JP2013089823A - Wafer processing tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an adhesive layer from being peeled from a cohesive layer of an adhesive tape.SOLUTION: There is provided a wafer processing tape 1 in which a peeling film 2, an adhesive layer 3, a cohesive layer 41, and a base material film 42 are laminated in this order, and an adhesive tape 4 including the base material film and the cohesive layer covers the adhesive layer and being in contact with the peeling film around the adhesive layer. A marking M is formed so as to straddle a boundary line R between the adhesive layer and the cohesive layer from the base material film side on the adhesive layer, and the adhesive layer and the cohesive layer are fused or welded by the marking.

Description

  The present invention relates to a wafer processing tape, and more particularly to a wafer processing tape used for dicing and picking up a semiconductor wafer.

  When cutting a semiconductor wafer into individual semiconductor chips, a "wafer" that has both functions of a dicing tape for fixing the semiconductor wafer and a die bonding film for bonding the cut semiconductor chip to a substrate or the like Processing tapes "have been developed. The wafer processing tape is mainly composed of a release film, an adhesive tape that functions as a dicing tape, and an adhesive layer that functions as a die bonding film.

In recent years, in the field of electronic devices such as memories for portable devices, further reduction in thickness and increase in capacity have been demanded. For this reason, there is an increasing demand for a mounting technique for stacking semiconductor chips having a thickness of 50 [μm] or less in multiple stages.
In response to such a demand, the above wafer processing tape has been developed and disclosed, which can be thinned and has the flexibility to be able to embed irregularities on the circuit surface of a semiconductor chip (for example, (See Patent Documents 1 and 2).

  Wafer processing tape is generally larger than the size of a semiconductor wafer but not touching the ring frame, and is punched from the adhesive layer side to the interface between the adhesive layer and the adhesive layer. At the time of bonding, the wafer is mounted on a semiconductor wafer and a ring frame that supports it by a wafer mounter, and is cut into a circle on the ring frame.

Recently, in consideration of the above workability, the wafer processing tape is pre-cut without being cut on the ring frame. “Pre-cut processing” means that the adhesive tape (adhesive layer is formed on the base film) is punched in advance. Specifically, the base film and the adhesive layer are made of a ring. It is a size that can be bonded to the frame and does not protrude from the ring frame, and is punched into a circle.
If a wafer processing tape that has been subjected to pre-cut processing is used, the wafer processing tape 1 punched into a circle is peeled off from the release film 2 by the release wedge 101 in the bonding process to the semiconductor wafer W by the wafer mounter. After getting the chance, the bonding roller 103 is bonded to the semiconductor wafer W and the ring frame 5 (see FIG. 3), and the process of cutting the adhesive tape on the ring frame can be omitted. You can also eliminate damage to the frame.

  After that, the semiconductor wafer is diced to produce a plurality of semiconductor chips, and the peeling strength (adhesive strength) between the adhesive layer and the adhesive layer is obtained by irradiating radiation from the base film side of the adhesive tape. After sufficiently lowering, the base film of the adhesive tape is expanded to pick up a semiconductor chip. “Radiation” refers to ionizing radiation such as light rays such as ultraviolet rays or electron beams.

By the way, the multifunction, thinning, and complexity of semiconductor devices have progressed, and as a result, the adhesive layer of wafer processing tape has a variety that can be applied to individual semiconductor devices, film thickness, precision of dimensions of each part, etc. Is now required.
On the other hand, the shapes of the wafer and the ring frame have already been established, and the adhesive layer is required to have the same shape in consideration of compatibility with them. For this reason, although the tapes for wafer processing are diversified, since the shape of the adhesive layer is uniform, it is difficult to visually identify them.
For this reason, in recent years, in order to easily identify the type of wafer processing tape, a marking indicating the type of wafer processing tape has been applied to the upper surface of the adhesive layer or the adhesive layer. (For example, see Patent Documents 1 and 2).

JP 2006-269601 A JP 2007-288170 A

  By the way, in the bonding process to the semiconductor wafer by the wafer mounter as described above, when the release film is peeled off from the wafer processing tape subjected to such pre-cut processing, the tip of the wafer processing tape passes through the peeling wedge. In this case, there is a problem in that the tip portion of the adhesive layer is peeled off from the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape and a portion where the adhesive layer is not in close contact with the semiconductor wafer is formed.

This is because the peeling force (adhesive force) between the adhesive layer and the adhesive layer of the adhesive tape is very low.
However, increasing the peel force between the adhesive layer and the pressure-sensitive adhesive layer may cause a pickup error when the base film is expanded and the semiconductor chip is picked up in the subsequent process. I know that.
As a recent trend, in order to stack more semiconductor chips in one semiconductor package, it is increasingly progressing to reduce the thickness of the semiconductor chip, and in order to pick up such a thin semiconductor chip without mistakes. Is in a situation where a lower peeling force between the adhesive layer and the pressure-sensitive adhesive layer is required, and it is difficult to easily increase the peeling force.

  In addition, by using a radiation curable pressure-sensitive adhesive layer for the pressure-sensitive adhesive layer, in the bonding process to the wafer by the wafer mounter, the semiconductor adhesive sheet is peeled off from the protective film (separator) by the peeling wedge (peel plate). When the semiconductor element is picked up, the adhesive layer and the adhesive layer are kept at a high peel strength until bonding is performed on the wafer and the ring frame by the press roller. Although a method of reducing the peel strength between the pressure-sensitive adhesive layer and the adhesive layer by irradiating the adhesive layer with the semiconductor chip can be considered, as the semiconductor chip becomes thinner, the adhesive layer and the pressure-sensitive adhesive layer In the first place, it is difficult to increase the peel strength between the pressure-sensitive adhesive layer and the adhesive layer before radiation irradiation sufficiently, and the contact with the peel-off of the release film is difficult. It is difficult to prevent the peeling from the adhesive layer of the tip portion of the adhesive layer sufficiently.

  Accordingly, a main object of the present invention is to provide a wafer processing tape capable of preventing the adhesive layer from peeling off from the adhesive layer of the adhesive tape in the bonding step to the semiconductor wafer.

  In order to solve the above problems, according to one aspect of the present invention, a release film, an adhesive layer, a pressure-sensitive adhesive layer, and a base film are laminated in this order, and the pressure-sensitive adhesive includes the base film and the pressure-sensitive adhesive layer. In the tape for wafer processing in which the tape covers the adhesive layer and contacts the release film around the adhesive layer, from the base film side in the adhesive layer, the adhesive layer and the pressure-sensitive adhesive layer A marking is formed so as to cross over the boundary line, and a wafer processing tape is provided in which the adhesive layer and the adhesive layer are fused or welded by the marking.

  In the above wafer processing tape, the release film is formed in a strip shape, and when the release film is peeled from one end in the longitudinal direction, the marking is at least on the outer periphery of the adhesive layer. It is good also as a structure formed in the range including the peeling start point from.

  The marking on the wafer processing tape may be formed by laser irradiation, heating, or ultrasonic vibration.

According to the present invention, when the release film is peeled off, the marking is formed so as to straddle the boundary line between the adhesive layer and the pressure-sensitive adhesive layer, corresponding to the outer peripheral portion of the adhesive layer that is easily peeled off from the pressure-sensitive adhesive layer. Therefore, the adhesiveness of the adhesive layer with respect to the pressure-sensitive adhesive layer can be enhanced, and peeling of the adhesive layer can be effectively prevented. Further, in this case, the adhesion between the pressure-sensitive adhesive layer and the adhesive layer is enhanced only in the vicinity of the boundary line between the pressure-sensitive adhesive layer and the adhesive layer, which does not hinder the pickup of the semiconductor element after dicing.
In addition, since the marking indicating the information of the wafer processing tape is used, it is not necessary to increase the number of steps for taking measures for preventing the peeling of the adhesive layer when manufacturing the wafer processing tape. It becomes possible to enhance the peeling prevention effect of the adhesive layer while maintaining the productivity.

It is drawing which shows schematic structure of the tape for wafer processing. It is a longitudinal cross-sectional view which shows the schematic laminated structure of a peeling film, an adhesive bond layer, and an adhesive tape. It is drawing for demonstrating schematically the apparatus and method which paste the wafer processing tape on a semiconductor wafer and a ring frame. It is a figure which shows the formation area of the marking with respect to the boundary line of an adhesive bond layer and an adhesive layer. It is a figure which shows the formation area of the marking with respect to the boundary line of an adhesive bond layer and an adhesive layer. It is a figure which shows the formation area of the marking with respect to the boundary line of an adhesive bond layer and an adhesive layer. It is a figure which shows the formation area of the marking with respect to the boundary line of an adhesive bond layer and an adhesive layer. It is a figure which shows the formation area of the marking with respect to the boundary line of an adhesive bond layer and an adhesive layer. It is a figure which shows the formation area of the marking with respect to the boundary line of an adhesive bond layer and an adhesive layer. It is a figure which shows the formation position of the marking with respect to the boundary line of an adhesive bond layer and an adhesive layer. It is a figure which shows the formation position of the marking with respect to the boundary line of an adhesive bond layer and an adhesive layer. It is a figure which shows the formation position of the marking with respect to the boundary line of an adhesive bond layer and an adhesive layer.

[Tape for wafer processing]
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the wafer processing tape 1 is wound around a core 6 serving as a core material in a roll shape, and is drawn out from the core 6 during use.
As shown in FIG. 2, the wafer processing tape 1 mainly includes a strip-shaped release film 2, an adhesive layer 3, and an adhesive tape 4, and the adhesive tape 4 further includes an adhesive layer 41 and It is comprised from the base film 42. FIG. And the peeling film 2, the adhesive bond layer 3, the adhesive layer 41, and the base film 42 are laminated | stacked in this order.
The pressure-sensitive adhesive tape 4 is pre-cut in a circle so as to correspond to each wafer and the adhesive layer 3, and the adhesive layer 3 and the pre-cut pressure-sensitive adhesive tape 4 are along the longitudinal direction of the release film 2. Are formed side by side.

The adhesive layer 3 is formed in a circular shape having an outer diameter larger than that of the wafer corresponding to the shape of the wafer. In FIG. 1, the position where the wafer W is to be attached is shown by a two-dot chain line. As shown in the figure, the wafer W is stuck to the center of the adhesive layer 3 from which the release film 2 has been removed.
Further, the base film 42 and the pressure-sensitive adhesive layer 41 are formed in a circular shape having a larger outer diameter concentric with the adhesive layer 3 by precutting. As a result, as shown in FIG. 2, the pressure-sensitive adhesive tape 4 can also be adhered to the release film 2 on the surface of the pressure-sensitive adhesive layer 41 so as to surround the periphery of the adhesive layer 3.

  In addition, on the surface of the adhesive layer 3 and the pressure-sensitive adhesive layer 41 on the side of the release film 2, the boundary line between the adhesive layer 3 and the pressure-sensitive adhesive layer 41 (outer contour line of the adhesive layer 3) is straddled. A marking M indicating predetermined information regarding the wafer processing tape 1 is formed by heat treatment. For example, the marking M includes information provided for selecting a wafer processing tape suitable for use from various wafer processing tapes, such as the manufacturer, model number, material used, and size of the wafer processing tape 1. , Symbols, letters, designs, pictures, signs, etc.

For the formation of the marking M, laser irradiation, heat ray irradiation, ultrasonic welding, thermal printing, or other heating methods are used. At the forming position, the adhesive layer 3 and the pressure-sensitive adhesive layer 41 are fused or welded. Is heated to such an extent that The marking is formed from the side of the base film 42 in the adhesive layer 3, but when using a laser or heat rays, the base film 42 is transmitted and heated to produce ultrasonic or thermal printing. When using the adhesive layer 3, the adhesive layer 3 and the pressure-sensitive adhesive layer 41 are welded or fused via the base film 42.
In FIG. 2, a region where the marking M is formed by fusion or welding is illustrated by a two-dot chain line.
Further, “stretching the outer peripheral contour line” means that one end m1 of the marking M in the radial direction of the adhesive layer 3 is positioned inside the boundary line between the adhesive layer 3 and the adhesive layer 41 as shown in FIG. The other end m2 is located outside the boundary line between the adhesive layer 3 and the pressure-sensitive adhesive layer 41.
Further, the marking M may be formed over the entire circumference of the boundary line between the adhesive layer 3 and the pressure-sensitive adhesive layer 41, or may be a part thereof. As shown in FIG. 4, it is desirable to form the boundary line between the adhesive layer 3 and the pressure-sensitive adhesive layer 41 in a range including the peeling start point S in the direction A in which the peeling film 2 is unwound during the peeling operation.
Further, it is desirable to form the marking M outside the position where the wafer W is to be attached in the adhesive layer 3.

  Hereafter, each structure of the tape 1 for wafer processing, a manufacturing method, a usage method, etc. are demonstrated concretely.

[Peeling film]
As described above, the release film 2 is formed in a rectangular band shape, and plays a role as a carrier film during manufacture and use.
As the release film 2, a well-known film such as a polyethylene terephthalate (PET) system, a polyethylene system, or a film subjected to a release process can be used.

[Adhesive tape: Adhesive layer]
As shown in FIGS. 1 and 2, the pressure-sensitive adhesive tape 4 covers the adhesive layer 3 and can come into contact with the release film 2 around the adhesive layer 3.
In the adhesive tape 4, the adhesive layer 41 and the base film 42 formed on the entire surface of the release film 2 are pre-cut corresponding to the shape of the ring frame 5 for dicing (see FIG. 3), and the periphery of the circular region is It is formed by removing.

  The material used for the pressure-sensitive adhesive layer 41 is not particularly limited, but preferably contains a radiation polymerizable component. An acrylic copolymer (hereinafter referred to as “acrylic copolymer”) having at least a radiation-curable carbon-carbon double bond-containing group, a hydroxyl group and a group containing a carboxyl group with respect to the main chain, which is used for the pressure-sensitive adhesive layer 41. The compound (referred to as “union (A)”) may be produced by any method. For example, a copolymer (meth) acrylic acid ester, a hydroxyl group-containing unsaturated compound, a carboxyl group-containing unsaturated compound and the like ( The compound (A2) having a carbon-carbon double bond and a functional group capable of undergoing an addition reaction to the functional group of the copolymer (A1) having the carbon chain of A1) as the main chain can get.

As said (meth) acrylic acid ester, it is C6-C12 hexyl acrylate, n-octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, decyl acrylate, or a monomer having 5 or less carbon atoms. There can be listed pentyl acrylate, n-butyl acrylate, isobutyl acrylate, ethyl acrylate, methyl acrylate, or similar methacrylates. In this case, as the monomer having a larger carbon number is used as the monomer, the glass transition point becomes lower, so that the desired glass transition point can be produced.
In addition to the glass transition point, a low molecular compound having a carbon-carbon double bond such as vinyl acetate, styrene or acrylonitrile can be added within the range of 5% by mass or less for the purpose of improving compatibility and various performances. .

Examples of the hydroxyl group-containing unsaturated compound include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, and the like.
Examples of the carboxyl group-containing unsaturated compound include acrylic acid and methacrylic acid.

As the functional group of the compound (A2) having a functional group capable of addition reaction and a carbon-carbon double bond, the functional group of the copolymer (A1) is a carboxyl group or a cyclic acid anhydride group. In the case, a hydroxyl group, an epoxy group, an isocyanate group and the like can be mentioned. In the case of a hydroxyl group, a cyclic acid anhydride group, an isocyanate group and the like can be mentioned. Can be mentioned.
Specific examples of the compound (A2) include acrylic acid, methacrylic acid, cinnamic acid, itaconic acid, fumaric acid, phthalic acid, 2-hydroxyalkyl acrylates, 2-hydroxyalkyl methacrylates, glycol monoacrylates, glycol monoacrylate. Methacrylates, N-methylolacrylamide, N-methylolmethacrylamide, allyl alcohol, N-alkylaminoethyl acrylates, N-alkylaminoethyl methacrylates, acrylamides, methacrylamides, maleic anhydride, itaconic anhydride, fumaric anhydride Acid, phthalic anhydride, glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, polyisocyanate compounds with hydroxyl group or carboxyl group and photopolymerizability Containing - can enumerate such as those urethanization a monomer having a carbon-carbon double bond.

In the synthesis of the acrylic copolymer (A), as the organic solvent when the copolymerization is performed by solution polymerization, a ketone, ester, alcohol, or aromatic solvent can be used. Among them, generally good solvents for acrylic polymers, such as toluene, ethyl acetate, isopropyl alcohol, benzene methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone and the like, solvents having a boiling point of 60 to 120 ° C. are preferable, and polymerization initiators include α, α A radical generator such as an azobis type such as' -azobisisobutylnitrile or an organic peroxide type such as benzoberperoxide is usually used. At this time, if necessary, a catalyst and a polymerization inhibitor can be used in combination. The polymerization temperature and the polymerization time are adjusted, and then an addition reaction at a functional group is performed, whereby an acrylic copolymer (A ) Can be obtained.
In terms of adjusting the molecular weight, it is preferable to use a mercaptan or carbon tetrachloride solvent. The copolymerization is not limited to solution polymerization, and other methods such as bulk polymerization and suspension polymerization may be used.

As described above, the acrylic copolymer (A) can be obtained. The weight average molecular weight of the acrylic copolymer (A) is preferably about 300,000 to 1,000,000. If it is less than 300,000, the cohesive force of radiation irradiation becomes small, and when the wafer is diced, the element is likely to be displaced, and image recognition may be difficult. Further, in order to prevent this element displacement as much as possible, the molecular weight is preferably 400,000 or more. This is because if the molecular weight exceeds 1,000,000, gelation may occur during synthesis and coating.
In terms of characteristics, the glass transition point is low, so even if the molecular weight is large, when the whole is irradiated with radiation instead of a pattern, the fluidity of the adhesive after irradiation is not sufficient, so the element gap after stretching Is not sufficient, and there is no problem that image recognition at the time of pick-up is difficult, but it is still preferable that it is 900,000 or less. In addition, the molecular weight in this invention is a weight average molecular weight of polystyrene conversion.

  In addition, in the pressure-sensitive adhesive layer 41, the amount of the photopolymerizable carbon-carbon double bond introduced into the acrylic copolymer (A) may be an amount that provides a sufficient adhesive force reduction effect after radiation curing. Although it varies depending on the use conditions such as the UV irradiation amount and is not unambiguous, it is preferably 0.5 to 2.0 meq / g, more preferably 0.8 to 1.5 meq / g. If the amount of double bonds is too small, the effect of reducing the adhesive strength after irradiation is reduced. If the amount of double bonds is too large, the fluidity of the adhesive after irradiation is not sufficient, and the gap between the elements after stretching. Is insufficient, and image recognition of each element may be difficult at the time of pickup. Furthermore, the acrylic copolymer (A) itself lacks stability, making it difficult to produce.

  Furthermore, the acrylic copolymer (A) has a group containing an unreacted hydroxyl group and a carboxyl group with respect to the main chain. It is preferable that the acrylic copolymer (A) has a hydroxyl group having a hydroxyl value of 5 to 100 because the risk of pick-up mistakes can be further reduced by reducing the adhesive strength after radiation irradiation. The hydroxyl value is more preferably 20 to 70. In addition, when the acrylic copolymer (A) has a carboxyl group having an acid value of 0.5 to 30, by improving the tape recoverability, it is easy to cope with a used tape storage type mechanism. This is preferable. The acid value is more preferably 1 to 10. Here, if the hydroxyl value of the acrylic copolymer (A) is too low, the effect of reducing the adhesive strength after irradiation is not sufficient, and if it is too high, the fluidity of the adhesive after irradiation is impaired. On the other hand, if the acid value is too low, the effect of improving the tape restoring property is not sufficient, and if it is too high, the fluidity of the pressure-sensitive adhesive is impaired.

When the radiation curable pressure-sensitive adhesive layer 41 used for the wafer processing tape 1 is cured by ultraviolet irradiation, 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-hydroxymethylphenylpropane, and 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 polymer.
Furthermore, the radiation curable pressure-sensitive adhesive layer can contain, for example, a curing agent such as a polyisocyanate compound as a subcomponent as necessary. As for the compounding quantity of a hardening | curing agent, 0.5-10 mass parts is preferable with respect to 100 mass parts of acrylic polymers which are a main component.
The thickness of the pressure-sensitive adhesive layer 41 is preferably 5 to 50 [μm].

[Adhesive tape: Base film]
The base film 42 of the pressure-sensitive adhesive tape 4 may be a known film as long as it has radiolucency as the film. For example, polyethylene, polypropylene, ethylene-propylene copolymer, polybutene, ethylene-vinyl acetate. Copolymer, ethylene-acrylic acid ester copolymer, homopolymer or copolymer of α-olefin such as ionomer, engineering plastic such as polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polyurethane, styrene-ethylene-butene Or thermoplastic elastomers, such as a pentene-type copolymer, are mentioned. Alternatively, a mixture of two or more selected from these groups or a multilayered structure may be used.
The thickness of the base film 42 is preferably 50 to 200 [μm].
Moreover, the base film 42 may be a mixture of two or more materials selected from these groups, or may be a single layer or a multilayer.

[Adhesive layer]
The material used for the adhesive layer 3 of the wafer processing tape 1 is not particularly limited, and known polyimide resins, polyamide resins, polyetherimide resins, polyamideimide resins, polyester resins, used for adhesives, Polyesterimide resin, phenoxy resin, polysulfone resin, polyethersulfone resin, polyphenylene sulfide resin, polyether ketone resin, chlorinated polypropylene resin, acrylic resin, polyurethane resin, epoxy resin, silicon oligomer, and the like can be used.

[How to use wafer processing tape]
The operation of attaching the wafer processing tape 1 to the semiconductor wafer W and the ring frame 5 will be described with reference to FIG.
At the time of this affixing operation, the wafer processing tape 1 is unwound from the roll body, conveyed along a predetermined path, and only the release film 2 is mainly taken up by the roller 100.
A peeling wedge 101 is provided in the conveyance path of the wafer processing tape 1, and the peeling film 2 is folded using the tip of the peeling wedge 101 as a folding point. At this time, since the marking M is heated and formed so as to straddle the end portion (peeling origin S) on the downstream side in the conveyance direction at the boundary line between the adhesive layer 3 and the pressure-sensitive adhesive layer 41, Adhesiveness with the adhesive tape 4 is enhanced at the peeling start point S of the adhesive layer 3, and even if the adhesive layer 3 is pulled by the folded release film 2, the adhesive layer 3 is prevented from peeling from the adhesive tape 4.
Accordingly, only the release film 2 is taken up by the take-up roller 100 at the tip of the release wedge 101.

A suction stage 102 is provided on the extension line in the transport direction of the tip of the peeling wedge 101, and the semiconductor wafer W and the ring frame 5 are installed on the top surface of the suction stage 102.
The adhesive layer 3 and the adhesive tape 4 from which the release film 2 has been peeled off by the peeling wedge 101 are guided onto the semiconductor wafer W and bonded to the wafer W by the bonding roller 103.

Thereafter, the semiconductor wafer W is diced with the adhesive layer 3 attached to the semiconductor wafer W and the adhesive tape 4 attached to the ring frame 5.
Next, the adhesive tape 4 is subjected to a curing process such as radiation irradiation to pick up a semiconductor wafer W (semiconductor chip) after dicing. At this time, since the peeling force of the pressure-sensitive adhesive tape 4 is reduced by the curing process, the adhesive layer 3 is easily peeled off from the pressure-sensitive adhesive layer 12 of the pressure-sensitive adhesive tape 4, and the adhesive layer 3 is adhered to the back surface of the semiconductor chip. Picked up in state. Further, since the marking M is out of the bonding position of the semiconductor wafer W with respect to the adhesive layer 3, there is no influence on the pickup.
The adhesive layer 3 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.

[Technical effects in wafer processing tape]
In the wafer processing tape 1, the boundary line R between the adhesive layer 3 and the pressure-sensitive adhesive layer 41 corresponds to the outer peripheral portion of the adhesive layer 3 that easily peels from the pressure-sensitive adhesive layer 41 when the release film 2 is peeled off. Since the marking M is formed by heating on the surface of the adhesive layer 3 so as to straddle the adhesive layer 3, the adhesion of the adhesive layer 3 to the pressure-sensitive adhesive layer 41 can be improved, and the peeling of the adhesive layer 3 is effective. Can be prevented. Further, since the marking M is formed only around the boundary line R, and further, the position where the wafer is scheduled to be bonded is avoided, so that the pick-up of the semiconductor element after dicing is not hindered.
Further, since the marking M indicating the information of the wafer processing tape 1 is used, it is not necessary to increase the number of steps for taking measures for preventing the adhesive layer 3 from being peeled off when the wafer processing tape 1 is manufactured. Therefore, it is possible to enhance the peeling prevention effect of the adhesive layer 3 while maintaining the conventional productivity.
The marking M can be easily formed by using a known method such as laser heating, heat ray irradiation, ultrasonic welding, thermal printing, or the like.
In addition, since the adhesive layer 3 and the pressure-sensitive adhesive layer 41 are formed with heat fusion or welding, the marking M can obtain a more reliable peeling prevention effect.

Hereinafter, the peeling prevention effect of the adhesive layer is compared with a plurality of examples and comparative examples formed by changing various conditions such as the marking forming range, forming position, presence / absence of forming, and forming method of the wafer processing tape. The comparative test will be described.
The pressure-sensitive adhesive layer (X) of the wafer processing tape may be produced in any way, but here, an acrylic polymer having a radiation-polymerizable carbon-carbon double bond (molecular weight 700,000 Mw, Tg = −65 ° C) 100 parts, polyisocyanate curing agent 6 parts, 1 part of photopolymerization initiator (2,2-dimethoxy-2-phenylacetophenone) is blended, polyolefin base film (Z) (thickness 100 [μm ]) And then dried at 110 ° C. for 2 minutes to prepare an adhesive layer (X) and a base film (Z) portion of the wafer processing tape.

For the adhesive layer, 100 parts of an acrylic copolymer, 100 parts of a cresol novolac type epoxy resin, 10 parts of a xylene novolac type phenol resin, 5 parts of 2-phenylimidazole and 0.5 part of xylenediamine as an epoxy curing agent are blended. Then, an adhesive layer (a) obtained by applying it to a PET film and drying it at 110 ° C. for 2 minutes so that the thickness of the adhesive layer was 10 [μm] was used.
Furthermore, the adhesive film produced as described above is subjected to precut processing in a predetermined size and shape, and is bonded to a thickness of 10 [μm] punched out in a shape larger than the wafer size prepared as described above. What bonded the agent layer (a) on this adhesive layer (X) was made into the tape for wafer processing.

Next, from the surface of the base film (Z) of the tape for wafer processing, it is optional by laser irradiation or thermal printing only in the range of FIG. 4 to FIG. 9 except for the wafer bonding planned portion in the adhesive layer (a). Marking of the design was performed. 4 to 9, the upper part shows the downstream side in the transport direction in the attaching operation to the semiconductor wafer and the ring frame. That is, the upper end portion of the boundary line R between the adhesive layer (a) and the pressure-sensitive adhesive layer in the figure serves as a peeling start point.
In the example of FIG. 4, marking is performed so as to straddle the boundary line R over the entire circumference of the boundary line R (referred to as pattern A), and in the example of FIG. Marking is performed so as to straddle the boundary line R at two locations, the end and the upstream end (referred to as pattern B), and in the example of FIG. In FIG. 7, no marking is given to any of the boundary lines R (assuming that there is no pattern). In the example of FIG. 8, marking is performed so as to cross the boundary line R in a range excluding the downstream end and the upstream end of the boundary line R (referred to as pattern D). In the example, the boundary line R is crossed in the range excluding only the downstream end of the boundary line R in the transport direction. Uni marking has been applied (a pattern E).

  In addition, in order to perform comparison in the case where the marking formation position with respect to the boundary line R is different, in the example of FIG. 10, marking is performed at a position across the boundary line R (referred to as pattern i), and in the example of FIG. Marking was performed on the inner side of the boundary line R (referred to as pattern ii), and in the example of FIG. 12, marking was performed on the outer side of the boundary line R (referred to as pattern iii).

The laser irradiated by laser irradiation may be any laser type and wavelength that are generally used for forming a laser mark. In this example and a comparative example, using a CO2 laser marker, the region of FIGS. 4 to 9 except for the wafer bonding planned portion in the adhesive layer on the surface of the adhesive layer (a) of the wafer processing tape, and Marking was formed by irradiating the position of FIGS.
For thermal printing, any method that is generally used may be used. In this example and the comparative example, the wafer bonding schedule on the adhesive layer is made on the surface of the adhesive layer of the wafer processing tape. Thermal printing was performed in the areas of FIGS. 4 to 9 and the positions of FIGS.
In addition, ultrasonic welding or fusion may be performed by any generally used method. In this example and the comparative example, an ultrasonic marking device is used, and an adhesive layer of a wafer processing tape ( On the surface of a), ultrasonic processing was performed on the region of FIGS. 4 to 9 and FIGS. 10 to 12 except for the wafer bonding planned portion of the adhesive layer (a).
The shape of the mark applied by laser irradiation, thermal printing, ultrasonic welding, or the like may be any symbol, code, character, design, sign, etc. that crosses the outer contour R.

  These wafer processing tapes were provided with a polyethylene terephthalate (PET) release film on the surface of the adhesive layer opposite to the adhesive layer.

  The application conditions of Examples 1-9 are shown in Table 1, and the application conditions of Comparative Examples 1-18 are shown in Table 2. The wafer processing tape produced according to the application conditions of Examples 1 to 9 and Comparative Examples 1 to 18 was set in the wafer bonding apparatus shown in FIG. 3, and the bonding property at a bonding temperature of 70 ° C. was confirmed. . The ones that could be pasted without any problem at the time of pasting were rated as “◯”, and the one that the adhesive layer and the adhesive film were peeled off and the adhesive layer was turned up was marked as “X”.

As a result of the comparative test, as shown in Table 1, in Examples 1 to 9, the result is good in the bonding test, and is the outer peripheral portion of the adhesive layer (a) and including the peeling start point S with the peeling film. It was found that the adhesive layer (a) can be prevented from peeling off from the pressure-sensitive adhesive layer (X) of the pressure-sensitive adhesive tape if the adhesive force is increased more than the planned bonding part of the semiconductor wafer. Further, it was found that the marking can be prevented from peeling off the adhesive layer (a) when formed by any of laser heating, thermal printing, and ultrasonic heating. In addition, since the marking is removed from the planned bonding part of the semiconductor wafer, a pickup mistake is not attracted.
In each of Comparative Examples 1 to 19, the adhesive film and the adhesive layer were peeled off, and the adhesive layer was turned up.

DESCRIPTION OF SYMBOLS 1 Wafer processing tape 2 Release film 3 Adhesive layer 4 Adhesive tape 41 Adhesive layer 42 Base film M Marking R Boundary line

Claims (5)

A release film, an adhesive layer, a pressure-sensitive adhesive layer, and a base film are laminated in this order,
In the tape for wafer processing that the adhesive tape comprising the base film and the adhesive layer covers the adhesive layer, and is in contact with the release film around the adhesive layer,
From the base film side in the adhesive layer, marking is formed so as to straddle the boundary line between the adhesive layer and the pressure-sensitive adhesive layer,
A wafer processing tape, wherein the pressure-sensitive adhesive layer and the adhesive layer are fused or welded by the marking. In the case where the release film is formed in a strip shape and the release film is peeled from one end in the longitudinal direction,
2. The wafer processing tape according to claim 1, wherein the marking is formed in a range including at least a peeling starting point from the peeling film on an outer periphery of the adhesive layer.   3. The wafer processing tape according to claim 1, wherein the marking is formed by laser irradiation.   3. The wafer processing tape according to claim 1, wherein the marking is formed by heating.   3. The wafer processing tape according to claim 1, wherein the marking is formed by ultrasonic vibration.

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