesive film 13 are provided. It is provided at both ends in the hand direction.

  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 foam of a film in which the adhesive properties and mechanical strength are further improved by partially replacing these materials and these materials. Moreover, the laminated body of the said foam and the film which is not foamed may be sufficient. Polyester (PET, PBT, PEN, PBN, PTT) system, polyolefin (PP, PE) system, copolymer (EVA, EEA, EBA) system, and these materials are also used as non-foamed films. Can be used, and a known film such as a film in which the adhesiveness and mechanical strength are further improved, and a film subjected to a release treatment can be used. Further, it is not always necessary to use a foam for the release film, and a known release film may be used.

By using a foam for the release film, it is possible to improve the cold insulation and to realize weight reduction. The apparent density of the foam is preferably 25 to 800 kg / m ³ . The apparent density is a value measured according to JIS K 7222: 2005.

  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 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)
As the support member 14, for example, an adhesive tape obtained by applying an adhesive to a resin film substrate can be suitably used. As the resin film substrate of the adhesive tape, polyester (PET, PBT, PEN, PBN, PTT) series, polyolefin (PP, PE) series, copolymer (EVA, EEA, EBA) series, and these materials It is possible to use a foam of a film in which the adhesiveness and mechanical strength are further improved. Moreover, the laminated body of the said foam and the film which is not foamed may be sufficient. Polyester (PET, PBT, PEN, PBN, PTT) system, polyolefin (PP, PE) system, copolymer (EVA, EEA, EBA) system, and these materials are also used as non-foamed films. It is possible to use a film that is partially replaced by further improving the adhesion and mechanical strength. There is no limitation in particular about the composition and physical property of the adhesive of an adhesive tape, and what is necessary is just what does not peel from the release film 11 in the winding-up process and storage process of the tape 10. FIG.

By providing the support member 14, when the wafer processing tape 10 is rolled up, 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 traces. Further, by using a foam for the support member, it is possible to improve the cold insulation and to realize weight reduction. The apparent density of the foam is preferably 25 to 800 kg / m ³ . The apparent density is a value measured according to JIS K 7222: 2005.

  When the support member 14 is provided on the second surface 11b side of the release film, the support member 14 is provided on the second surface 11b of the release film 11 with the adhesive layer 12 provided on the first surface 11a. It is preferable to provide in the area | region r from the edge part of the release film 11 to the adhesive bond layer 12 as shown to Fig.1 (a) on the area | region corresponding to an outer side, ie, the 2nd surface 11b. With such a structure, when the tape 10 is wound, the circular label portion 11a of the adhesive film 13 provided on the first surface 13a of the release film 11 and the second surface 11b of the release film 11 are wound. Since the provided support member 14 does not overlap, it is possible to prevent the support member 14 from being marked on the adhesive layer 12 via the circular label portion 13 a of the adhesive film 13.

  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.

  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 ′ thicker than the adhesive agent layer 12.

  Since the supporting member has such a thickness, when the tape 10 is wound up, the adhesive film 13 and the second surface 11b of the release film 11 that overlaps the surface of the adhesive film 13 are in contact with each other. Since a space is formed between them, 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.

  Further, as shown in FIG. 3, a support member 14 ″ in which thin adhesive tapes are laminated may be provided.

The support member 14 preferably has a linear expansion coefficient of 1 × 10 ⁻⁴ / ° C. or less at a room temperature level. When the linear expansion coefficient is larger than 1 × 10 ⁻⁴ / ° C., the temperature is returned to the room temperature at the time of use from the low-temperature state (for example, −20 ° C. to 5 ° C.) during heating in the subsequent process or during storage and transportation When the temperature is changed, the dimensional change is not preferable.

  Further, the support member 14 is preferably made of a material having a certain coefficient of friction with respect to the adhesive film 13 from the viewpoint of preventing winding deviation of the wafer processing tape 10. Thereby, the winding shift of the wafer processing tape 10 can be prevented, and the effect that high-speed winding and the number of windings can be increased can be obtained.

  Moreover, as the support member 14, the adhesive tape which apply | coated the adhesive agent to the colored resin film base material can also 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
A wafer processing tape having support members provided at both ends in the short direction of the release film,
It said support member have a foam,
The apparent density of the foam, the wafer processing tape, which is a 25~800kg / m ^3.   2. The wafer processing tape according to claim 1, wherein the release film has a foam.   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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