TWI387997B - Wafer processing tape - Google Patents

Description

Wafer processing tape

The present invention relates to a tape for wafer processing.

In the manufacturing step of the semiconductor device, the steps of: dicing the germanium wafer into a wafer unit, picking up the cut semiconductor device (wafer), and then bonding (mounting) the picked wafer to the wire Steps such as frame or package substrate. In the wafer processing belt used in the manufacturing process of the above-described semiconductor device, a dicing adhesive wafer in which an adhesive layer and an adhesive layer are sequentially formed on a support substrate has been known (for example, see Patent Document 1).

In the wafer processing belt in which the adhesive layer and the adhesive layer are sequentially formed on the substrate, the time during which the adhesive layer contacts the adhesive layer is inevitable during the period from manufacture to use, so that it is used. The front adhesive layer and the adhesive layer are fused, and in the step of picking up the singulated semiconductor element with the adhesive layer, there is a problem that the adhesive layer and the adhesive layer cannot be smoothly peeled off.

Therefore, in the wafer processing belt which solves such a problem, it is known that a semiconductor element which is singulated with an adhesive layer can be easily formed by providing a peeling layer between the adhesive layer and the adhesive layer. The self-adhesive layer is peeled off (for example, refer to Patent Document 2). Further, there is known a wafer processing belt which is excellent in adhesion to an adherend layer by controlling the surface free energy of the adhesive layer before curing, and which is excellent in adhesion to the adhesive layer. Patent Document 3).

[Patent Document 1] Japanese Laid-Open Patent Publication No. 60-57642

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2005-277383

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2008-244463

Such a wafer processing tape is used in the steps shown below.

(1) a step of sequentially laminating a supporting substrate, an adhesive layer, and an adhesive layer to form a wafer processing tape,

(2) a step of bonding the adhesive layer of the wafer processing tape to the back surface of the germanium wafer,

(3) a step of attaching a wafer ring to an adhesive layer formed on a support substrate of a wafer processing tape,

(4) a cutting step of cutting the above-mentioned tantalum wafer into a semiconductor element (wafer),

(5) a picking step of peeling and taking out the semiconductor element with the adhesive layer from the adhesive layer, and

(6) A die bonding step of bonding the semiconductor element to an external connection wiring member or other semiconductor element to which a wiring such as a lead frame is attached.

Therefore, the surface of the adhesive layer which is in contact with the object to be bonded by the die bonding step becomes the surface which is peeled off once after bonding to the adhesive layer, and the surface free energy thereof changes, so that there is a problem that even if the control is separate When the adhesive layer is used, the surface free energy sometimes does not exhibit sufficient adhesion.

Accordingly, an object of the present invention is to provide a wafer processing belt having an adhesive layer having sufficient adhesion even if it is bonded to the surface of the adhesive layer once after being bonded to the adhesive layer.

The above problems are solved by the following means.

(1) A tape for processing a wafer, comprising: a support substrate, an adhesive layer, and a single layer of an adhesive layer, wherein the adhesive layer is used to crimp a semiconductor element to the outside of the wiring; In the connection wiring member or another semiconductor element, the difference in surface free energy between the surface on which the adhesive layer is peeled off from the adhesive layer and the surface not in contact with the adhesive layer is 10 mJ/m ² or less.

(2) The wafer processing belt according to (1), wherein a surface free energy of a surface of the adhesive layer not in contact with the adhesive layer is 30 mJ/m ² or more and 50 mJ/m ² or less.

(3) The wafer processing belt according to (1) or (2), wherein the adhesive layer contains a polymer compound produced by suspension polymerization of acrylonitrile.

In the present invention, the term "adhesive" refers to a resin composition for fixing a semiconductor element (wafer) to a wiring member or other semiconductor element in a die bonding step of manufacturing a semiconductor device, and the so-called adhesive is It is disposed on a support substrate and is bonded to the back surface of the germanium wafer through an adhesive layer in a cutting step of manufacturing a semiconductor device, and is used for temporarily fixing the germanium wafer with an adhesive by the adhesive force thereof. A resin composition in a ring frame.

According to the present invention, it is possible to provide a wafer processing belt which has an adhesive layer which has sufficient adhesion even if it is peeled off once after being bonded to the pressure-sensitive adhesive layer.

The above and other features and advantages of the present invention will become more apparent from the description of the appended claims.

The wafer processing belt of the present invention sequentially laminates a support substrate, an adhesive layer, and a single layer of an adhesive layer. Fig. 1 is a cross-sectional view schematically showing a wafer processing belt of the present invention. The wafer processing tape 10 is composed of an adhesive film 12 and an adhesive layer 13. The adhesive film 12 is formed by laminating an adhesive layer 12b on the support substrate 12a. The release PET film 11 is laminated on the adhesive layer 13, and is peeled off at the time of use, and the tantalum wafer is used next to the adhesive layer 13.

(surface free energy)

In the present invention, the surface free energy system is a value obtained by measuring the contact angle between water and diiodomethane (droplet capacity: water 2 μL, diiodomethane 3 μL, reading time: 30 seconds after dropping) and calculating according to the following formula.

γ _s : surface free energy

: Polar component of surface free energy

: Dispersed components of surface free energy

θ ^H : contact angle of water relative to the solid surface

θ ^I : contact angle of methylene diiodide relative to solid surface

Although it is not clear that by controlling the difference in surface free energy, it is possible to manufacture a wafer processing tape having an adhesive layer having a sufficient adhesion even if it is bonded to the adhesive layer once after being bonded to the adhesive layer. Speculated as follows.

By controlling the difference in surface free energy, it is possible to suppress the case where only one of the adhesions becomes extremely low, and to maintain the failure mode of the adhesive as a cohesive failure. In the case where the failure mode of the adhesive is agglomeration failure, as long as the adhesive itself has no problem, the fixing of the semiconductor element is not problematic, and resistance is generated even if thermal stress is generated in the reflow step. However, if the control is insufficient and only one of the adhesions becomes extremely low, the failure mode of the adhesive will become an interface failure, and even if the strength of the adhesive is sufficient, the peeling will continue due to thermal stress, resulting in peeling. Reliability (resistance to crack resistance during reflow) decreases.

In the wafer processing belt of the present invention, the difference in surface free energy between the surface on which the adhesive layer is peeled off from the adhesive layer and the surface not in contact with the adhesive layer is 10 mJ/m ² or less, preferably 0.1 to 5.0 mJ/ m ² . In the case where the difference in surface free energy exceeds 10 mJ/m ² , there is a possibility that the component is transferred from the adhesive layer to the adhesive layer or from the adhesive layer to the adhesive layer. In the former case, the low molecular components in the reflow step are volatilized. In the latter case, the adhesion surface is roughened, and the unevenness is not filled in the bonding step, resulting in voids, resulting in a decrease in reliability (resistance to cracking during reflow).

The surface free energy of the surface of the adhesive layer which is not in contact with the adhesive layer is preferably 30 mJ/m ² or more and 50 mJ/m ² or less, and the surface free energy of the surface of the adhesive layer peeled off from the adhesive layer is preferably 30 mJ/m. ² or more and 60 mJ/m ² or less. The surface free energy of the surface where the layer of the adhesive layer is not in contact with the adhesive layer is more preferably 30 mJ/m ² or more and 40 mJ/m ² or less, and the surface free energy of the surface of the adhesive layer peeled off from the adhesive layer is more preferably 30 mJ/m. ² or more and 50 mJ/m ² or less. If the surface free energy is less than 30 mJ/m ² , the wettability may be insufficient, and thus voids may be easily formed, resulting in a decrease in reliability (resistance to cracking during reflow).

(adhesive layer)

The subsequent layer is formed by forming a film of an adhesive in advance, and for example, a known polyimine resin, a polyamide resin, a polyether quinone resin, a polyamidimide resin, or the like, which is used for an adhesive, can be used. Polyester resin, polyester phthalimide resin, phenoxy resin, polyfluorene resin, polyether oxime resin, polyphenylene sulfide resin, polyether ketone resin, chlorinated polypropylene resin, acrylic resin, polyurethane resin Epoxy resin, polypropylene decylamine resin, melamine resin, or the like, or a mixture thereof, preferably contains an acrylic copolymer, an epoxy resin, and an acrylic resin from the viewpoint of adhesion and reliability of the adhesive layer. The copolymer has a Tg of from 0 ° C to 40 ° C and a mass average molecular weight of from 100,000 to 1,000,000. A more preferable mass average molecular weight is 600,000 or more and 900,000 or less.

Further, the mass average molecular weight was measured by a gel permeation chromatography (GPC) method using a calibration curve of standard polystyrene.

(Measurement conditions of GPC method)

Machine: High Performance Liquid Chromatograph LC-20AD [Made in Shimadzu Corporation, trade name]

Pipe column: Shodex Column GPC KF-805 [manufactured by Shimadzu Corporation, trade name]

Lysate: chloroform

Measuring temperature: 45 ° C

Flow rate: 3.0ml/min

RI detector: RID-10A

The polymerization method of the acrylic copolymer is not particularly limited, and examples thereof include bead polymerization, solution polymerization, suspension polymerization, and the like, and a copolymer can be obtained by these methods. The suspension polymerization is preferably excellent in heat resistance, and examples of such an acrylic copolymer include Paracron W-197C (manufactured by Kokusai Kogyo Co., Ltd., trade name).

The acrylic copolymer preferably contains acrylonitrile. The acrylonitrile is preferably 10 to 50% by mass, and more preferably 20 to 40% by mass based on the acrylic copolymer. When the acrylonitrile is 10% by mass or more, the Tg of the adhesive layer can be improved, and the adhesion can be improved. However, when the content is 50% by mass or more, the fluidity of the adhesive layer is deteriorated, and the adhesiveness is lowered. Particularly preferred is an acrylic copolymer produced by suspension polymerization of acrylonitrile.

The acrylic copolymer may have a functional group in order to improve adhesion. The functional group is not particularly limited, and examples thereof include an amine group, an urethane group, a quinone group, a hydroxyl group, a carboxyl group, and a glycidyl group. Among them, a glycidyl group is preferred. The epoxy propylene has good reactivity with an epoxy resin as a thermosetting resin, and is less likely to react with the adhesive layer than a hydroxyl group or the like, so that it is less likely to cause a change in surface free energy.

The subsequent layer may contain an inorganic filler. However, if the amount of addition is high, the fluidity is lowered and the adhesion is lowered. Therefore, it is preferably less than 40% by mass, more preferably less than 20% by mass, and even more preferably less than 15% by mass. Further, when the particle diameter is large, irregularities are formed on the surface of the adhesion surface, and the adhesion is lowered. Therefore, the average particle diameter is preferably less than 1 μm, more preferably less than 0.5 μm, still more preferably less than 0.1 μm. The lower limit of the particle diameter of the inorganic filler is not particularly limited, but is actually 0.003 μm or more.

In order to control the surface free energy, a decane coupling agent or a titanium coupling agent or a fluorine-based graft copolymer may be added as an additive. These additives are preferably those containing a mercapto group or an epoxy group.

The thickness of the subsequent agent layer is not particularly limited, and is usually preferably from 3 to 100 μm, more preferably from 5 to 20 μm.

(support substrate)

Examples of the material for supporting the substrate include polyethylene, polypropylene, ethylene-propylene copolymer, polybutene-1, poly-4-methylpentene-1, ethylene-vinyl acetate copolymer, and ethylene-acrylic acid B. a homopolymer or copolymer of an α-olefin such as an ester copolymer, an ethylene-methyl acrylate copolymer, an ethylene-acrylic acid copolymer, an ionic polymer, or a mixture thereof, a polyurethane, a styrene-ethylene-butene copolymer or A thermoplastic elastomer such as a pentene copolymer or a polyamine-polyol copolymer and a mixture thereof. Further, it may be a mixture of two or more materials selected from the group, or may be a single layer or a plurality of layers. The thickness of the support substrate is not particularly limited, and can be appropriately set, and is preferably 50 to 200 μm.

(adhesive layer)

The adhesive layer has a radiation hardening type in which the radiation hardening type and the adhesive force are not changed by radiation irradiation. The former is easy to control the adhesion, and the latter can be used for a device that does not allow radiation to be irradiated, so that it can be appropriately selected depending on the use. In the case of selecting a radiation hardening type, it is preferably prepared by blending a radiation polymerizable compound having a photopolymerizable carbon-carbon double bond or a photopolymerization initiator.

In the case where the adhesive layer is of a radiation hardening type, it is preferred to use a peeling force of the adhesive layer and the adhesive layer after curing to be 0.01 N/25 mm or more and 0.5 N/25 mm or less. More preferably, it is 0.01 N/25 mm or more and 0.1 N/25 mm or less. When the peeling force is less than 0.01 N/25 mm, there is a possibility that the semiconductor element with the adhesive layer is detached from the adhesive layer when the self-cutting device is transported to the pick-up device, and if it exceeds 0.5 N/25 mm, the adhesive layer becomes It is easily affected by the adhesive layer, the surface is rough, or the surface component is transferred, resulting in easy change of surface free energy.

In the case where the adhesive layer is of a non-radiation-hardening type, it is preferred to use a peeling force of the adhesive layer and the adhesive layer of 0.01 N/25 mm or more and 0.5 N/25 mm or less. More preferably, it is 0.01 N/25 mm or more and 0.3 N/25 mm or less. If the peeling force is less than 0.01 N/25 mm, there is a possibility that the semiconductor element with the adhesive layer is detached from the adhesive layer when the wafer is flying at the time of cutting or when the self-cutting device is transported to the pick-up device, if it exceeds 0.5 N/ At 25 mm, the adhesive layer becomes susceptible to the influence of the adhesive layer, the surface is rough, or the surface component is transferred, resulting in a change in surface free energy.

The thickness of the adhesive layer is not particularly limited, but is usually preferably 5 to 50 μm, more preferably 7 to 20 μm.

[Examples]

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

<Manufacture of acrylic polymer>

First, a method for producing an acrylic polymer contained in an adhesive layer of a wafer processing belt of each of the examples and the comparative examples will be described.

(acrylic polymer (1))

300 parts by weight of water was added to a four-neck round bottom flask made of a glass equipped with a stirrer, and 0.7 parts by mass of polyvinyl alcohol was dissolved as a dispersion stabilizer, and the mixture was stirred at 300 rpm by a stirring blade, and the mass of ethyl acrylate 60 was simultaneously added. a monomer mixture of 5 parts by mass of butyl acrylate, 15 parts by mass of glycidyl methacrylate, 20 parts by mass of acrylonitrile, and N,N'-azobisisobutyronitrile as a polymerization initiator 1 part by mass, and a suspension was prepared.

The temperature inside the reaction system was raised to 68 ° C with continued stirring, and fixed for 4 hours to cause a reaction. Thereafter, it was cooled to room temperature (about 25 ° C). Then, the reactant was subjected to solid-liquid separation, and sufficiently washed with water, and then dried at 70 ° C for 12 hours using a dryer, followed by addition of 2-butanone and adjustment of the solid content to 15% to obtain acrylic acid polymerization. (1). The Tg calculated from the blend ratio was 3 °C. The polymer had a mass average molecular weight of 950,000 and a degree of dispersion of 3.5 as measured by Gel Permeation Chromatography (GPC).

(acrylic polymer (2))

It is produced by the same manufacturing method as the acrylic polymer (1) except that it is 60 parts by mass of ethyl acrylate, 5 parts by mass of butyl acrylate, 6 parts by mass of glycidyl methacrylate, and 29 parts by mass of acrylonitrile. Acrylic polymer (2). The Tg calculated from the blend ratio was 7 °C. The polymer had a mass average molecular weight of 600,000 and a degree of dispersion of 3.4 as measured by gel permeation chromatography.

(acrylic polymer (3))

It is produced by the same manufacturing method as the acrylic polymer (1) except that it is 34 parts by mass of ethyl acrylate, 15 parts by mass of butyl acrylate, 2 parts by mass of glycidyl methacrylate, and 49 parts by mass of acrylonitrile. Acrylic polymer (3). The Tg calculated from the blend ratio was 21 °C. The polymer had a mass average molecular weight of 120,000 and a degree of dispersion of 2.3 by gel permeation chromatography.

(acrylic polymer (4))

It is produced by the same manufacturing method as the acrylic polymer (1) except that it is 43 parts by mass of ethyl acrylate, 15 parts by mass of butyl acrylate, 5 parts by mass of glycidyl methacrylate, and 37 parts by mass of acrylonitrile. Acrylic polymer (4). The Tg calculated from the blend ratio was 12 °C. The polymer had a mass average molecular weight of 700,000 and a degree of dispersion of 3.6 as measured by gel permeation chromatography.

(acrylic polymer (5))

It is produced by the same manufacturing method as the acrylic polymer (1) except that it is 65 parts by mass of ethyl acrylate, 23 parts by mass of butyl acrylate, 2 parts by mass of glycidyl methacrylate, and 10 parts by mass of acrylonitrile. Acrylic polymer (5). The Tg calculated from the blend ratio was -22 °C. The polymer had a mass average molecular weight of 400,000 and a dispersion of 3.8 as measured by gel permeation chromatography.

(acrylic polymer (6))

60 parts by mass of ethyl acrylate, 5 parts by mass of butyl acrylate, 16 parts by mass of glycidyl methacrylate, and 19 parts by mass of acrylonitrile were added to a reactor equipped with a mixer and a cooler, and heated to 85 ° C. After adding 2 parts by mass of 2-butanone and 0.05 parts by mass of tert-butyl peroxybenzoate, the mixture was kept for 8 hours, and after cooling, methanol was added to precipitate the polymer, and the supernatant was removed, and the methanol remaining in the polymer was dried. Next, 2-butanone was added and the solid content was adjusted to 15% to prepare an acrylic polymer (6). The Tg calculated from the blend ratio was 3 °C. The polymer had a mass average molecular weight of 500,000 as measured by gel permeation chromatography and a degree of dispersion of 11.5.

Further, the mass average molecular weight of each of the acrylic polymers (1) to (6) was measured by a gel permeation chromatography (GPC) method using a calibration curve of standard polystyrene.

<Manufacture of adhesive layer>

(adhesive layer (1))

25 parts by mass of a cresol novolak type epoxy resin (epoxy equivalent 197, molecular weight 1200, softening point 70 ° C) and a xylenol varnish resin (hydroxyl group equivalent 104) were added to 100 parts by mass of the acrylic polymer (1). 60 parts by mass of softening point: 80 parts by mass, 20 parts by mass of a cerium oxide filler having an average particle diameter of 0.045 μm as a filler, and a thermosetting adhesive composition was obtained. The adhesive composition was applied to a PET film forming a release film at 120. C was dried by heating for 10 minutes to form a coating film of a B-stage state having a thickness of 20 μm after drying, and a laminate of a PET film/adhesive layer (1)/PET film was obtained.

Further, as the PET film, a PET film treated by a polyfluorene ion treatment (People: Purex S-314 (trade name), thickness: 25 μm) was used.

(adhesive layer (2) to (6))

The adhesive layers (2) to (6) were respectively obtained by the same method as the adhesive layer (1) except that any one of the acrylic polymers (2) to (6) was used instead of the above acrylic polymer (1). .

<Manufacture of Adhesive Film>

(adhesive layer composition (1))

77 parts by mass of 2-ethylhexyl acrylate and 23 parts by mass of 2-hydroxypropyl acrylate were polymerized, and 3 parts by mass of a polyisocyanate as a curing agent was added to an acrylic copolymer having a mass average molecular weight of 800,000 and mixed. Adhesive layer composition (1).

(adhesive layer composition (2))

A mass average molecular weight of 65 parts by mass of butyl acrylate, 25 parts by mass of 2-hydroxyethyl acrylate, and 10 parts by mass of acrylic acid, and dropwise addition of 2-isocyanatoethyl methacrylate and reaction thereof To the acrylic copolymer of 800,000, 3 parts by mass of a polyisocyanate as a curing agent and 1 part by mass of 1-hydroxycyclohexyl-phenyl ketone as a photopolymerization initiator were mixed and mixed to prepare an adhesive layer composition (2). ).

(adhesive film (1), (2))

Any of the produced adhesive layer compositions was applied to a PET film forming a release film so that the dried film thickness became 10 μm, and dried at 120 ° C for 3 minutes. By transferring the adhesive layer composition applied to the PET film to a polypropylene-hydrogenated Styrene-Butadiene Rubber elastomer having a thickness of 100 μm as a supporting substrate (PP: On the resin film of HSBR=80:20), adhesive films (1) and (2) were produced, respectively.

Further, polypropylene (PP) was made using Novatec FG4 (trade name) manufactured by Japan Polychem Co., Ltd., and hydrogenated styrene butadiene rubber (HSBR) was made using Dynaron 1320P (trade name) manufactured by JSR Corporation. Further, as the PET film, a PET film treated by polyfluorene ionization (People: Purex S-314 (trade name), thickness: 25 μm) was used.

<Example 1>

The adhesive layer (1) and the adhesive film (1) obtained by the above-mentioned manner are bonded to the PET film which is only one side peeled off the adhesive layer, and the support substrate is obtained by sequentially laminating the adhesive film (1). A film processing tape with a release film as shown in FIG. 1 in which an adhesive layer, an adhesive layer, and a release film are formed. This wafer processing belt was used as a sample of Example 1.

<Example 2>

Using the obtained adhesive layer (2) and the adhesive film (1), the wafer processing tape of Example 2 was produced in the same manner as in Example 1.

<Example 3>

Using the obtained adhesive layer (3) and the adhesive film (1), the wafer processing tape of Example 3 was produced in the same manner as in Example 1.

<Example 4>

Using the obtained adhesive layer (4) and the adhesive film (1), the wafer processing belt of Example 4 was produced in the same manner as in Example 1.

<Example 5>

Using the obtained adhesive layer (1) and the adhesive film (2), the wafer processing belt of Example 5 was produced in the same manner as in Example 1.

<Comparative Example 1>

Using the obtained adhesive layer (5) and the adhesive film (1), a wafer processing belt of Comparative Example 1 was produced in the same manner as in Example 1.

<Comparative Example 2>

Using the obtained adhesive layer (6) and the adhesive film (1), a wafer processing belt of Comparative Example 2 was produced in the same manner as in Example 1.

The wafer processing belts of Examples 1 to 5 and Comparative Examples 1 and 2 were subjected to the following measurement and evaluation. The results are shown in Table 1.

(surface free energy)

In the adhesive layer of each of the samples of the above examples and comparative examples, the surface not in contact with the adhesive layer was defined as the A surface, and the surface from which the adhesive layer was peeled off was defined as the B surface. At this time, in Example 5, the adhesive layer was irradiated with ultraviolet rays of 200 mJ/cm ² by an air-cooled high-pressure mercury lamp (80 W/cm, irradiation distance: 100 mm) before peeling off the adhesive layer. The contact angle of water and diiodomethane with respect to the A side and the B side was measured (droplet capacity: 2 μL of water, 3 μL of diiodomethane, reading time: 30 seconds after dropping), based on measured water and diiodomethane The contact angle was calculated using the geometric mean method by the above calculation formula.

(Peel force)

The release film of the adhesive layer of each of the samples of the examples and the comparative examples was peeled off, and the shape-retaining tape (manufactured by Sekisui Chemical Co., Ltd., trade name: Forte) was attached to the adhesive layer of the release release film by a 2 kg roller. The surface was cut into a strip having a width of 25 mm, and a test piece in which a supporting substrate, an adhesive layer, an adhesive layer, and a shape-retaining tape were sequentially laminated was prepared. The test piece produced by Strograph (VE10) grabbed by Toyo Seiki Co., Ltd. is divided into a laminated body of "support base material and adhesive layer" and "adhesive layer and shape retaining tape" at a line speed of 300 mm. /min Determines the peeling force between the adhesive layer and the adhesive layer. At this time, in Example 5, the adhesive layer was irradiated with ultraviolet rays of 200 mJ/cm ² by an air-cooled high-pressure mercury lamp (80 W/cm, irradiation distance: 100 mm) before peeling off the adhesive layer. Furthermore, the unit of the peeling force is [N/25 mm]. Further, the reason for separating the "adhesive layer and the shape-retaining tape" from the "support base material and the adhesive layer" into the "support base material and the adhesive layer" and the "adhesive layer and the shape retaining tape" is that The adhesive layer is stretched only by grasping the adhesive layer and peeling off.

(pickup)

The wafer processing belts of the respective samples of the above examples and comparative examples were heat-bonded to a silicon wafer having a thickness of 50 μm at 70 ° C for 10 seconds, and then cut into wafers of 10 mm × 10 mm. Thereafter, in Example 5, the adhesive layer was irradiated with ultraviolet rays of 200 mJ/cm ² by means of an air-cooled high-pressure mercury lamp (80 W/cm, irradiation distance: 10 cm). A pick-up test using a die bonder apparatus (manufactured by NEC Machinery, trade name: CPS-100FM) was performed on 50 wafers in the center of the wafer, and the picking success rate of the number of picked wafers was determined. At this time, among the picked-up elements, the person who kept the adhesive layer peeled off from the adhesive layer was set as the pick-up success, and the pick-up success rate was calculated. The calculation results are shown in Table 1. In Table 1, the basis of ◎, ○, △, and × (the basis of pick-up property) is as follows.

"◎" The pick-up success rate when the ejection height of the ejector pins is 0.7 mm, 0.5 mm, and 0.3 mm is 100%.

The pick-up success rate of "○" when the ejection height is 0.7mm and 0.5mm is 100%, and the pick-up success rate is less than 100% when the ejection height is 0.3mm.

The pick-up success rate of "△" when the height of the ejection is 0.7 mm is 100%, and the pick-up success rate when the ejection height is 0.5 mm and 0.3 mm is less than 100%.

The pick-up success rate of "×" when the height is 0.7mm, 0.5mm, and 0.3mm is less than 100%.

(reliability (rift rate during reflow))

The adhesive layer of the wafer processing tape of each of the examples and the comparative examples was attached to the back surface of the wafer having a thickness of 200 μm, and cut into 7.5 mm × 7.5 mm at a temperature of 160 ° C, a pressure of 0.1 MPa, and a time of 1 The condition of seconds is adhered to the silver-plated wire frame. Further, molding was carried out by using a sealing material (KE-1000SV, manufactured by Kyocera Chemical Co., Ltd., trade name) to prepare samples of 20 examples and comparative examples.

After the sealed samples of the respective examples and the comparative examples were treated in a constant temperature and humidity layer of 85 ° C / 60% RH for 196 hours, the sample was passed in such a manner that the maximum temperature of the surface of the sample became 260 ° C for 20 seconds. The above treatment was repeated three times in an IR (infrared) reflow furnace and cooled by standing at room temperature. In each of the examples and the comparative examples, the presence or absence of cracks in the 20 samples processed as described above was calculated, and the ratio of the crack-producing sample in the 20 samples was calculated, and the crack generation rate at the time of reflow was shown as reliability. In Table 1.

Further, when observing the presence or absence of cracks, each sample was observed by a transmission method using a scanning ultrasonic apparatus (Scanning Acoustic Tomograph: SAT), and all of the visible peelers were set as cracks.

Side A: No contact with the adhesive

Side B: Self-adhesive stripping surface

Comparative Examples 1 and 2 have problems in pick-up property, and Comparative Example 2 is also inferior in reliability.

On the other hand, Examples 1 to 5 were sufficient in terms of peeling force, pick-up property, and reliability. It is understood that the adhesive layer of the wafer processing tape of the present invention has sufficient adhesion even when it is bonded to the adhesive layer once.

The present invention is not limited to the details of the present invention, and is not intended to limit the invention, and is not intended to be inconsistent with the scope of the invention. Under the spirit and scope, the maximum scope should be explained.

The present invention is based on the priority of Japanese Patent Application No. 2011-141266, the entire disclosure of which is hereby incorporated by reference.

10. . . Wafer processing tape

11. . . Release PET film

12. . . Adhesive film

12a. . . Support substrate

12b. . . Adhesive layer

13. . . Subsequent layer

Fig. 1 is a cross-sectional view schematically showing a wafer processing belt of the present invention.

10. . . Wafer processing tape

11. . . Release PET film

12. . . Adhesive film

12a. . . Support substrate

12b. . . Adhesive layer

13. . . Subsequent layer

Claims (3)

A wafer processing belt characterized by sequentially laminating a support substrate, an adhesive layer, and a single layer of an adhesive layer for crimping a semiconductor element to a wiring for external connection with wiring In the member or other semiconductor element, the surface free energy difference between the surface from which the adhesive layer is peeled off from the adhesive layer and the surface not in contact with the adhesive layer is 10 mJ/m ² or less. The wafer processing tape according to the first aspect of the invention, wherein the surface free energy of the surface of the adhesive layer not in contact with the adhesive layer is 30 mJ/m ² or more and 50 mJ/m ² or less. The wafer processing belt according to claim 1 or 2, wherein the adhesive layer contains a polymer compound produced by suspension polymerization of acrylonitrile.