JP7259272B2 - Temporary fixing tape - Google Patents

Description

TECHNICAL FIELD The present invention relates to a temporary fixing tape.

2. Description of the Related Art In recent years, the demand for higher density and higher integration of semiconductor devices has increased in response to the increasing sophistication of electronic equipment and the expansion of mobile applications.

As a method of manufacturing these semiconductor devices, a semiconductor wafer in which a plurality of semiconductor elements are fabricated is diced to separate (individualize) a plurality of semiconductor elements, and then the obtained semiconductor elements are separated. , a metal lead frame or a substrate, and then sealed with a mold resin to manufacture a semiconductor device.

Here, for the purpose of realizing miniaturization of semiconductor elements, semiconductor devices, and IC packages, a semiconductor obtained by grinding and polishing the back surface of a semiconductor wafer opposite to the surface on which semiconductor elements are built Devices are being made thinner.

In order to grind and polish the back surface of a semiconductor wafer, it is necessary to temporarily fix the semiconductor wafer on the front surface side on a substrate for supporting the semiconductor wafer. As such, for example, a method has been proposed in which a semiconductor wafer is fixed on a temporary fixing tape in which a PET film as a base material is provided with an adhesive layer (see, for example, Patent Document 1).

In the grinding method of temporarily fixing such a temporary fixing tape to the surface of a semiconductor wafer having bumps (electrode pads) provided on the semiconductor element as projections on the surface, and grinding and polishing the back surface of the semiconductor wafer, To grind and polish the back surface of a semiconductor wafer with superior grinding accuracy regardless of the presence or absence of bumps on the surface of the semiconductor wafer, and to peel off the temporary fixing tape with excellent peelability after grinding and polishing. There is a demand for the development of a temporary fixing tape that can be used.

The development of such a temporary fixing tape is not limited to grinding and polishing the back surface (the other surface) of a semiconductor wafer having bumps on the front surface (one surface). The same is required in the case of grinding and polishing the back surface of another substrate provided in the substrate with the surface fixed with a temporary fixing tape.

WO2009/28068

SUMMARY OF THE INVENTION An object of the present invention is to enable grinding and polishing of a substrate with better grinding accuracy, and to remove the temporary fixing tape with excellent peelability after the grinding and polishing. It is to provide a tape.

Such objects are achieved by the present invention described in (1) to ( 7 ) below.
(1) comprising a supporting substrate and an adhesive layer laminated on one surface of the supporting substrate;
In order to process the substrate, the substrate is temporarily fixed to the supporting base via the adhesive layer, and after processing the substrate, the adhesive layer is irradiated with an energy beam to separate the substrate from the supporting base. Temporary fixing tape used for fixing,
The supporting substrate has a first layer that supports the substrate, and a second layer that is located between the first layer and the adhesive layer and has cushioning properties,
When the substrate having projections on at least one surface is bonded to the adhesive layer, the tips of the projections penetrate the adhesive layer and are located in the second layer,
When the adhesive force of the adhesive layer after irradiation with the energy beam is F1 [N/25 mm] and the adhesive force of the second layer is F2 [N/25 mm], satisfying the relationship F1>F2 ,
The temporary fixing tape , wherein the adhesive force F2 of the second layer is less than 0.003 N/25 mm .

( 2 ) The temporary fixing tape according to (1) above, wherein the second layer has an elastic modulus M2 at 45° C. of 1 MPa or more and 50 MPa or less.

( 3 ) The temporary fixing tape according to (1) or (2) above, wherein the adhesive layer has a breaking elongation G1 of 5% or more and 55% or less at 45° C. before irradiation with the energy beam.

( 4 ) The adhesive layer contains an acrylic copolymer, a cross-linking agent, an energy ray-polymerizable compound that polymerizes when irradiated with energy rays, and an energy ray polymerization initiator,
The temporary fixing tape according to any one of (1) to ( 3 ) above, which has adhesiveness before irradiation with the energy beam, and the adhesiveness is reduced by the irradiation with the energy beam.

( 5 ) The temporary fixing tape according to any one of (1) to ( 4 ) above, wherein the second layer contains a thermoplastic elastomer as a main material.

( 6 ) The temporary fixing tape according to any one of (1) to ( 5 ), wherein the substrate is a semiconductor wafer, and the protrusions are bumps provided on the semiconductor wafer.

( 7 ) The temporary fixing tape according to ( 6 ) above, wherein the processing is semiconductor wafer grinding in which the other surface of the semiconductor wafer is ground to reduce the thickness of the semiconductor wafer.

According to the temporary fixing tape of the present invention, the substrate can be ground and polished with excellent grinding accuracy, and after the substrate is ground and polished using the temporary fixing tape, the temporary fixing tape is applied. During peeling, the occurrence of contamination of the protrusions caused by the adhesive layer being caught by the protrusions of the substrate can be accurately suppressed or prevented, so that excellent peelability can be achieved.

It is a longitudinal cross-sectional view showing an example of a semiconductor device manufactured using the temporary fixing tape of the present invention. It is a longitudinal cross-sectional view for demonstrating the method to manufacture the semiconductor device shown in FIG. 1 using the tape for temporary fixation of this invention. It is a longitudinal cross-sectional view for demonstrating the method to manufacture the semiconductor device shown in FIG. 1 using the tape for temporary fixation of this invention. It is a longitudinal cross-sectional view for demonstrating the method to manufacture the semiconductor device shown in FIG. 1 using the tape for temporary fixation of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional view which shows embodiment of the tape for temporary fixation of this invention.

The temporary fixing tape of the present invention will be described in detail below.
First, prior to explaining the temporary fixing tape of the present invention, a semiconductor device manufactured using the temporary fixing tape of the present invention will be explained.

<Semiconductor device>
FIG. 1 is a longitudinal sectional view showing an example of a semiconductor device manufactured using the temporary fixing tape of the present invention. In the following description, the upper side in FIG. 1 is called "upper", and the lower side is called "lower".

As shown in FIG. 1, the semiconductor device 10 includes a semiconductor element 20 having electrode pads 26 (bumps), a sealing portion 27 (mold portion) for sealing the upper surface side of the semiconductor element 20, and a lower surface of the semiconductor element 20. and an interposer 25 (substrate) having openings 251 provided to expose the electrode pads 26 of the semiconductor element 20; Thus, a wiring 23 electrically connected to the electrode pad 26, a bump (terminal) 21 electrically connected to the wiring 23, and a coating provided to cover the wiring 23 and expose the bump 21 a portion 22;

The semiconductor element 20 (semiconductor chip) has electrode pads 26 on its lower surface side. 20 is formed in contact with the lower surface.

With the interposer 25 arranged with respect to the semiconductor element 20 at such a position, the sealing portion 27 is formed so as to cover substantially the entire upper surface side of the semiconductor element 20 and the interposer 25 .

The interposer 25 is a substrate arranged on the lower surface side of the semiconductor element 20, and its plan view shape is generally a quadrangle such as a square or a rectangle. , thereby widening the range of selectivity of the positions for forming the wiring 23 formed so as to cover the interposer 25 and, by extension, the bumps 21 provided electrically connected to the wiring 23 . . The interposer 25 is formed with a plurality of (three in this embodiment) openings (three holes) 251 corresponding to the electrode pads 26 of the semiconductor element 20 .

A wiring 23 formed in a predetermined shape is provided on the lower surface of the interposer 25 so as to fill the opening 251, and the wiring 23 is electrically connected to the electrode pad 26 at the upper end of the opening 251. Connected.

Furthermore, the bumps 21 are electrically connected to the lower surfaces of the wirings 23 , whereby the semiconductor element 20 and the bumps 21 are electrically connected via the electrode pads 26 and the wirings 23 .

A covering portion 22 having an opening 221 for exposing the bump 21 from below is provided so as to cover the wiring 23 .

In addition, among the components included in the semiconductor device 10 described above, the wiring 23 , the covering portion 22 and the bumps 21 form a wiring layer electrically connected to the semiconductor element 20 .

The semiconductor device 10 having such a configuration is manufactured, for example, as follows, using the temporary fixing tape of the present invention.

<Method for manufacturing a semiconductor device>
2 to 4 are longitudinal sectional views for explaining a method of manufacturing the semiconductor device shown in FIG. 1 using the temporary fixing tape of the present invention. In the following description, the upper side in FIGS. 2 to 4 is called "upper", and the lower side is called "lower".

[1A] First, a provisional semiconductor wafer 7 in which a plurality of semiconductor elements 20 are built, a supporting substrate 82, and an adhesive layer 81 laminated on the upper surface (one surface) of the supporting substrate 82. A fixing tape 200 is prepared and laminated ( affix) (see FIG. 2(a)).
That is, the semiconductor wafer 7 is temporarily fixed to the temporary fixing tape 200 .

In this step, prior to temporarily fixing the temporary fixing tape 200 to the semiconductor wafer 7, an elongation force is applied to the temporary fixing tape 200 to extend the temporary fixing tape 200 in at least one direction. The temporary fixing tape 200 is temporarily fixed to the wafer 7 for the temporary fixing. In this case, when the temporary fixing tape 200 has a disc shape corresponding to the shape of the semiconductor wafer 7, the direction in which the temporary fixing tape 200 is applied with the elongating force is radial from the center of the temporary fixing tape 200. It may be in the forming direction or in one direction passing through the center of the temporary fixing tape 200 . Furthermore, when the planar shape of the temporary fixing tape 200 is a rectangular sheet shape, it may be in one or both of the longitudinal direction and the lateral direction.

In addition, the plurality of semiconductor elements 20 are formed on the surface 71 side of the semiconductor wafer 7, and the electrode pads 26 (not shown in FIGS. 2 and 3) of the semiconductor elements 20 are positioned on the surface 71 side, The semiconductor wafer 7 has an uneven surface 71 having a plurality of projections caused by the electrode pads 26 (bumps).

[2A] Next, a temporary fixing tape 200 (temporary fixing tape of the present invention) is attached to the back surface (processed surface) 72 opposite to the front surface 71 of the semiconductor wafer 7 on the front surface 71 side. Grind or polish (back grind) (see FIG. 2(c)).

Grinding and polishing of the back surface 72 of the semiconductor wafer 7 can be performed using, for example, a grinding apparatus (grinder), as shown in FIG. 2(b).

By grinding and polishing the back surface 72, the thickness of the semiconductor wafer 7 is preferably set to about 50 μm or more and 600 μm or less, more preferably 50 μm or more and 200 μm or less, although it varies depending on the electronic equipment to which the semiconductor device 10 is applied. set to an extent. As a result, the thickness of the semiconductor element 20 to be obtained is reduced, and the semiconductor device 10 including the semiconductor element 20 and furthermore the IC package are reduced in size.

Thus, by using the temporary fixing tape 200 of the present invention when grinding/polishing the semiconductor wafer 7, the semiconductor wafer 7 can be ground with superior grinding accuracy, and the grinding/polishing can be Later, the temporary fixing tape 200 can be peeled off with excellent peelability, but the detailed description thereof will be given later.

[3A] Next, an adhesive tape 100 for semiconductor wafer processing having a base material 4 and an adhesive layer 2 laminated on the upper surface of the base material 4 (hereinafter sometimes simply referred to as "adhesive tape 100") is prepared. The adhesive tape 100 is prepared and placed on a dicer table (not shown), and the back surface (the surface opposite to the surface 71 on which the temporary fixing tape 200 is laminated) 72 is attached to the center 122 of the adhesive layer 2. The semiconductor wafer 7 is laminated (attached) by placing it on top and lightly pressing it (see FIG. 2(d)).

Alternatively, the adhesive tape 100 may be placed on the dicer table after the semiconductor wafer 7 is attached in advance.

[4A] Next, by irradiating the adhesive layer 81 with energy rays through the support base material 82 to reduce the adhesive strength of the adhesive layer 81 to the semiconductor wafer 7, as shown in FIG. The temporary fixing tape 200 is peeled off from the semiconductor wafer 7 .
That is, the temporary fixing state of the semiconductor wafer 7 to the temporary fixing tape 200 is released.

Examples of energy rays include ultraviolet rays, electron beams, particle beams such as ion beams, and combinations of two or more of these energy rays. Among these, it is particularly preferable to use ultraviolet rays. The ultraviolet rays can efficiently reduce the adhesiveness of the adhesive layer 81 to the semiconductor wafer 7 .

[5A] Next, the outer peripheral portion 121 of the adhesive layer 2 is fixed by the wafer ring 9, and then the semiconductor wafer 7 is cut (diced) using a dicing saw (blade) (not shown) to obtain the semiconductor wafer 7. Individualize (see FIG. 3(a)).

As a result, a plurality of semiconductor elements 20 are formed on the adhesive tape 100 while adhering to the adhesive layer 2 .

Further, the cutting of the semiconductor wafer 7 using the blade is carried out so as to reach halfway in the thickness direction of the base material 4 as shown in FIG. 3(a). As a result, the individualization of the semiconductor wafer 7 can be reliably performed.

[6A] Next, by applying energy to the adhesive layer 2 of the adhesive tape 100, the adhesiveness of the adhesive layer 2 to the semiconductor elements 20 (divided semiconductor wafers 7) is reduced.
As a result, the adhesive layer 2 and the semiconductor element 20 are separated from each other.

The method of applying energy to the adhesive layer 2 is not particularly limited, but examples thereof include a method of irradiating the adhesive layer 2 with energy rays, a method of heating the adhesive layer 2, and the like.

Moreover, as the energy ray, the same one as described in the step [4A] can be used.

[7A] Next, the adhesive tape 100 is radially stretched by an expanding device (not shown) to open the semiconductor elements 20 (divided semiconductor wafers 7) at regular intervals (see FIG. 3(b)), and then The semiconductor element 20 is pushed up with a needle or the like, and in this state is picked up by suction or the like with a vacuum collet or air tweezers (see FIG. 3(c)).

[8A] Next, the picked-up semiconductor element 20 is placed on an interposer 25 (substrate) in which openings 251 are formed in advance at positions corresponding to the electrode pads 26 of the semiconductor element 20 (FIG. 4 ( a) see).

The interposer 25 is not particularly limited. ) is used.

[9A] Next, a sealing portion 27 is formed on the upper surface of the interposer 25, that is, the surface on which the semiconductor element 20 is arranged, so as to cover the interposer 25 and the semiconductor element 20 (Fig. 4(b)). )reference).

The method for forming the sealing portion 27 is not particularly limited. After bringing the upper surface of the poser 25 into contact with the epoxy resin composition, a method of heating and compressing the epoxy resin composition using a mold (compression molding method) can be used.

[10A] Next, on the side of the interposer 25 opposite to the semiconductor element 20, a wiring 23 patterned into a predetermined shape is opened so as to be electrically connected to the electrode pad 26 exposed in the opening 251. The portion 251 is filled in and connected to the electrode pad 26 (see FIG. 4(c)).
The wiring 23 can be formed using various plating methods, for example.

[11A] Next, on the side of the interposer 25 opposite to the semiconductor element 20, a covering portion 22 having an opening 221 is formed so that a portion of the wiring 23 is exposed (see FIG. 4D). ).

The openings 221 are formed so as to correspond to the positions where the bumps 21 are formed in the next step [12A].

The coating portion 22 is formed by, for example, supplying a liquid material (varnish) containing a photosensitive insulating material to the surface of the interposer 25 opposite to the semiconductor element 20 using a coating method or the like, Next, after exposure through a photomask corresponding to the shape of the opening 221 to be formed, the area to be the opening 221 is removed with a developing solution (etching solution).

[12A] Next, the bumps 21 are formed so as to be electrically connected to the wirings 23 exposed from the openings 221 (see FIG. 4(e)).

Here, by connecting the electrode pads 26 and the bumps 21 via the wirings 23 as in the present embodiment, the bumps 21 are separated from the openings 251 in the planar direction of the interposer 25 . Can be placed in different positions. In other words, the bumps 21 and the openings 251 can be arranged so that their centers do not overlap. Therefore, the bumps 21 can be formed at desired positions on the lower surface of the resulting semiconductor device 10 .

The method of bonding the bumps 21 to the wirings 23 is not particularly limited.

Moreover, as a constituent material of the bumps 21, for example, brazing materials such as solder, silver brazing, copper brazing, phosphorous copper brazing, and the like can be mentioned.
Through the steps described above, the semiconductor device 10 is manufactured.

Next, the temporary fixing tape 200 (the temporary fixing tape of the present invention) used in the manufacturing method of the semiconductor device 10 will be described.

<Temporary fixing tape>
FIG. 5 is a longitudinal sectional view showing an embodiment of the temporary fixing tape of the present invention. In the following description, the upper side in FIG. 5 is called "upper", and the lower side is called "lower".

As shown in FIG. 5, the temporary fixing tape 200 includes a support base material 82 and an adhesive layer 81 laminated on the upper surface (one side) of the support base material 82, and the electrode pads 26 are provided on one side. In order to process the semiconductor wafer 7 on the surface of the semiconductor wafer 7, the semiconductor wafer 7 is temporarily fixed to the support base material 82 via the adhesive layer 81, and after the semiconductor wafer 7 is processed, the adhesive layer 81 is irradiated with energy rays. It is used for separating the semiconductor wafer 7 from the support base material 82 by pressing the support base material 82. In the present invention, the support base material 82 includes the first layer 821 for supporting the semiconductor wafer 7 and the first layer 821 for supporting the semiconductor wafer 7. It has a second layer 822 which is located between the layer 821 and the adhesive layer 81 and has a cushioning property, and when the semiconductor wafer 7 is bonded to the adhesive layer 81 on the one surface side, the electrode pad 26 penetrates the adhesive layer 81 and is located in the second layer 822 having cushioning properties, and the adhesive force of the adhesive layer 81 after irradiation with the energy beam is F1 [N/25 mm], and the The second layer 822 satisfies the relationship of F1>F2, where F2 [N/25 mm] is the adhesive force of the second layer 822 .

In this way, when the semiconductor wafer 7 is temporarily fixed using the temporary fixing tape 200 , in the present invention, the electrode pad 26 penetrates the adhesive layer 81 and has its tip inside the second layer 822 . It is located in In this state, the semiconductor wafer 7 is ground and polished in the step [2A], so that a uniform pressing force can be applied to the entire back surface 72 of the semiconductor wafer 7. Therefore, the thickness can be reduced to a uniform thickness without causing thickness unevenness. Therefore, the grinding precision of the semiconductor wafer 7 can be improved.

Furthermore, in the present invention, the relationship F1>F2 is satisfied when the electrode pad 26 penetrates the adhesive layer 81 and the tip of the electrode pad 26 is located in the second layer 822. In [4A], when the temporary fixing tape 200 is peeled off, the occurrence of contamination of the electrode pads 26 due to the adhesion layer 81 and the second layer 822 being caught on the electrode pads 26 can be accurately suppressed or prevented. can. Therefore, the temporary fixing tape 200 can be peeled off with excellent peelability without affecting the conductive properties of the electrode pads 26 .

Hereinafter, the support base material 82 and the adhesive layer 81 of the temporary fixing tape (back grind tape) 200 will be described in detail.

<Support base material 82>
As described above, in the present invention, the supporting base material 82 is composed of a laminate having a first layer 821 that supports the semiconductor wafer 7 and a second layer 822 that has cushioning properties. This support base material 82 serves as a support layer (support substrate) that supports the semiconductor wafer 7 via the adhesive layer 81 when the back surface 72 of the semiconductor wafer 7 is ground and polished in the step [2A]. function is mainly exhibited by the first layer 821, and there is no difference between the position corresponding to the electrode pad 26 (projection) and the position not corresponding to the electrode pad 26 (projection) on the surface 71 side of the semiconductor wafer 7. The second layer 822 mainly functions as a cushion layer that applies a uniform pressing force over the entire grinding surface (rear surface 72) on which the semiconductor wafer 7 is ground.

The first layer 821 and the second layer 822 will be described in detail below.
<<first layer 821>>
The first layer 821 has a function of supporting the adhesive layer 81 provided on the supporting base material 82 and, by extension, the semiconductor wafer 7 attached on the adhesive layer 81 .

The first layer 821 is set to have a higher elastic modulus than the second layer 822, and preferably contains thermoplastic resin as a main material, for example.

Examples of thermoplastic resins include polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polyethylene, polyvinyl chloride, polypropylene (PP), polystyrene, polyarylate, polycarbonate and Polyamide and the like can be mentioned, and one or more of these can be used in combination.

In addition to the thermoplastic resin, the first layer 821 contains softening agents, fillers, plasticizers, antioxidants, light stabilizers, lubricants, and neutralizing agents described later for the second layer 822 . , colorants, and other additives may be added.

Note that the first layer 821 may be composed of a laminate (multilayer body) in which a plurality of layers composed of different resin materials are laminated. Further, it may be composed of a blend film obtained by dry-blending the resin material.

The elastic modulus of the first layer 821 at 25° C. (normal temperature) is preferably 1000 MPa or more and 5000 MPa or less, more preferably 1500 MPa or more and 4300 MPa or less. As a result, the semiconductor wafer 7 can be more reliably supported during the grinding/polishing of the semiconductor wafer 7 in the step [2A].

Although the thickness of the first layer 821 is not particularly limited, it is preferably 10 μm or more and 120 μm or less, and more preferably 20 μm or more and 100 μm or less. When the thickness of the first layer 821 is within this range, the grinding and polishing of the semiconductor wafer 7 in the step [2A] can be performed with excellent workability. Moreover, the semiconductor wafer 7 can be supported more reliably during the grinding/polishing of the semiconductor wafer 7 in the step [2A].

<<second layer 822>>
As described above, when the semiconductor wafer 7 is ground, the second layer 822 has a projection (electrode pad 26) on the surface 71 of the semiconductor wafer 7. The bottom surface of the second layer 822 follows the unevenness formed by the second layer 822 and is configured as a flat surface. Therefore, the second layer 822 does not cause any difference between the positions corresponding to the electrode pads 26 (projections) on the front surface 71 side of the semiconductor wafer 7 and the positions not corresponding to the ground surface of the semiconductor wafer 7 . It has a function as a cushion layer for applying a uniform pressing force over the entire surface of (back surface 72) and grinding the back surface 72 with higher grinding accuracy.

The second layer 822 preferably contains, for example, a thermoplastic elastomer as its main material.

Examples of thermoplastic elastomers include styrene thermoplastic elastomers, olefinic thermoplastic elastomers such as polypropylene thermoplastic elastomers, polyester thermoplastic elastomers, polyurethane thermoplastic elastomers, polyamide thermoplastic elastomers, and the like. One or more of these can be used in combination.

In addition to the thermoplastic elastomer, the second layer 822 may include softeners such as mineral oil and process oil, fillers such as calcium carbonate, silica, talc, mica and clay, petroleum resins, hydrocarbon resins, Additives such as terpene resins, rosin esters, tackifiers such as phenolic resins, and plasticizers such as phthalates and amorphous polypropylene may be added.

Examples of styrene-based thermoplastic elastomers (TPS) include styrene-butadiene-styrene block copolymer (SBS), partially hydrogenated styrene-butadiene-styrene block copolymer (SBS), styrene-butadiene- Fully hydrogenated styrene block copolymer (SBS), styrene-isobutylene-styrene block copolymer (SIBS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-isoprene-styrene (SIS) , styrene-ethylene-propylene-butylene block copolymer (SEPS), etc. Among these, partially hydrogenated styrene-butadiene-styrene block copolymer (SBS), styrene-butadiene-styrene block copolymer It is preferably at least one of a fully hydrogenated product of coalescence (SBS) and a styrene-isobutylene-styrene block copolymer (SIBS).

In addition, since these thermoplastic elastomers are materials that can transmit energy rays such as light (visible light, near-infrared rays, ultraviolet rays), X-rays, and electron beams, in the step [4A], the energy rays are first The light can be transmitted through the second layer 822 from the second layer 822 side to irradiate the adhesive layer 81 .

Furthermore, the second layer 822 may contain antioxidants, light stabilizers, lubricants, dispersants, neutralizers, colorants, and the like.

Moreover, the second layer 822 preferably has exposed functional groups such as hydroxyl groups and amino groups that are reactive with the constituent materials contained in the adhesive layer 81 on its surface. In this case, for example, the functional groups can be exposed by subjecting the surface of the second layer 822 to corona treatment.

Furthermore, the second layer 822 may be composed of a laminate (multilayer body) in which a plurality of layers composed of different resin materials are laminated. Further, it may be composed of a blend film obtained by dry-blending the resin material.

The elastic modulus of the second layer 822 at 45° C. is preferably 1 MPa or more and 50 MPa or less, more preferably 5 MPa or more and 11 MPa or less. As a result, when the semiconductor wafer 7 is temporarily fixed to the temporary fixing tape 200 in the step [1A], the tip of the electrode pad 26 (protrusion) protruding from the surface 71 of the semiconductor wafer 7 is attached to the adhesive layer. While penetrating the adhesive layer 81 in the thickness direction of 81, the shape of the upper surface of the second layer 822 itself can more reliably follow (match) the shape of the electrode pad 26 (protrusion).

The elastic modulus of the second layer 822 at 25° C. (room temperature) is preferably 6 MPa or more and 100 MPa or less, more preferably 10 MPa or more and 16 MPa or less. As a result, when the semiconductor wafer 7 is ground/polished in the step [2A], the second layer 822 is allowed to more reliably function as a cushion layer, and the entire back surface 72 of the semiconductor wafer 7 is covered with the second layer 822. Since a more uniform pressing force can be applied over the entire length, the grinding precision of the semiconductor wafer 7 can be further improved.

Furthermore, when the second layer 822 has an elastic modulus of M1 [MPa] at 25° C. (room temperature) and an elastic modulus of M2 [MPa] at 45° C., M1−M2 is 1 MPa or more and 50 MPa or less. , and more preferably 2 MPa or more and 5 MPa or less. Thereby, the effect obtained by setting the elastic modulus of the second layer 822 at 25° C. (room temperature) and 45° C. within the above range can be exhibited more remarkably.

The thickness T2 [μm] of the second layer 822 is −60<T2− when the height of the electrode pads 26 (projections) formed on the surface 71 of the semiconductor wafer 7 is H [μm]. It is preferable to satisfy the relationship 2H<200, and it is more preferable to satisfy the relationship 0<T2-2H<50. By satisfying this relationship, when the semiconductor wafer 7 is ground and polished in the step [2A], the electrode pad 26 penetrates the adhesive layer 81 and the tip of the electrode pad 26 is aligned with the second layer 822. Since the second layer 822 can reliably function as a cushion layer while being positioned inside, the entire surface of the back surface 72 of the semiconductor wafer 7 can be thinned with a more uniform thickness.

Specifically, the thickness of the second layer 822 is, for example, preferably 50 μm or more and 600 μm or less, and more preferably 200 μm or more and 550 μm or less. When the thickness of the second layer 822 is within this range, the second layer 822 can reliably perform the function as the cushion layer, so that the entire surface of the back surface 72 of the semiconductor wafer 7 can be covered more. It can be made thin with a uniform thickness.

<Adhesive layer 81>
The adhesive layer 81 is attached to the front surface 71 of the semiconductor wafer 7 when the back surface 72 of the semiconductor wafer 7 is ground and polished in the step [2A], and the semiconductor wafer 7 is supported through this layer. It has a function to be supported by the base material 82, and in the present invention, when the temporary fixing tape 200 is attached (bonded) to the surface 71 of the semiconductor wafer 7, the electrode pads 26 (bumps) of the semiconductor integrated circuit are attached. The resulting protrusion penetrates the adhesive layer 81 and its tip is positioned within the second layer 822 . In this way, the projection penetrates the adhesive layer 81 at the position where the projection is formed on the surface 71 of the semiconductor wafer 7, and the tip of the penetration projection is located in the second layer 822. With this structure, the second layer 822 can reliably exhibit its function as a cushion layer. Therefore, in the step [2A], the thickness of the semiconductor wafer 7 can be reduced while a uniform pressing force is applied over the entire back surface 72 of the semiconductor wafer 7. FIG.

Further, in the step [4A], the adhesive layer 81 is irradiated with energy rays to reduce the adhesiveness to the semiconductor wafer 7, and as a result, the adhesion between the adhesive layer 81 and the semiconductor wafer 7 is reduced. It will be in a state in which peeling can be easily caused between them.

In the present invention, when the adhesive force of the adhesive layer 81 after irradiation with energy rays is F1 [N/25 mm] and the adhesive force of the second layer 822 is F2 [N/25 mm], F1>F2. happy with the relationship. That is, the adhesive force F2 of the second layer 822 is smaller than the adhesive force F1 of the adhesive layer 81 .

Here, in the present invention, as described above, in the step [1A], when the semiconductor wafer 7 is temporarily fixed using the temporary fixing tape 200, the projections derived from the electrode pads 26 (bumps) are adhered. It penetrates the layer 81 and its tip is located in the second layer 822 . Therefore, in this state, when the temporary fixing tape 200 is peeled off in step [4A], the electrode pads 26 protruding as protrusions from the surface 71 of the semiconductor wafer 7 have an adhesive force lower than the adhesive force F1. Since the second layer 822 having the force F2 is in contact with the electrode pad 26, the occurrence of contamination of the electrode pad 26 due to the adhesion layer 81 and the second layer 822 being caught on the electrode pad 26 can be suppressed or prevented. can be prevented. Therefore, the temporary fixing tape 200 can be peeled off with excellent peelability without affecting the conductive properties of the electrode pads 26 .

Such an adhesive layer 81 includes, for example, (1) an acrylic copolymer, (2) an energy ray polymerizable compound that is polymerized by irradiation with an energy ray, (3) an energy ray polymerization initiator, and (4) It is composed of a resin composition containing a cross-linking agent as a main material.

Each component contained in the resin composition will be described in detail below.
(1) Acrylic Copolymer The acrylic copolymer (acrylic resin) has adhesiveness, and the adhesion to the semiconductor wafer 7 is imparted to the adhesive layer 81 before the energy beam is applied to the adhesive layer 81 . It is contained in the resin composition to impart Further, by including an acrylic copolymer in the resin composition, it is possible to improve the heat resistance of the adhesive layer 81 .

This acrylic copolymer refers to a copolymer whose base polymer is a polymer (homopolymer or copolymer) containing (meth)acrylic acid ester as a main monomer component.

The (meth)acrylic acid ester is not particularly limited, but examples include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, and butyl (meth)acrylate. , isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, (meth)acrylate Octyl acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, (meth) ) undecyl acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, (meth) (meth)acrylic acid alkyl esters such as octadecyl acrylate, (meth)acrylic acid cycloalkyl esters such as cyclohexyl (meth)acrylate, (meth)acrylic acid aryl esters such as phenyl (meth)acrylate, etc. One or more of these can be used in combination. Among these, (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate is preferably (Meth)acrylic acid alkyl esters, in particular, are excellent in heat resistance, and can be obtained relatively easily and inexpensively.

In this specification, (meth)acrylic acid ester is used in the sense of including both acrylic acid ester and methacrylic acid ester.

The acrylic copolymer may also contain a copolymerizable monomer in addition to the (meth)acrylic acid ester as a monomer component constituting the polymer.

Examples of such copolymerizable monomers include, but are not limited to, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, (meth) Hydroxyl group-containing monomers (hydroxyl group-containing (meth)acrylates) such as 6-hydroxyhexyl acrylate, epoxy group-containing monomers such as glycidyl (meth)acrylate, (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid , crotonic acid, carboxyl group-containing monomers such as isocrotonic acid, maleic anhydride, acid anhydride group-containing monomers such as itaconic anhydride, (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-butyl ( Amide group-containing monomers (amide group-containing ( meth)acrylate), amino group-containing monomers such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate, and (meth)acrylonitrile cyano group-containing monomers, alkoxy group-containing monomers such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate, N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N- Vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-vinylmorpholine, N-vinylcaprolactam, N-(meth)acryloylmorpholine, etc. and the like having a nitrogen atom-containing ring, and these can be used alone or in combination of two or more. Among these, at least one of carboxyl group-containing monomers and amide group-containing monomers is preferably included as the copolymerizable monomer. As a result, the electrode pads 26 protruding from the surface 71 of the semiconductor wafer 7 can reliably penetrate the adhesive layer 81 containing a copolymer derived from these monomers as an acrylic copolymer.

The content of these copolymerizable monomers is preferably 40% by weight or less, more preferably 10% by weight or less, relative to all monomer components constituting the acrylic copolymer.

Further, the copolymerizable monomer may be contained at the end of the main chain in the polymer constituting the acrylic copolymer, or contained in the main chain, furthermore, at the end of the main chain. It may be contained both in the main chain and in the main chain.

Furthermore, the copolymerizable monomer may contain a polyfunctional monomer for the purpose of cross-linking between polymers.

Examples of polyfunctional monomers include 1,6-hexanediol (meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, and neopentyl glycol di(meth)acrylate. , pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, glycerin di(meth)acrylate, epoxy (meth)acrylate, polyester ( Meth)acrylate, urethane (meth)acrylate, divinylbenzene, butyl di(meth)acrylate, hexyl di(meth)acrylate and the like can be mentioned, and one or more of these can be used in combination.

Such an acrylic copolymer (polymer) can be produced by polymerizing a single monomer component or a mixture of two or more monomer components. Moreover, polymerization of these monomer components can be carried out using a polymerization method such as a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a suspension polymerization method, or the like.

Acrylic copolymers obtained by polymerizing the monomer components described above include acrylic copolymers having a carbon-carbon double bond in the side chain, in the main chain, or at the end of the main chain. (also referred to as "double bond-introduced acrylic copolymer"). When the acrylic copolymer is a double bond-introduced acrylic copolymer, even if the addition of the energy ray-polymerizable compound (curable resin) described later is omitted, the resulting adhesive layer 81 has the above-described The function of the adhesive layer 81 can be exhibited.

The weight average molecular weight of the acrylic copolymer is preferably set to 300,000 to 5,000,000, more preferably set to 400,000 to 3,000,000, further preferably set to 500,000 to 1,500,000. By setting the weight average molecular weight of the acrylic copolymer within the above range, the surface 71 with which the adhesive layer 81 contacts when the temporary fixing tape 200 is peeled off from the semiconductor wafer 7 in the step [4A]. It is possible to appropriately suppress or prevent part of the adhesive layer 81 from remaining on the surface.

In addition, the acrylic copolymer has functional groups (reactive functional group). As a result, the cross-linking agent and the energy ray polymerization initiator are linked to the acrylic resin, which is the polymer component, so that leakage of the cross-linking agent and the energy ray polymerization initiator from the adhesive layer 81 can be accurately suppressed or prevented. . As a result, the adhesiveness of the adhesive layer 81 to the surface 71 of the semiconductor wafer 7 is reliably lowered by the energy beam irradiation in the step [4A].

49. The acrylic copolymer is preferably blended in the adhesive layer 81 (resin composition) at 30 wt % or more and 70 wt % or less, more preferably 35 wt % or more and 65 wt % or less. More preferably, it is blended at 5 wt%.

By adjusting the blending amount of the acrylic copolymer as described above, the peeling of the temporary fixing tape 200 from the semiconductor wafer 7 in the step [4A] can be performed by the semiconductor wafer 7 with which the adhesive layer 81 contacts. The adhesive layer 81 does not partially remain from the surface 71 of the , and can be performed with excellent accuracy. Further, in the step [1A], when the temporary fixing tape 200 was attached to the semiconductor wafer 7, the electrode pad 26 penetrated the adhesive layer 81 and its tip was located in the second layer 822. state can be Therefore, when grinding and polishing the back surface 72 of the semiconductor wafer 7 in the step [2A], it is possible to more accurately suppress or prevent the grinding water from entering the electrode pad 26, The thinning can be achieved in a state where the entire surface of the back surface 72 of the wafer 7 is thinned with a uniform thickness.

(2) Energy ray-polymerizable compound The energy ray-polymerizable compound is polymerized by energy ray irradiation and, as a result, has curability. Due to the curing caused by this polymerization, the acrylic copolymer is taken into the crosslinked structure of the energy ray-polymerizable compound, and as a result, the adhesive strength of the adhesive layer 81 is lowered.

Such an energy ray-polymerizable compound has, for example, at least two or more polymerizable carbon-carbon double bonds as functional groups in the molecule, which can be three-dimensionally crosslinked by irradiation with an energy ray such as an ultraviolet ray or an electron beam. Low molecular weight compounds are used.

Specifically, for example, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, 1,4-butylene glycol di(meth)acrylate ) acrylates, polyethylene glycol di(meth)acrylates, esters of (meth)acrylic acid and polyhydric alcohols such as glycerin di(meth)acrylates, ester acrylate oligomers, 2-propenyl-di-3-butenyl cyanurate Cyanurate compounds having a carbon-carbon double bond-containing group such as tris (2-acryloxyethyl) isocyanurate, tris (2-methacryloxyethyl) isocyanurate, 2-hydroxyethyl bis (2-acrylic oxyethyl) isocyanurate, bis(2-acryloxyethyl) 2-[(5-acryloxyhexyl)-oxy]ethyl isocyanurate, tris(1,3-diacryloxy-2-propyl-oxycarbonylamino-n-hexyl ) isocyanurate, tris(1-acryloxyethyl-3-methacryloxy-2-propyl-oxycarbonylamino-n-hexyl)isocyanurate, tris(4-acryloxy-n-butyl)isocyanurate, and the like. Isocyanurate-based compounds having a heavy bond-containing group, commercially available oligoester acrylates, aromatic, aliphatic urethane acrylates, etc., may be used alone or in combination of two or more thereof. be able to. Among these, it is preferable to include an oligomer having 6 or more functional groups, more preferably an oligomer having 15 or more functional groups. Thereby, the energy ray-polymerizable compound can be cured more reliably by the irradiation of the energy ray. Moreover, such an energy ray-polymerizable compound is preferably a urethane acrylate oligomer. Accordingly, the adhesive layer 81 can be given appropriate flexibility. Therefore, in the step [1A], when temporarily fixing the semiconductor wafer 7 using the temporary fixing tape 200, the protrusions derived from the electrode pads 26 (bumps) penetrate the adhesive layer 81, and the electrode pads 26 (protrusions) can be located in the second layer 822 .

Although the urethane acrylate is not particularly limited, examples include polyol compounds such as polyester type or polyether type and polyvalent isocyanate compounds (e.g., 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,6-tolylene diisocyanate, isocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane 4,4-diisocyanate, etc.) and a terminal isocyanate urethane prepolymer having a hydroxyl group ( Examples include those obtained by reacting meth)acrylates (eg, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, polyethylene glycol (meth)acrylate, etc.).

The energy ray-polymerizable compound preferably has a weight average molecular weight of about 100 to 10,000, more preferably about 200 to 5,000. Furthermore, the number of functional groups in the energy ray-polymerizable compound is preferably about 1 to 10 functional groups, more preferably about 2 to 6 functional groups. By satisfying this relationship, the above effects can be exhibited more remarkably.

42. The energy ray-polymerizable compound is preferably blended in the adhesive layer 81 (resin composition) at 30 wt % or more and 60 wt % or less, more preferably 35 wt % or more and 55 wt % or less. More preferably, it is blended at 4 wt%.

By adjusting the blending amount of the energy beam polymerizable compound as described above, the peeling of the temporary fixing tape 200 from the semiconductor wafer 7 in the step [4A] can be performed by the semiconductor wafer 7 with which the adhesive layer 81 is in contact. The adhesive layer 81 does not partially remain from the surface 71 of the , and can be performed with excellent accuracy. Further, in the step [1A], when the temporary fixing tape 200 was attached to the semiconductor wafer 7, the electrode pad 26 penetrated the adhesive layer 81 and its tip was located in the second layer 822. state can be Therefore, when grinding and polishing the back surface 72 of the semiconductor wafer 7 in the step [2A], it is possible to more accurately suppress or prevent the grinding water from entering the electrode pad 26, The thinning can be achieved in a state where the entire surface of the back surface 72 of the wafer 7 is thinned with a uniform thickness.

When a double bond-introduced acrylic resin is used as the acrylic resin described above, the energy ray-polymerizable compound has a carbon-carbon double bond in the side chain, in the main chain, or in the main chain. When one having a terminal is used, its addition to the resin composition can be omitted. This is because, when the acrylic resin is a double bond-introduced acrylic resin, the adhesion layer 81 is activated by the function of the carbon-carbon double bond of the double bond-introduced acrylic resin by irradiation with energy rays. hardens, thereby reducing the adhesive strength of the adhesive layer 81 .

(3) Energy Ray Polymerization Initiator The adhesive layer 81 loses adhesion to the semiconductor wafer 7 when irradiated with energy rays. preferably contains an energy ray polymerization initiator (photopolymerization initiator) in order to facilitate initiation of polymerization of the energy ray polymerizable compound.

Energy ray polymerization initiators include, for example, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl- 1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, benzyldiphenyl sulfide , tetramethylthiuram monosulfide, 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, 1-hydroxycyclohexylphenyl ketone, Michler's ketone, acetophenone, methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1-[4-(methylthio)-phenyl]-2 - morpholinopropane-1, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl, benzoin, dibenzyl, α-hydroxycyclohexylphenyl ketone, benzyldimethylketal, 2-hydroxymethylphenylpropane, 2-naphthalenesulfonyl chloride, 1-phenone-1,1-propanedione-2-(o-ethoxycarbonyl)oxime, benzophenone, benzoylbenzoic acid, 4,4′-dimethylaminobenzophenone, 4,4′-diethylaminobenzophenone, 4,4'-dichlorobenzophenone, 3,3'-dimethyl-4-methoxybenzophenone, o-acryloxybenzophenone, p-acryloxybenzophenone, o-methacryloxybenzophenone, p-methacryloxybenzophenone, p-(meth)acryl Benzophenone-4-carboxylic acid of acrylates such as oxyethoxybenzophenone, 1,4-butanediol mono(meth)acrylate, 1,2-ethanediol mono(meth)acrylate, 1,8-octanediol mono(meth)acrylate Ester, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2 , 4-diisopropylthioxanthone, azobisisobutyronitrile, β-chloroanthraquinone, camphorquinone, halogenated ketones, acylphosphinoxide, acylphosphonate, polyvinylbenzophenone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, Diethylthioxanthone, 2-ethylanthraquinone, t-butylanthraquinone, 2,4,5-triarylimidazole dimer, and the like can be mentioned, and one or more of these can be used in combination.

Among these, benzophenone derivatives and alkylphenone derivatives are preferred. These compounds have a reactive functional group that generates a hydroxyl group in the molecule, and can be linked to an acrylic copolymer or an energy ray-polymerizable compound via this reactive functional group. The function as an energy ray polymerization initiator can be exhibited more reliably.

The energy ray polymerization initiator is preferably blended in the adhesive layer 81 (resin composition) at 1 wt % or more and 5 wt % or less, more preferably 1.5 wt % or more and 4.5 wt % or less. Preferably, it is more preferably blended at 2.8 wt%.

By adjusting the blending amount of the energy beam polymerization initiator as described above, the peeling of the temporary fixing tape 200 from the semiconductor wafer 7 in the step [4A] can be performed by the semiconductor wafer 7 with which the adhesive layer 81 contacts. The adhesive layer 81 does not partially remain from the surface 71 of the , and can be performed with excellent accuracy. Further, in the step [1A], when the temporary fixing tape 200 was attached to the semiconductor wafer 7, the electrode pad 26 penetrated the adhesive layer 81 and its tip was located in the second layer 822. state can be Therefore, when grinding and polishing the back surface 72 of the semiconductor wafer 7 in the step [2A], it is possible to more accurately suppress or prevent the grinding water from entering the electrode pad 26, The thinning can be achieved in a state where the entire surface of the back surface 72 of the wafer 7 is thinned with a uniform thickness.

(4) Cross-linking agent The cross-linking agent is included in the resin composition to improve the curability of the energy ray-polymerizable compound.

The cross-linking agent is not particularly limited. Examples include metal chelate-based cross-linking agents, acid anhydride-based cross-linking agents, polyamine-based cross-linking agents, and carboxyl group-containing polymer-based cross-linking agents. Among these, isocyanate-based cross-linking agents are preferred.

Examples of the isocyanate-based cross-linking agent include, but are not limited to, a polyisocyanate compound of a polyisocyanate, a trimer of the polyisocyanate compound, and a trimer of a terminal isocyanate compound obtained by reacting a polyisocyanate compound with a polyol compound. Alternatively, a blocked polyisocyanate compound obtained by blocking a terminal isocyanate urethane prepolymer with phenol, oximes, or the like can be used.

Examples of polyvalent isocyanates include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane -2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, 4,4'-diphenyl ether diisocyanate, 4 2,6 -condensation compounds of tolylene diisocyanate and trimethylolpropane, etc., and one or more of these can be used in combination. Among these, 2,4-tolylene diisocyanate, diphenylmethane-4,4′-diisocyanate, hexamethylene diisocyanate, condensation compounds of 2,4-tolylene diisocyanate and trimethylolpropane, and 2,6-tolylene diisocyanate and trimethylolpropane At least one polyvalent isocyanate selected from the group consisting of condensation compounds of methylolpropane is preferred.

In addition, the cross-linking agent is preferably blended in the adhesive layer 81 (resin composition) at 0.5 wt % or more and 6.5 wt % or less, and is blended at 1.0 wt % or more and 5.5 wt % or less. More preferably, it is more preferably blended at 5.3 wt%. By adjusting the blending amount of the cross-linking agent as described above, the peeling of the temporary fixing tape 200 from the semiconductor wafer 7 in the step [4A] can be controlled by the surface 71 of the semiconductor wafer 7 with which the adhesive layer 81 contacts. Therefore, a part of the adhesive layer 81 does not remain, and the operation can be performed with excellent accuracy. Further, in the step [1A], when the temporary fixing tape 200 was attached to the semiconductor wafer 7, the electrode pad 26 penetrated the adhesive layer 81 and its tip was located in the second layer 822. state can be Therefore, when grinding and polishing the back surface 72 of the semiconductor wafer 7 in the step [2A], it is possible to more accurately suppress or prevent the grinding water from entering the electrode pad 26, The thinning can be achieved in a state where the entire surface of the back surface 72 of the wafer 7 is thinned with a uniform thickness.

(5) Other components In addition to the above-described components (1) to (4), the resin composition constituting the adhesive layer 81 contains other components such as a tackifier, an anti-aging agent, and an adhesion adjuster. , fillers, colorants, flame retardants, softeners, antioxidants, plasticizers, surfactants, and the like.

Among these, the tackifier is not particularly limited. Resins and the like can be mentioned, and one or more of these can be used in combination.

Here, as described above, in the present invention, when the adhesive force of the adhesive layer 81 after irradiation with energy rays is F1 [N/25 mm] and the adhesive force of the second layer 822 is F2 [N/25 mm] , F1>F2 (F1-F2>0), the contamination of the electrode pads 26 caused by the adhesive layer 81 and the second layer 822 being caught on the electrode pads 26 can be suppressed or prevented. However, the adhesive force F1 [N/25 mm] of the adhesive layer 81 and the adhesive force F2 [N/25 mm] of the second layer 822 after irradiation with the energy beam are F1−F2>0.18. It is preferable that the relationship F1−F2≧0.27 be satisfied.

Further, the adhesive force F2 of the second layer 822 when satisfying this relationship is preferably 0.003 N/25 mm or less, more preferably less than 0.001 N/25 mm. As a result, the occurrence of contamination of the electrode pads 26 due to the second layer 822 being caught on the electrode pads 26 can be more accurately suppressed or prevented.

Furthermore, when the adhesive force of the adhesive layer 81 before irradiation of the energy beam is F1 _P [N/25 mm], the relational expression F1/ F1 _P is preferably 0.50 or less, more preferably 0.30 or less. As a result, the semiconductor wafer 7 can be reliably temporarily fixed to the temporary fixing tape 200 before the energy beam irradiation (especially, the step [1A]), and after the energy beam irradiation (the step [4A ]), the temporary fixing tape 200 can be peeled off from the semiconductor wafer 7 with higher accuracy.

The adhesive strength of the adhesive layer 81 and the adhesive strength of the second layer 822 before and after the energy beam irradiation are measured according to the adhesive strength measurement method of JIS Z 0237 (2009). be able to.

In addition, the laminated body with the second layer 822 including the adhesive layer 81 having such a configuration has a height of 200 μm, a width of 400 μm, and a pitch (interval) of 1.0 mm. The follow-up rate in the thickness direction is preferably 70% or more, more preferably 90% or more. If such a relationship is satisfied, the protrusions originating from the electrode pads 26 of different sizes formed on the semiconductor wafer 7 having various semiconductor elements 20 can also penetrate the adhesive layer 81 and adhere to the second adhesive layer 81 . The upper surface of the layer 822 can reliably follow the projection. Therefore, at the time of temporary fixing, it is possible to accurately suppress or prevent water from entering the projections provided on the semiconductor wafer 7, and the entire surface of the back surface 72 of the semiconductor wafer 7 is Since a more uniform pressing force can be applied, the grinding precision of the semiconductor wafer 7 can be further improved.

In the present invention, the follow-up rate of the adhesive layer 81 is determined by the semiconductor wafer 7 having a plurality of square pillar-shaped projections (ridges) with a height of 200 μm, a width of 400 μm, and a pitch (interval) of 1.0 mm on the surface 71 . is prepared, and when the temporary fixing tape 200 is attached to the surface 71 of the semiconductor wafer 7, the entire adhesive layer 81 (both the upper surface and the lower surface) follows the ridges on the temporary fixing tape 200. It is calculated by dividing the depth of the recess formed by the height of the protrusion.

In addition, the adhesive layer 81 preferably has a breaking elongation at 45° C. (according to ASTM-D-882) of 5% or more and 55% or less, and preferably 25% or more and 55% or less. It is more preferable to have As a result, in the step [1A], when the semiconductor wafer 7 is temporarily fixed to the temporary fixing tape 200, the adhesive is attached corresponding to the electrode pads 26 (protrusions) protruding from the surface 71 of the semiconductor wafer 7. The layer 81 is reliably broken, and the electrode pad 26 can be reliably penetrated through the adhesive layer 81 .

Furthermore, the elastic modulus of the adhesive layer 81 at 45° C. is preferably 0.01 MPa or more and 10 MPa or less, more preferably 0.03 MPa or more and 0.1 MPa or less. As a result, when the semiconductor wafer 7 is temporarily fixed to the temporary fixing tape 200 in the step [1A], the adhesive layer 81 broken by the electrode pad 26 is pierced by the electrode pad 26. , can be reliably tracked.

Further, when the thickness of the adhesive layer 81 is T1 [μm] and the height of the electrode pads 26 (protrusions) formed on the surface 71 of the semiconductor wafer 7 is H [μm], H−T1> It is preferable to satisfy the relationship 150, and it is more preferable to satisfy the relationship HT1≧190. As a result, the electrode pads 26 (protrusions) formed on the surface 71 of the semiconductor wafer 7 can reliably penetrate the adhesive layer 81, and the tip of the adhesive layer 81 can be applied to the second layer 822 with a high follow-up rate. As a result, the tip of the electrode pad 26 can be reliably positioned in the second layer 822 while the electrode pad 26 penetrates the adhesive layer 81 .

Furthermore, when the thickness of the adhesive layer 81 is T1 [μm] and the thickness of the second layer 822 is T2 [μm], it is preferable to satisfy the relationship T2−T1>400, and T2−T1≧ It is more preferable to satisfy the relationship 420. As a result, the tip of the electrode pad 26 can be more reliably positioned in the second layer 822 while penetrating the adhesive layer 81 with the electrode pad 26 .

Specifically, the thickness of the adhesive layer 81 is preferably 3 μm or more and less than 50 μm, and more preferably 5 μm or more and 15 μm or less. By setting the thickness of the adhesive layer 81 within this range, the electrode pads 26 (protrusions) formed on the surface 71 of the semiconductor wafer 7 can reliably penetrate the adhesive layer 81 . The tip of the electrode pad 26 can be reliably positioned in the second layer 822 while the pad 26 penetrates the adhesive layer 81 . Furthermore, the adhesive layer 81 exhibits good adhesive strength before applying energy to the adhesive layer 81, and after applying energy to the adhesive layer 81, between the adhesive layer 81 and the semiconductor wafer 7, Exhibits good releasability.

Note that the adhesive layer 81 may be composed of a laminate (multilayer body) in which a plurality of layers composed of different resin compositions are laminated.

Moreover, it is preferable that the temporary fixing tape 200 has a separator laminated on the adhesive layer 81 before being attached to the semiconductor wafer 7 . As a result, it is possible to reliably prevent dust or the like from adhering to the adhesive layer 81 unintentionally during storage, transportation, or the like of the temporary fixing tape 200 .

Furthermore, the separator is not particularly limited, but includes polypropylene film, polyethylene film, polyethylene terephthalate film, and the like.

Moreover, since the separator is peeled off when the tape 200 for temporary fixing is used, the separator may have a release treatment on the surface. Examples of the release treatment include a treatment of coating the separator surface with a release agent and a treatment of forming fine irregularities on the separator surface. Examples of release agents include silicone-based, alkyd-based, fluorine-based, and the like.

In the present embodiment, the semiconductor device 10 has the configuration shown in FIG. 1 described above, and the semiconductor device 10 is manufactured using the temporary fixing tape 200. However, the semiconductor device 10 is not limited to such a case. However, the temporary fixing tape 200 can be applied to the manufacture of various forms of semiconductor packages, such as dual in-line packages (DIP), chip carriers with plastic leads (PLCC), low-profile packages. Quad Flat Package (LQFP), Small Outline Package (SOP), Small Outline J-Lead Package (SOJ), Thin Small Outline Package (TSOP), Thin Quad Flat Package (TQFP), Tape Carrier Package (TCP), Ball Grid Array (BGA), Chip Size Package (CSP), Matrix Array Package Ball Grid Array (MAPBGA), Chip Stacked Chip Size Package It can be applied to memories such as packages and logic elements.

Although the temporary fixing tape of the present invention has been described above based on the illustrated embodiments, the present invention is not limited to this. can be replaced with any one capable of exhibiting the function of , or can be added with any configuration.

Next, specific examples of the present invention will be described.
It should be noted that the present invention is not limited to the description of these examples.

1. Investigation on Adhesiveness of Second Layer 1.1. Preparation of Raw Materials for Forming Adhesive Layer First, raw materials used for forming the adhesive layer in the production of the temporary fixing tapes of Examples and Comparative Examples are shown below.

(Acrylic copolymer A)
As the acrylic copolymer A, one containing a block copolymer composed of 90 parts by weight of butyl acrylate and 10 parts by weight of acrylic acid was prepared.
The weight average molecular weight of this acrylic copolymer A was 600,000.

(Energy beam polymerizable compound A)
As the energy ray-polymerizable compound A, a 15-functional oligomer urethane acrylate (manufactured by Miwon Specialty Chemical, product number: Miramer SC2152) was prepared.

(Crosslinking agent A)
As the cross-linking agent A, a trimethylolpropane condensation compound of toluenediisocyanate (manufactured by Tosoh Corporation, product number: Coronate L) was prepared.

(Energy beam polymerization initiator A)
As the energy ray polymerization initiator A, 2,2-dimethoxy-2-phenylacetophenone (manufactured by IGM, product number: OMNIRAD651) was prepared.

1.2. Preparation of Raw Materials for Forming the First Layer of the Supporting Substrate Next, in the production of the temporary fixing tapes of each of the examples and comparative examples, the raw materials for forming the first layer of the supporting substrate were prepared. The raw materials used are shown below.

(polypropylene)
A polypropylene (PP, manufactured by Sumitomo Chemical Co., Ltd., product number: FS2011DG3) was prepared.

1.3. Preparation of Raw Materials for Forming the Second Layer of the Supporting Substrate Next, in order to form the second layer of the supporting substrate during the production of the temporary fixing tapes of the respective examples and comparative examples, The raw materials used are shown below.

(Propylene/α-olefin copolymer)
A propylene/α-olefin copolymer (manufactured by Sumitomo Chemical Co., Ltd., product number: Tafselene H3712D) was prepared.

(Propylene/α-olefin copolymer)
A propylene/α-olefin copolymer (manufactured by Sumitomo Chemical Co., Ltd., product number: Tafselene H3714D) was prepared.

(Propylene/α-olefin copolymer)
A propylene/α-olefin copolymer (manufactured by Sumitomo Chemical Co., Ltd., product number: Tafselene H3002) was prepared.

(Hydrogenated styrene thermoplastic elastomer)
A hydrogenated styrene thermoplastic elastomer (manufactured by Asahi Kasei Corporation, product number: S1605) was prepared.

(polypropylene)
A polypropylene (PP, manufactured by Sumitomo Chemical Co., Ltd., product number: FS2011DG3) was prepared.

(Hydrogenated styrene thermoplastic elastomer)
A hydrogenated styrene thermoplastic elastomer (manufactured by Kuraray Co., Ltd., product number: Hybler 7125) was prepared.

(Polymer type antistatic agent)
A polymer-type antistatic agent (manufactured by Sanyo Chemical Industries, Ltd., product number: Plectron PVL) was prepared.

(Acrylic copolymer A)
As the acrylic copolymer A, one containing a block copolymer composed of 90 parts by weight of butyl acrylate and 10 parts by weight of acrylic acid was prepared.
The weight average molecular weight of this acrylic copolymer A was 600,000.

(Crosslinking agent A)
As the cross-linking agent A, a trimethylolpropane condensation compound of toluenediisocyanate (manufactured by Tosoh Corporation, product number: Coronate L) was prepared.

1.4. Preparation of temporary fixing tape [Example 1A]
[1A] First, polypropylene as a material for forming the first layer and a propylene/α-olefin copolymer (Tafselene H3712D) as a material for forming the second layer were placed in two extruders.

[2A] Next, by extruding these in a molten state from two extruders, a molten laminate in which these are laminated in layers is obtained from a co-extrusion T die. was cooled to obtain the supporting base material 82 . The thickness of the first layer 821 in the supporting base material 82 was 50.0 μm, and the thickness of the second layer 822 was 430.0 μm.

[3A] Next, acrylic copolymer A (52.2 wt%), energy ray polymerizable compound A (31.3 wt%), cross-linking agent A (13.0 wt%) and energy ray polymerization initiator A (3 .5 wt %) was prepared.

After this liquid material was die-coated on a release PET film, an adhesive layer 81 was formed on the upper surface (one surface) of the release PET film at a transport speed for drying at 80° C. for 1 minute. Incidentally, the thickness of the adhesive layer 81 was 10.0 μm.

After that, the adhesive layer 81 on the release PET film is laminated so as to be in contact with the second layer 822 of the supporting substrate 82, and the temporary fixing of Example 1A in which the adhesive layer 81 is formed on the upper surface of the supporting substrate 82. A tape for

[Example 2A]
A temporary fixing tape was prepared in the same manner as in Example 1A except that a hydrogenated styrene thermoplastic elastomer (S1605) was used as the material for forming the second layer.

[Example 3A]
Except for using a kneaded mixture of a hydrogenated styrene-based thermoplastic elastomer (S1605; 85.0 wt%) and a polymeric antistatic agent (Pelectron PVL; 15.0 wt%) as the material for forming the second layer, A temporary fixing tape was produced in the same manner as in Example 1A.

[Example 4A]
Example 1A except that a kneaded product of hydrogenated styrene thermoplastic elastomer (Hibler 7125; 80.0 wt%) and polypropylene (PP; 20.0 wt%) was used as the material for forming the second layer. A temporary fixing tape was produced in the same manner.

[Example 5A]
Example 1A except that a kneaded product of hydrogenated styrene thermoplastic elastomer (Hibler 7125; 70.0 wt%) and polypropylene (PP; 30.0 wt%) was used as the material for forming the second layer. A temporary fixing tape was produced in the same manner.

[Example 6A]
A temporary fixing tape was prepared in the same manner as in Example 1A except that a propylene/α-olefin copolymer (Tafselene H3714D) was used as the material for forming the second layer.

[Example 7A]
A temporary fixing tape was prepared in the same manner as in Example 1A except that a propylene/α-olefin copolymer (Tafselene H3002) was used as the material for forming the second layer.

[Comparative Example 1A]
Example 1A except that a resin composition containing an acrylic copolymer A (90.1 wt%) and a cross-linking agent A (9.9 wt%) was used as the material for forming the second layer. A temporary fixing tape was produced in the same manner.

1.5. Evaluation of temporary fixing tape 1.5.1 Evaluation of adhesive strength of adhesive layer before irradiation of energy beam An adhesive layer 81 was formed using raw materials. Next, the adhesive strength of the adhesive layer 81 before irradiation with energy rays was measured using a desk-top precision universal testing machine AUTOGRAPH (manufactured by SHIMADZU, "AGS- X").

1.5.2 Evaluation of the adhesive strength of the adhesive layer after irradiation with energy rays The adhesive layer was prepared using the raw material for forming the adhesive layer, which was prepared when the temporary fixing tapes of each example and comparative example were produced. 81 was formed. Next, the adhesive layer 81 was irradiated with ultraviolet rays as energy rays at an illuminance of 25 mW and an integrated light quantity of 500 mJ/cm ² , and the adhesive strength was measured according to the adhesive strength measurement method of JIS Z 0237 (2009). Then, it was measured using a desktop precision universal testing machine AUTOGRAPH (manufactured by SHIMADZU, "AGS-X").

1.5.3 Evaluation of Adhesive Strength of Second Layer 822 was formed. Next, the adhesive force of this second layer 822 was measured using a desktop precision universal testing machine AUTOGRAPH (manufactured by SHIMADZU, "AGS-X") in accordance with the adhesive force measurement method of JIS Z 0237 (2009). was measured using

1.5.4 Evaluation of Embedability of Temporary Fixing Tape On the surface of the transparent glass substrate, the temporary fixing tapes obtained in Examples 1A to 7A and Comparative Example 1A were peeled off the release PET film, and then the stage was heated to 45 ° C., with a diameter of 35 mm and 400 mm. It was pasted by pressing a wide roller with a pressure of 0.5 MPa.

Then, in the temporary fixing tape, while penetrating the adhesive layer, the depth of the recess formed so that the upper surface of the second layer follows the protrusion is divided by the height of the protrusion. was calculated, and the embedding property of the projections in the temporary fixing tape 200 was evaluated based on the following evaluation criteria based on the obtained follow-up rate.

<Evaluation Criteria for Embedability of Temporary Fixing Tape>
◎: While penetrating the adhesive layer, the upper surface of the second layer follows the protrusion,
In addition, the temporary fixing tape has a conformability of 90% or more to projections.
○: The upper surface of the second layer follows the protrusion while penetrating the adhesive layer,
In addition, the follow-up rate of the temporary fixing tape to the projection is 70% or more and less than 90%.
×: The adhesive layer does not penetrate,
Furthermore, the follow-up rate of the temporary fixing tape to the projection is less than 70%.
Table 1 shows the evaluation results.

1.5.5 Evaluation of the presence or absence of thickness unevenness in semiconductor wafers Hemispherical projections (convex portions) with a height of 200 µm, a width of 400 µm, and a pitch of 1.0 mm are provided in a grid pattern vertically and horizontally. ) is prepared on the surface 71 of the semiconductor wafer 7 having a diameter of 300 mm. After peeling off, while the stage was heated to 45° C., a roller with a diameter of 35 mm and a width of 400 mm was pressed under conditions of a pressure of 0.5 MPa to adhere.

After that, the back surface 72 of the semiconductor wafer 7 was polished to a thickness of 50 μm using a polishing machine (manufactured by Disco, "product name: DAG810").

Then, the semiconductor wafer 7 after polishing is measured using a high-precision thickness and shape measuring device (manufactured by Kozu Seiki Co., Ltd., "Model number DY-3000") at equal intervals so as to form a lattice shape vertically and horizontally. The thickness was measured at 10,000 points. Then, by calculating the difference between the maximum and minimum values of the thickness measured at 10,000 locations, the magnitude of thickness unevenness in the semiconductor wafer 7 was obtained.

<Evaluation Criteria for Presence or Absence of Thickness Unevenness in Semiconductor Wafers>
A: The magnitude of thickness unevenness in the semiconductor wafer 7 is 5 μm or less.
◯: The size of the thickness unevenness in the semiconductor wafer 7 is more than 5 μm and less than 10 μm.
x: The size of thickness unevenness in the semiconductor wafer 7 is 10 μm or more.
Table 1 shows the evaluation results.

1.5.6 Evaluation of the presence or absence of peelability of the temporary fixing tape Hemispherical projections (convex portions ) is prepared on the surface 71 of the semiconductor wafer 7 having a diameter of 300 mm. After peeling, the film was attached by pressing a roller with a diameter of 35 mm and a width of 400 mm at a pressure of 0.5 MPa while the stage was heated to 45° C., and then allowed to stand still for 1 hour.

After that, the adhesive layer 81 was irradiated with ultraviolet rays as energy rays at an illuminance of 70 mW and an integrated amount of light of 600 mJ/cm ² , and then the temporary fixing tape 200 was peeled off from the semiconductor wafer 7 . Then, the presence or absence of contamination on the projections (convex portions) provided on the semiconductor wafer 7 from which the temporary fixing tape 200 was peeled off was observed, and evaluated based on the following evaluation criteria.

<Evaluation Criteria for Peelability of Temporary Fixing Tape>
◎: In the protrusion provided on the semiconductor wafer 7,
No contamination originating from the adhesive layer or the second layer is observed.
◯: Slight contamination originating from the adhesive layer or the second layer is observed in the protrusions of the semiconductor wafer 7, but the conductive properties of the protrusions are not affected.
Δ: Contamination originating from the adhesive layer or the second layer is observed in the protrusions of the semiconductor wafer 7, and the conductive properties of the protrusions are slightly affected.
x: Clear contamination derived from the adhesive layer or the second layer is observed in the projections provided on the semiconductor wafer 7, and the conductive properties of the projections are clearly affected.
Table 1 shows the evaluation results.

As is clear from Table 1, in each example, the follow-up rate of the temporary fixing tape to the projections is 70% or more, and the tip of the projection penetrates the adhesive layer while the second layer The adhesive tape covers the semiconductor wafer 7 with the upper surface of the tape following the protrusion. As a result, the thickness unevenness of the semiconductor wafer is reduced, and the semiconductor wafer 7 can be ground with excellent grinding accuracy.

Furthermore, in each embodiment, the relationship F1>F2 is satisfied while covering the semiconductor wafer 7 in the above state, so that the contamination originating from the adhesive layer or the second layer is prevented from forming projections. However, the results showed that the adhesive tape could be peeled off from the semiconductor wafer with excellent peelability.

On the other hand, in the comparative example, as in each example, the follow-up rate of the temporary fixing tape to the projection was 70% or more, and the tip of the projection penetrated the adhesive layer, Since the adhesive tape covers the semiconductor wafer 7 in a state where the upper surface of the layer 2 follows the protrusion, the size of thickness unevenness in the semiconductor wafer can be reduced, and the semiconductor wafer 7 can be A result that can be ground with excellent grinding accuracy was obtained. However, the relationship of F1>F2 is not satisfied, contamination derived from the adhesive layer or the second layer is clearly observed in the protrusions, and the adhesive tape cannot be peeled off from the semiconductor wafer with excellent peelability. could not.

2. Examination on Penetrability of Adhesive Layer 2.1. Preparation of Raw Materials for Forming Adhesive Layer First, the raw materials used for forming the adhesive layer in the production of the temporary fixing tapes of each example and each comparative example are shown below.

(Acrylic copolymer A)
As the acrylic copolymer A, one containing a block copolymer composed of 90 parts by weight of butyl acrylate and 10 parts by weight of acrylic acid was prepared.
The weight average molecular weight of this acrylic copolymer A was 600,000.

(Energy beam polymerizable compound A)
As the energy ray-polymerizable compound A, a 15-functional oligomer urethane acrylate (manufactured by Miwon Specialty Chemical, product number: Miramer SC2152) was prepared.

(Crosslinking agent A)
As the cross-linking agent A, a trimethylolpropane condensation compound of toluenediisocyanate (manufactured by Tosoh Corporation, product number: Coronate L) was prepared.

(Energy beam polymerization initiator A)
As the energy ray polymerization initiator A, 2,2-dimethoxy-2-phenylacetophenone (manufactured by IGM, product number: OMNIRAD651) was prepared.

2.2. Preparation of Raw Materials for Forming the First Layer of the Supporting Substrate Next, in the production of the temporary fixing tapes of each example and each comparative example, for forming the first layer of the supporting substrate, The raw materials used for are shown below.

(polypropylene)
A polypropylene (PP, manufactured by Sumitomo Chemical Co., Ltd., product number: FS2011DG3) was prepared.

2.3. Preparation of Raw Materials for Forming the Second Layer of the Supporting Substrate Next, in order to form the second layer of the supporting substrate during the production of the temporary fixing tapes of each example and each comparative example, The raw materials used for are shown below.

(Propylene/α-olefin copolymer)
A propylene/α-olefin copolymer (manufactured by Sumitomo Chemical Co., Ltd., product number: Tafselene H3712D) was prepared.

2.4. Preparation of temporary fixing tape [Example 1B]
[1B] First, polypropylene as a material for forming the first layer and a propylene/α-olefin copolymer (Tafselene H3712D) as a material for forming the second layer were each placed in two extruders.

[2B] Next, by extruding these in a molten state from two extruders, a molten laminate in which these are laminated in layers is obtained from a co-extrusion T die. was cooled to obtain the supporting base material 82 . The thickness of the first layer 821 in the supporting base material 82 was 50.0 μm, and the thickness of the second layer 822 was 430.0 μm.

[3B] Next, acrylic copolymer A (52.2 wt%), energy ray polymerizable compound A (31.3 wt%), cross-linking agent A (13.0 wt%) and energy ray polymerization initiator A (3 .5 wt %) was prepared.

After this liquid material was die-coated on a release PET film, an adhesive layer 81 was formed on the upper surface (one surface) of the release PET film at a conveying speed of drying at 80° C. for 1 minute. Incidentally, the thickness of the adhesive layer 81 was 10.0 μm.

After that, the adhesive layer 81 on the release PET film is laminated so as to be in contact with the second layer 822 of the supporting substrate 82, and the adhesive layer 81 is formed on the upper surface of the supporting substrate 82 Temporary fixing of Example 1B A tape for

[Example 2B]
As a liquid material for forming the adhesive layer 81, an acrylic copolymer A (43.6 wt%), an energy ray polymerizable compound A (37.7 wt%), a cross-linking agent A (16.4 wt%) and an energy ray A temporary fixing tape was produced in the same manner as in Example 1B except that a resin composition containing a polymerization initiator A (2.3 wt %) was used.

[Example 3B]
As a liquid material for forming the adhesive layer 81, an acrylic copolymer A (35.2 wt%), an energy ray polymerizable compound A (49.3 wt%), a cross-linking agent A (13.2 wt%) and an energy ray A temporary fixing tape was produced in the same manner as in Example 1B except that a resin composition containing a polymerization initiator A (2.3 wt %) was used.

[Example 4B]
As a liquid material for forming the adhesive layer 81, an acrylic copolymer A (40.3 wt%), an energy ray polymerizable compound A (56.5 wt%), a cross-linking agent A (0.5 wt%) and an energy ray A temporary fixing tape was produced in the same manner as in Example 1B except that a resin composition containing a polymerization initiator A (2.7 wt %) was used.

[Comparative Example 1B]
A temporary fixing tape was produced in the same manner as in Example 1B except that the thickness of the adhesive layer 81 to be formed was 50.0 μm.

[Comparative Example 2B]
A temporary fixing tape was produced in the same manner as in Example 1B except that the thickness of the adhesive layer 81 to be formed was 100.0 μm.

2.5. Evaluation of temporary fixing tape 2.5.1 Evaluation of elastic modulus of second layer Raw materials for forming the second layer prepared when producing the temporary fixing tape of each example and each comparative example was used to form the second layer 822 . Next, the elastic modulus of the second layer 822 at 25° C. and 45° C. was measured using a viscoelasticity measuring device (manufactured by Seiko Instruments Inc., model number DMS6100).

2.5.2 Evaluation of Elastic Modulus of Adhesive Layer An adhesive layer 81 was formed using the raw material for forming the adhesive layer, which was prepared when the temporary fixing tapes of each example and each comparative example were produced. Next, the elastic modulus of the adhesive layer 81 at 45° C. was measured using a viscoelasticity measuring device (manufactured by Seiko Instruments Inc., model number DMS6100).

2.5.3 Evaluation of Breaking Elongation of Adhesive Layer Adhesive layer 81 was formed using the raw material for forming the adhesive layer prepared when producing the temporary fixing tapes of each example and each comparative example. . Next, the elongation at break of the adhesive layer 81 at 45° C. was measured using a desk-top precision universal testing machine AUTOGRAPH (manufactured by SHIMADZU, "AGS-X").

2.5.4 Evaluation of Embedability of Temporary Fixing Tape On the surface of the transparent glass substrate, the temporary fixing tapes obtained in Examples 1B to 4B and Comparative Examples 1B and 2B were peeled off the release PET film, and then the stage was heated to 45 ° C., with a diameter of 35 mm. , and a 400 mm wide roller at a pressure of 0.5 MPa.

Then, in the temporary fixing tape, while penetrating the adhesive layer, the depth of the recess formed so that the upper surface of the second layer follows the protrusion is divided by the height of the protrusion. was calculated, and the obtained follow-up rate was used to evaluate the embeddability of the protrusions in the temporary fixing tape based on the following evaluation criteria.

<Evaluation Criteria for Embedability of Temporary Fixing Tape>
◎: While penetrating the adhesive layer, the upper surface of the second layer follows the protrusion,
In addition, the temporary fixing tape has a conformability of 90% or more to projections.
○: The upper surface of the second layer follows the protrusion while penetrating the adhesive layer,
In addition, the follow-up rate of the temporary fixing tape to the projection is 70% or more and less than 90%.
×: The adhesive layer does not penetrate,
Furthermore, the follow-up rate of the temporary fixing tape to the projection is less than 70%.
Table 2 shows the evaluation results.

2.5.5 Evaluation of presence or absence of thickness unevenness in semiconductor wafers Hemispherical projections (convex portions) with a height of 200 μm, a width of 400 μm, and a pitch of 1.0 mm are arranged in a lattice pattern vertically and horizontally. ) is prepared on the surface 71 of the semiconductor wafer 7 having a diameter of 300 mm. After peeling off, while the stage was heated to 45° C., a roller with a diameter of 35 mm and a width of 400 mm was pressed under conditions of a pressure of 0.5 MPa to adhere.

After that, the back surface 72 of the semiconductor wafer 7 was polished to a thickness of 50 μm using a polishing machine (manufactured by Disco, "product name: DAG810").

Then, the semiconductor wafer 7 after polishing is measured using a high-precision thickness and shape measuring device (manufactured by Kozu Seiki Co., Ltd., "Model number DY-3000") at equal intervals so as to form a lattice shape vertically and horizontally. The thickness was measured at 10,000 points. Then, by calculating the difference between the maximum and minimum values of the thickness measured at 10,000 locations, the magnitude of thickness unevenness in the semiconductor wafer 7 was obtained.

<Evaluation Criteria for Presence or Absence of Thickness Unevenness in Semiconductor Wafers>
A: The magnitude of thickness unevenness in the semiconductor wafer 7 is 5 μm or less.
◯: The size of the thickness unevenness in the semiconductor wafer 7 is more than 5 μm and less than 10 μm.
x: The size of thickness unevenness in the semiconductor wafer 7 is 10 μm or more.
Table 2 shows the evaluation results.

As is clear from Table 2, in each example, the follow-up rate of the temporary fixing tape to the projections was 70% or more, and the tips of the projections penetrated the adhesive layer while forming the second layer. The adhesive tape covers the semiconductor wafer 7 with the upper surface of the tape following the protrusion. As a result, the thickness unevenness of the semiconductor wafer is reduced, and the semiconductor wafer 7 can be ground with excellent grinding accuracy.

On the other hand, in each comparative example, the tip of the protrusion does not penetrate the adhesive layer due to the thickness T1 of the adhesive layer being set thick, and the protrusion of the temporary fixing tape Since the adhesive tape covers the semiconductor wafer 7 in a state where the follow-up rate to the object is less than 70%, the size of the thickness unevenness in the semiconductor wafer cannot be reduced. 7 could not be ground with excellent grinding accuracy.

2 adhesive layer 4 substrate 7 wafer for semiconductor 9 wafer ring 10 semiconductor device 20 semiconductor element 21 bump 22 covering portion 23 wiring 25 interposer 26 electrode pad 27 sealing portion 71 front surface 72 back surface 81 adhesive layer 82 supporting substrate 100 for semiconductor Adhesive Tape for Wafer Processing 121 Peripheral Part 122 Center Part 200 Temporary Fixing Tape 221 Opening 251 Opening 821 First Layer 822 Second Layer

Claims (7)

A supporting substrate and an adhesive layer laminated on one surface of the supporting substrate,
In order to process the substrate, the substrate is temporarily fixed to the supporting base via the adhesive layer, and after processing the substrate, the adhesive layer is irradiated with an energy beam to separate the substrate from the supporting base. Temporary fixing tape used for fixing,
The supporting substrate has a first layer that supports the substrate, and a second layer that is located between the first layer and the adhesive layer and has cushioning properties,
When the substrate having projections on at least one surface is bonded to the adhesive layer, the tips of the projections penetrate the adhesive layer and are located in the second layer,
When the adhesive force of the adhesive layer after irradiation with the energy beam is F1 [N/25 mm] and the adhesive force of the second layer is F2 [N/25 mm], satisfying the relationship F1>F2 ,
The temporary fixing tape , wherein the adhesive force F2 of the second layer is less than 0.003 N/25 mm . The temporary fixing tape according to claim 1 , wherein the second layer has an elastic modulus M2 at 45°C of 1 MPa or more and 50 MPa or less. The temporary fixing tape according to claim 1 or 2 , wherein the adhesive layer has a breaking elongation G1 of 5% or more and 55% or less at 45°C before irradiation with the energy beam. The adhesive layer contains an acrylic copolymer, a cross-linking agent, an energy ray-polymerizable compound that polymerizes when irradiated with energy rays, and an energy ray polymerization initiator,
4. The temporary fixing tape according to any one of claims 1 to 3 , which has adhesiveness before irradiation with said energy rays, and said adhesiveness is reduced by said irradiation with said energy rays. The temporary fixing tape according to any one of claims 1 to 4 , wherein the second layer contains a thermoplastic elastomer as a main material. The temporary fixing tape according to any one of claims 1 to 5 , wherein the substrate is a semiconductor wafer, and the protrusions are bumps provided on the semiconductor wafer. 7. The temporary fixing tape according to claim 6 , wherein said processing is semiconductor wafer grinding for grinding the other surface of said semiconductor wafer to reduce the thickness of said semiconductor wafer.

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