JP6623639B2 - Temporary fixing tape - Google Patents

Description

  The present invention relates to a temporary fixing tape.

  In recent years, demands for higher density and higher integration of semiconductor devices have been increasing in response to the increasing functionality of electronic devices and expansion to mobile applications, and IC packages have been reduced in size and increased in capacity and density.

  As a method of manufacturing these semiconductor devices, a semiconductor wafer in which a plurality of semiconductor elements are formed is cut and separated (separated) into a plurality of semiconductor elements by dicing, and then the obtained semiconductor elements are separated. After bonding to a metal lead frame or a substrate, the semiconductor device is further sealed with a mold resin to manufacture a semiconductor device.

  Here, for the purpose of realizing the miniaturization of the semiconductor element and hence the semiconductor device and the IC package, the semiconductor obtained by grinding and polishing the back surface opposite to the surface on which the semiconductor elements are formed of the semiconductor wafer is obtained. Elements are being made thinner.

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

  In this method, the thickness of the semiconductor wafer is reduced by grinding and polishing the semiconductor wafer. In addition, a temporary fixing tape is attached to the surface on which the semiconductor elements are formed, and even if the thickness of the semiconductor wafer is reduced by the grinding and polishing, warpage of the semiconductor wafer is generated. It must be prevented.

  However, with the temporary fixing tape described in Patent Document 1 or the like, the semiconductor wafer is warped as the thickness of the semiconductor wafer is reduced, and further, depending on the degree of the warp, the semiconductor wafer is cracked. In addition, there is a problem that the yield of the manufactured semiconductor device is reduced.

  Such a problem is not limited to the semiconductor wafer, but similarly occurs for various substrates that are processed while being fixed to the temporary fixing tape.

WO 2009/28068

  An object of the present invention is to provide a temporary fixing tape that can fix a substrate without warping the substrate even if the thickness is reduced by grinding and polishing the substrate.

Such an object is achieved by the present invention described in the following (1) to (7).
(1) comprising a support base material and an adhesive layer laminated on one surface of the support base material;
The substrate is temporarily fixed to the support base via the adhesive layer for processing the substrate, and the substrate is detached from the support base by irradiating the adhesive layer with energy rays after processing the substrate. It is a temporary fixing tape used for causing
The substrate includes a plurality of recesses on a protection surface located on a side opposite to a processing surface on which the processing is performed,
When the supporting base material is applied with an elongating force to extend the supporting base material in one direction to the supporting base material and elongates the supporting base material by 10% in the one direction, the elongating force is released, and thereafter, when 10 minutes have elapsed. The shrinkage load is 0.8 MPa or less, and the supporting base material has a minimum value of tanδ of dynamic viscoelasticity in a temperature range of 20 ° C. or more and 60 ° C. or less of 0.4 or more ,
The adhesive layer has a shear adhesive force of 0.8 MPa or more under a temperature condition of 23 ° C. before irradiation of the adhesive layer with energy rays, and the adhesive layer has a thickness of at least 30% before irradiation of the adhesive layer with energy rays. 3. The temporary fixing tape according to claim 1, wherein a follow-up rate of the concave portion having a depth of 0.03 mm and a width of 0.3 mm is 80% or more and 100% or less .

( 2 ) The temporary fixing tape according to (1) , wherein the support base material contains a thermoplastic elastomer as a main material.

( 3 ) The temporary fixing tape according to the above ( 2 ), wherein the thermoplastic elastomer contains a styrene-based elastomer.

( 4 ) The styrene elastomer is at least one of a partially hydrogenated styrene-butadiene-styrene copolymer, a completely hydrogenated styrene-butadiene-styrene copolymer, and a styrene-isobutylene-styrene copolymer. The temporary fixing tape according to ( 3 ), which is a seed.

( 5 ) The pressure-sensitive adhesive layer according to any one of the above (1) to ( 4 ), wherein the adhesive layer contains an acrylic copolymer, a crosslinking agent, an energy ray-polymerizable compound polymerized by irradiation with energy rays, and an energy ray polymerization initiator. Temporary fixing tape as described.

(6) The substrate, the temporary fixing tape according to any one of (1) to a semiconductor wafer (5).

(7) the processing, the temporary fixing tape according to the above (6) is a semiconductor wafer grinding by grinding the working surface of the semiconductor wafer to reduce the thickness of the semiconductor wafer.

  ADVANTAGE OF THE INVENTION According to the temporary fixing tape of this invention, even if the thickness becomes thin by grinding and grinding | polishing of a board | substrate, a board | substrate can be fixed in the state which suppressed generation | occurrence | production of the warpage in a board | substrate exactly.

It is a longitudinal section showing an example of the semiconductor device manufactured using the temporary fixing tape of the present invention. FIG. 2 is a longitudinal sectional view for explaining a method of manufacturing the semiconductor device shown in FIG. 1 using the temporary fixing tape of the present invention. FIG. 2 is a longitudinal sectional view for explaining a method of manufacturing the semiconductor device shown in FIG. 1 using the temporary fixing tape of the present invention. It is a longitudinal section showing an embodiment of the temporary fixing tape of the present invention.

Hereinafter, the temporary fixing tape of the present invention will be described in detail.
First, prior to describing the temporary fixing tape of the present invention, a semiconductor device manufactured using the temporary fixing tape of the present invention will be described.
<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 referred to as “upper”, and the lower side is referred to as “lower”.

  The semiconductor device 10 shown in FIG. 1 is a QFP (Quad Flat Package) type semiconductor package, and includes a semiconductor chip (semiconductor element) 20, a die pad 30 supporting the semiconductor chip 20 via an adhesive layer 60, and a semiconductor chip 20. And a mold portion (sealing portion) 50 for sealing the semiconductor chip 20.

  The die pad 30 is made of a metal substrate and has a function as a support for supporting the semiconductor chip 20.

  The die pad 30 is made of, for example, a metal substrate made of various metal materials such as Cu, Fe, Ni, or an alloy thereof (for example, a Cu-based alloy or an iron / nickel-based alloy such as Fe-42Ni). The surface of the metal substrate is provided with silver plating or Ni-Pd plating, and the surface of Ni-Pd plating is further provided with a gold plating (gold flash) layer provided for improving the stability of the Pd layer. Are used.

  The shape of the die pad 30 in plan view generally corresponds to the shape of the semiconductor chip 20 in plan view, and is, for example, a square such as a square or a rectangle.

A plurality of leads 40 are radially provided on an outer peripheral portion of the die pad 30.
The end of the lead 40 opposite to the die pad 30 protrudes (exposes) from the mold part 50.

  The lead 40 is made of a conductive material. For example, the same material as that of the die pad 30 described above can be used.

  Further, the lead 40 may be provided with tin plating or the like on its surface. Accordingly, when the semiconductor device 10 is connected to the terminals of the motherboard via the solder, the adhesion between the solder and the leads 40 can be improved.

  The semiconductor chip 20 is fixed (fixed) to the die pad 30 via an adhesive layer 60.

  The adhesive layer 60 is not particularly limited, and is formed using various adhesives such as an epoxy adhesive, an acrylic adhesive, a polyimide adhesive, and a cyanate adhesive. Further, the adhesive layer 60 may include metal particles such as silver powder and copper powder. Thereby, the heat conductivity of the adhesive layer 60 is improved, so that heat is efficiently transmitted from the semiconductor chip 20 to the die pad 30 via the adhesive layer 60, so that the heat dissipation during driving of the semiconductor chip 20 is improved. .

  The semiconductor chip 20 has an electrode pad 21, and the electrode pad 21 and the lead 40 are electrically connected by a wire 22. Thus, the semiconductor chip 20 and each lead 40 are electrically connected.

  The material of the wire 22 is not particularly limited, but the wire 22 can be composed of, for example, an Au wire or an Al wire.

  The die pad 30, the members provided on the upper surface side of the die pad 30, and the part inside the lead 40 are sealed by the mold part 50. As a result, the outer ends of the leads 40 protrude from the mold part 50 made of a cured product of the semiconductor sealing material.

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

<Semiconductor device manufacturing method>
2 and 3 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 and 3 is referred to as “upper”, and the lower side is referred to as “lower”.

[1A] First, a temporary fixing having a semiconductor wafer 7 on which a plurality of semiconductor chips 20 are formed, a support base material 82, and an adhesive layer 81 laminated on the upper surface (one surface) of the support base material 82 Is prepared, and the temporary fixing tape 200 is pressed on the surface (protective surface) 71 of the semiconductor wafer 7 with the adhesive layer 81 of the temporary fixing tape 200 facing the front surface 71 side, thereby stacking ( (See FIG. 2A).
That is, the semiconductor wafer 7 is temporarily fixed to the temporary fixing tape 200.

  The plurality of semiconductor chips 20 are formed on the surface 71 of the semiconductor wafer 7, and as a result, the semiconductor wafer 7 has a plurality of recesses on the surface 71.

[2A] Next, the back surface (processed surface) 72 opposite to the front surface 71 of the semiconductor wafer 7 is ground or polished (back-ground) with the temporary fixing tape 200 adhered to the front surface 71 side ( FIG. 2 (c)).

  The grinding / polishing of the back surface 72 of the semiconductor wafer 7 can be performed using, for example, a grinding device (grinder) as shown in FIG.

  By the grinding and polishing of the back surface 72, the thickness of the semiconductor wafer 7 varies depending on the electronic device to which the semiconductor device 10 is applied, but 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. Set to about. As a result, the thickness of the obtained semiconductor chip 20 is reduced, and the size of the semiconductor device including the semiconductor chip 20 and the size of the IC package can be reduced.

  Although the semiconductor wafer 7 is preferably ground and polished to such a small thickness, even if the semiconductor wafer 7 is ground and polished to such a small thickness, by using the temporary fixing tape 200 of the present invention, The semiconductor wafer 7 can be fixed by the temporary fixing tape 200 in a state where the occurrence of the warpage in the semiconductor wafer 7 is accurately suppressed or prevented, but the detailed description will be given later.

[3A] Next, a semiconductor wafer processing adhesive tape 100 (hereinafter, sometimes simply referred to as “adhesive tape 100”) having a substrate 4 and an adhesive layer 2 laminated on the upper surface of the substrate 4. 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 placed at the center 122 thereof. The semiconductor wafer 7 is stacked (attached) by placing it on the top and pressing lightly (see FIG. 2D).

  Note that the semiconductor wafer 7 may be placed on a dicer table after the semiconductor wafer 7 is pasted on the adhesive tape 100 in advance.

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

  Examples of the energy ray include a particle beam such as an ultraviolet ray, an electron beam, and an ion beam, or a combination of two or more of these energy rays. Among these, it is particularly preferable to use ultraviolet rays. According to the ultraviolet rays, the adhesiveness of the adhesive layer 81 to the semiconductor wafer 7 can be efficiently reduced.

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

  Further, the cutting of the semiconductor wafer 7 using the blade is performed so that the semiconductor wafer 7 reaches halfway in the thickness direction of the base material 4 as shown in FIG. Thus, the semiconductor wafer 7 can be reliably separated.

[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 wafer 7 is reduced.
As a result, a state occurs in which separation occurs between the adhesive layer 2 and the semiconductor wafer 7.

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

  Examples of the energy ray include those similar to those described in the step [4A].

[7A] Next, the adhesive tape 100 is radially stretched by an expander (not shown) to open the singulated semiconductor wafers 7 (semiconductor chips 20) at regular intervals (see FIG. 3B). The semiconductor chip 20 is pushed up using a needle or the like, and in this state, is picked up by suction using a vacuum collet or air tweezers (see FIG. 3C).

[8A] Next, the picked-up semiconductor chip 20 is mounted on the die pad 30 via the adhesive layer 60, and then the electrode pad 21 included in the semiconductor chip 20 and the lead 40 are wire-bonded to each other, so that the wires 22 are electrically connected. Connection.

[9A] Next, the semiconductor chip 20 is sealed with the mold part 50.
The sealing by the mold part 50 is performed, for example, by preparing a molding die having an internal space corresponding to the shape of the mold part 50 to be formed, and forming a powder form so as to surround the semiconductor chip 20 disposed in the internal space. Is filled in the internal space. Then, in this state, the semiconductor encapsulating material is cured by heating to form a cured product of the semiconductor encapsulating material.

  The semiconductor device 10 is obtained by the method of manufacturing a semiconductor device having the above-described steps. More specifically, after the steps [1A] to [9A] are performed, the steps [7A] to [9A] are repeatedly performed, whereby a plurality of semiconductor devices 10 are collectively collected from one semiconductor wafer 7. Can be manufactured.

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

<Temporary fixing tape>
FIG. 4 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. 4 is referred to as “upper”, and the lower side is referred to as “lower”.

  As shown in FIG. 4, the temporary fixing tape 200 includes a support substrate 82 and an adhesive layer 81 laminated on the upper surface (one surface) of the support substrate 82, and processes the semiconductor wafer 7. For this purpose, the semiconductor wafer 7 is temporarily fixed to the support base material 82 via the adhesive layer 81 and the semiconductor wafer 7 is processed by irradiating the adhesive layer 81 with energy rays after processing the semiconductor wafer 7. The support base 82 is applied after the support base 82 is extended by 10% in one direction by applying an extension force to the support base 82 to extend the support base 82 in one direction. The contraction load when 10 minutes have passed after the extension force was released is 0.8 MPa or less.

  Since the contraction load is 0.8 MPa or less, the temporary fixing tape 200 is attached to the semiconductor wafer 7 at the time of temporary fixing, that is, at the step [1A], and thereafter, at the step [2A] In the above, even if the thickness of the semiconductor wafer 7 is reduced by grinding and polishing, the occurrence of warpage in the semiconductor wafer 7 can be accurately suppressed or prevented. Accordingly, the occurrence of cracks in the semiconductor wafer 7 due to the warpage of the semiconductor wafer is also accurately suppressed or prevented, and the yield of the manufactured semiconductor devices 10 is improved.

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

<Supporting base material 82>
The support base material 82 has a function of supporting the adhesive layer 81 provided on the support base material 82 and the semiconductor wafer 7 attached to the adhesive layer 81.

  Here, as described in the background art, when the semiconductor wafer is ground and polished with the temporary fixing tape attached to the semiconductor wafer to reduce its thickness, warpage occurs in the semiconductor wafer. There was a problem.

  According to the study of the present inventors, it has been found that such a problem mainly arises from the following.

  That is, in the step [1A], it is required that the temporary fixing tape be attached to the semiconductor wafer without causing bubbles and wrinkles in the temporary fixing tape. For this reason, in attaching the temporary fixing tape to the semiconductor wafer, the temporary fixing tape is attached in advance after the temporary fixing tape is extended by applying an elongating force for extending the temporary fixing tape in at least one direction to the temporary fixing tape. This prevents the occurrence of bubbles and wrinkles.

  However, since the temporary fixing tape is stuck by such a method, a contraction force remains on the temporary fixing tape, and further, the thickness of the semiconductor wafer is reduced in the step [2A]. It was considered that the semiconductor wafer after the grinding and polishing was warped.

  Further, the present inventor has further examined that, among the adhesive layer and the supporting base material provided in the temporary fixing tape, the shrinking force is generated by the supporting base material being dominant. Therefore, defining the contraction force of the support base material 82, that is, applying the elongation force for extending the support base material 82 in one direction to the support base material 82 and elongating the support base material 82 by 10% in one direction, the elongation force is reduced. After the release, the contraction load of the supporting base material 82 after 10 minutes has passed is 0.8 MPa or less, so that after the grinding and polishing of the semiconductor wafer 7 in the step [2A], the semiconductor wafer 7 The occurrence of warpage can be accurately suppressed or prevented, and the present invention has been completed. Further, since the occurrence of cracks in the semiconductor wafer 7 due to the warpage of the semiconductor wafer is also accurately suppressed or prevented, the yield of the manufactured semiconductor devices 10 is improved.

  The contraction load of the support base material 82 may be 0.8 MPa or less, but is preferably 0.6 MPa or less, and more preferably more than 0 MPa and 0.5 MPa or less. This makes it possible to more appropriately suppress or prevent the occurrence of warpage in the semiconductor wafer 7 after the grinding and polishing of the semiconductor wafer 7 in the step [2A].

  In addition, even if a concave portion is formed in 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], It also functions as a cushion layer for imparting a uniform grinding / polishing force. In order to provide such a function as a cushion layer to the support base material 82, the tan δ (hereinafter simply referred to as “tan δ”) of the dynamic elastic modulus of the support base material 82 in a temperature range from 20 ° C. to 60 ° C. The minimum value is preferably 0.3 or more, more preferably 0.35 or more and 2.0 or less. Thereby, the function as the cushion layer can be more reliably exerted, and the back surface 72 of the semiconductor wafer 7 can be ground and polished more uniformly over the entire surface thereof. The thickness can be reduced without unevenness in thickness. That is, the occurrence of thickness unevenness in the semiconductor wafer 7 can be accurately suppressed or prevented, and the semiconductor wafer 7 having a uniform thickness and reduced thickness can be obtained. This tan δ can be measured using a dynamic viscoelasticity measuring device or the like.

  Further, when tan δ (82) of the support base material 82 satisfies the above relationship, tan δ (82) of the support base material 82 and tan δ (81) of the adhesive layer 81 are tan δ (81) <tan δ (82). It is preferable to satisfy the relationship of 1.5 tan δ (81) <tan δ (82). By satisfying such a relational expression, the support base material 82 of the support base material 82 and the adhesive layer 81 included in the temporary fixing tape 200 is caused to function as a cushion layer, and the back surface 72 of the semiconductor wafer 7 is Can be ground and polished more uniformly over the whole.

  As the support base 82, for example, a base material containing a thermoplastic elastomer as a main material is used.

  The thermoplastic elastomer is not particularly limited. For example, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers such as polypropylene-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, and polyamide-based thermoplastic elastomers And the like, and one or more of these can be used in combination. Thereby, the contraction load can be relatively easily reduced to 0.8 MPa or less.

  Among these, a styrene-based thermoplastic elastomer is preferable. Thereby, the minimum value of tan δ of the support base material 82 in the temperature range of 20 ° C. or more and 60 ° C. or less can be easily set to 0.3 or more.

  Note that, in addition to the thermoplastic elastomer, the supporting base material 82 includes a softening agent such as mineral oil and process oil, a filler such as calcium carbonate, silica, talc, mica, and clay, a petroleum resin, a hydrocarbon resin, and a terpene. Additives such as resins, rosin esters, tackifiers such as phenolic resins, and plasticizers such as phthalic esters and amorphous polypropylene may be added. Thereby, the minimum value of tan δ of the support base material 82 in the temperature range of 20 ° C. or more and 60 ° C. or less can be reliably set to 0.3 or more.

  Examples of the styrene-based thermoplastic elastomer (TPS) include styrene-butadiene-styrene block copolymer (SBS), partially hydrogenated styrene-butadiene-styrene block copolymer (SBS), and styrene-butadiene- Completely hydrogenated styrene block copolymer (SBS), styrene-isobutylene-styrene block copolymer (SIBS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-isoprene-styrene (SIS) And styrene-ethylene-propylene-butylene block copolymer (SEPS). Among them, partially hydrogenated styrene-butadiene-styrene block copolymer (SBS) and styrene-butadiene-styrene block copolymer are exemplified. Complete water of coalescence (SBS) Objects, styrene - isobutylene - is preferably at least one of styrene block copolymer (SIBS). By using one or more of these compounds in combination, the minimum value of tan δ can be more reliably set to 0.3 or more.

  In addition, since these thermoplastic elastomers are materials that can transmit energy rays such as light (visible light, near infrared rays, and ultraviolet rays), X-rays, and electron beams, in the step [4A], the energy rays are supported. The adhesive layer 81 can be radiated by transmitting the support base 82 from the base 82 side.

  Further, the support base material 82 may contain an antioxidant, a light stabilizer, a lubricant, a dispersant, a neutralizer, a colorant, and the like.

  The thickness of the support base material 82 is not particularly limited, but is, for example, preferably 10 μm or more and 400 μm or less, more preferably 30 μm or more and 300 μm or less, and still more preferably 80 μm or more and 300 μm or less. When the thickness of the supporting base material 82 is within this range, the grinding and polishing of the semiconductor wafer 7 in the step [2A] can be performed with excellent workability. Further, the effect obtained by setting the minimum value of tan δ to 0.3 or more can be more remarkably exhibited.

  Further, it is preferable that a functional group such as a hydroxyl group and an amino group, which is reactive with the constituent material contained in the adhesive layer 81, is exposed on the surface of the support base material. In this case, for example, the functional group can be exposed by performing a corona treatment on the surface of the support base material 82.

  In addition, the support base material 82 may be 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.

  Note that, in the step [1A], an extension force for extending the temporary fixing tape 200 in at least one direction is applied to the temporary fixing tape 200 before the temporary fixing tape 200 is attached to the semiconductor wafer 7. When the temporary fixing tape 200 has a disk shape corresponding to the shape of the semiconductor wafer 7, the direction may be a radial direction from the center of the temporary fixing tape 200 or the temporary fixing tape 200. One direction may pass through the center of 200. Furthermore, when the planar shape of the temporary fixing tape 200 is a rectangular sheet, it may be one or both of the longitudinal direction and the lateral direction.

<Adhesive layer 81>
The adhesive layer 81 adheres to 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 by the supporting base material 82 via this. It has the function of supporting by. Further, in the step [4A], the adhesive layer 81 is reduced in adhesiveness to the semiconductor wafer 7 by irradiating the adhesive layer 81 with energy rays, whereby the adhesive layer 81 and the semiconductor wafer 7 In a state where peeling can easily occur.

  When the temporary fixing tape 200 is temporarily fixed, that is, when the temporary fixing tape 200 is attached to the semiconductor wafer 7 in the step [1A], the adhesive layer 81 has a depth of 0.03 mm and a width of 0 mm. The follow-up rate of the adhesive layer 81 before the energy beam irradiation with respect to the recess of 0.3 mm is preferably 70% or more, more preferably 80% or more and 100% or less. If the follow-up rate of the adhesive layer 81 with respect to the concave portion having such a size is within the above range, in the step [2A], when grinding or polishing the back surface 72, it is necessary to wash away grinding chips and cool the semiconductor wafer. It is possible to accurately suppress or prevent the grinding water used for this purpose from entering the recess. Further, in the step [2A], the concave portion is filled with the adhesive layer 81 at a high following rate such that the following rate is within the above range, so that the support base material 82 supports the semiconductor wafer 7 more. It will be stable. Therefore, since the back surface 72 of the semiconductor wafer 7 can be uniformly ground and polished over the entire surface, the thickness of the semiconductor wafer 7 can be reduced without unevenness in thickness.

  Further, the pressure-sensitive adhesive layer 81 preferably has a shear adhesive force at a temperature of 23 ° C. of 0.8 MPa or more, and 0.9 MPa or more and 2.0 MPa or less before irradiation of the adhesive layer 81 with energy rays. Is more preferred. When the shear adhesive force of the adhesive layer 81 indicates such a magnitude, peeling occurs between the adhesive layer 81 and the semiconductor wafer 7 when the back surface 72 is ground or polished in the step [2A]. That is, the peeling of the adhesive layer 81 in the concave portion can be accurately suppressed or prevented.

  In addition, this shear adhesive strength prepared two test pieces comprised of stainless steel, and these test pieces were joined to each other via an adhesive layer 81 of 25 mm × 25 mm on one side. Thereafter, both ends of the test piece are pulled at a pulling speed of 200 mm / min so that the test pieces are separated from each other in the plane direction, and the maximum when the joint part where the test pieces are joined via the adhesive layer 81 is broken is broken. It can be obtained by measuring the load.

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

Hereinafter, each component contained in the resin composition will be sequentially described in detail.
(1) Acrylic copolymer The acrylic copolymer (acrylic resin) has an adhesive property, and before applying energy rays to the adhesive layer 81, the adhesive property to the semiconductor wafer 7 is changed to the adhesive layer 81. It is included in the resin composition to provide. In addition, when the resin composition contains an acrylic copolymer, the heat resistance of the adhesive layer 81 can be improved.

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

  The (meth) acrylate is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate , Isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, (meth) 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, tri (meth) acrylate Syl, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, alkyl (meth) acrylates such as octadecyl (meth) acrylate, (meth) Examples thereof include cycloalkyl (meth) acrylates such as cyclohexyl acrylate and aryl (meth) acrylates such as phenyl (meth) acrylate, and one or more of these are used in combination. be able to. Among these, alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and octyl (meth) acrylate It is preferable that (Meth) acrylic acid alkyl esters are particularly excellent in heat resistance and can be obtained relatively easily and inexpensively.

  In this specification, the term “(meth) acrylate” is used to include both acrylate and methacrylate.

  In addition, as the acrylic copolymer, those containing a copolymerizable monomer in addition to (meth) acrylic acid ester as a monomer component constituting the polymer are preferably used so as to satisfy the above relational expression. Can be

  Such a copolymerizable monomer is not particularly limited, but for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, (meth) Hydroxyl group-containing monomers (hydroxyl-containing (meth) acrylate) such as 6-hydroxyhexyl acrylate, epoxy group-containing monomers such as glycidyl (meth) acrylate, (meth) acrylic acid, itaconic acid, maleic acid, and fumaric acid Carboxyl group-containing monomers such as, crotonic acid and isocrotonic acid, acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl ( (Meth) acrylamide, N-methylol (meth) acrylamide Amide group-containing monomers (amide group-containing (meth) acrylate) such as N-methylolpropane (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, amino (meth) acrylate Amino group-containing monomers such as ethyl, N, N-dimethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, cyano group-containing monomers such as (meth) acrylonitrile, (meth) acrylic acid Alkoxy group-containing monomers such as methoxyethyl, ethoxyethyl (meth) acrylate, N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine , N-vinylpyrazine, N Monomers having a nitrogen atom-containing ring, such as vinyl pyrrole, N-vinyl imidazole, N-vinyl oxazole, N-vinyl morpholine, N-vinyl caprolactam, N- (meth) acryloyl morpholine, and the like. Alternatively, two or more kinds can be used in combination. Among these, the copolymerizable monomer preferably contains at least one of a carboxyl group-containing monomer and an amide group-containing monomer. Thereby, the adhesive layer 81 containing a copolymer derived from these monomers as an acrylic copolymer can be filled in the recess provided in the semiconductor wafer 7 with better followability.

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

  Further, the copolymerizable monomer may be included in the main chain terminal of the polymer constituting the acrylic copolymer, or may be included in the main chain, and further, may be included in the main chain terminal. It may be contained both in the main chain.

  Further, the copolymerizable monomer may contain a polyfunctional monomer for the purpose of crosslinking polymers and the like.

  Examples of the polyfunctional monomer 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. One or more of these may be used. It can be used in combination.

  In addition, such an acrylic copolymer (polymer) can be produced by polymerizing a single monomer component or a mixture of two or more monomer components. Further, the 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, and the like.

  As described above, the acrylic copolymer obtained by polymerizing the monomer component described above includes an acrylic copolymer having a carbon-carbon double bond in a side chain, in a main chain or at a terminal of the main chain. (Sometimes referred to as “double bond-introduced acrylic copolymer”). When the acrylic copolymer is a double bond-introduced acrylic copolymer, even if the addition of an energy ray polymerizable compound (curable resin) described later is omitted, the obtained adhesive layer 81 has the above-described structure. The function as the formed adhesive layer 81 can be exhibited.

  The method for synthesizing such a double bond-introduced acrylic copolymer (that is, a method for introducing a carbon-carbon double bond into an acrylic copolymer) is not particularly limited, and examples thereof include a copolymerizable monomer. After copolymerizing using a monomer having a functional group as a base to synthesize a functional group-containing acrylic copolymer (sometimes referred to as a “functional group-containing acrylic copolymer”), A compound having a functional group capable of reacting with a functional group in the acrylic copolymer and a carbon-carbon double bond (sometimes referred to as a “carbon-carbon double bond-containing reactive compound”) is converted into a functional compound. The group-containing acrylic copolymer is subjected to a condensation reaction or an addition reaction while maintaining the energy-ray curability (energy-ray polymerizability) of the carbon-carbon double bond, whereby a double bond-introduced acrylic copolymer is obtained. Synthesize coalescence Method, and the like.

  In addition, when a carbon-carbon double bond-containing reactive compound is subjected to a condensation reaction or an addition reaction with a functional group-containing acrylic copolymer, the reaction can be effectively advanced by using a catalyst. Such a catalyst is not particularly limited, but a tin-based catalyst such as dibutyltin dilaurate is preferably used. The content of the tin-based catalyst is not particularly limited, but is preferably, for example, 0.05 parts by weight or more and 1 part by weight or less based on 100 parts by weight of the functional group-containing acrylic copolymer.

  The weight average molecular weight of the acrylic copolymer is preferably set to 300,000 to 5,000,000, more preferably to 400,000 to 3,000,000, and further preferably to 500,000 to 1.5,000,000. By setting the weight average molecular weight of the acrylic copolymer within the above range, in the step [4A], when the temporary fixing tape 200 is peeled from the semiconductor wafer 7, the adhesive layer is formed in the concave portion provided on the surface 71. It is possible to accurately suppress or prevent a part of 81 from remaining.

  The acrylic copolymer is a functional group (such as a hydroxyl group or a carboxyl group (particularly, a hydroxyl group)) having a reactivity with a crosslinking agent or an energy ray polymerization initiator (a photopolymerization initiator). (Functional group). Thereby, since the crosslinking agent and the energy ray polymerization initiator are connected to the acrylic resin as the polymer component, it is possible to accurately suppress or prevent the leakage of the crosslinking agent and the energy ray polymerization initiator from the adhesive layer 81. . As a result, the adhesiveness of the adhesive layer 81 to the semiconductor wafer 7 is surely reduced by the energy beam irradiation in the step [4A].

  Further, the acrylic copolymer is preferably blended in an amount of 30 wt% or more and 70 wt% or less, more preferably 35 wt% or more and 65 wt% or less in the adhesive layer 81 (resin composition). 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] causes the adhesive layer 81 to remain in the recess. And can be implemented with excellent accuracy. In addition, when the temporary fixing tape 200 is attached to the semiconductor wafer 7 in the step [1A], the follow-up rate of the adhesive layer 81 to the concave portion can be set within the above range. Therefore, when grinding / polishing the back surface 72 of the semiconductor wafer 7 in the step [2A], it is possible to more accurately suppress or prevent the intrusion of the grinding water into the concave portion, and to prevent the semiconductor wafer 7 from being intruded. 7 can be reduced in thickness without causing thickness unevenness.

(2) Energy ray polymerizable compound The energy ray polymerizable compound has curability to be polymerized by irradiation with energy rays and, as a result, to be cured. By 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 decreases.

  Such an energy ray polymerizable compound has, for example, at least two or more polymerizable carbon-carbon double bonds capable of three-dimensionally cross-linking by irradiation with an energy ray such as an ultraviolet ray or an electron beam in a molecule as a functional group. Low molecular weight compounds are used.

  Specifically, for example, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, tetramethylolmethanetetra (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) ) Esterified product of (meth) acrylic acid and polyhydric alcohol such as acrylate, polyethylene glycol di (meth) acrylate and glycerin di (meth) acrylate, A cyanurate-based compound having a carbon-carbon double bond-containing group such as a acrylate oligomer, 2-propenyl-di-3-butenyl cyanurate, tris (2-acryloxyethyl) isocyanurate, tris (2-methacrylic) Roxyethyl) isocyanurate, 2-hydroxyethyl bis (2-acryloxyethyl) 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) isocyanate Isocyanurate compounds having a carbon-carbon double bond-containing group such as nurate, commercially available oligoester acrylates, aromatic and aliphatic urethane acrylates, and the like. Alternatively, two or more kinds can be used in combination. Among them, it is preferable to include an oligomer having 6 or more functional groups, and it is more preferable to include an oligomer having 15 or more functional groups. Thereby, the energy ray polymerizable compound can be more reliably cured by irradiation with the energy ray. Further, such an energy ray polymerizable compound is preferably a urethane acrylate oligomer. This allows the adhesive layer 81 to have appropriate flexibility. Therefore, in the step [4A], when the temporary fixing tape 200 is peeled off from the semiconductor wafer 7, a crack is generated in the layer of the adhesive layer 81, and peeling at the crack is prevented. It is possible to accurately suppress or prevent the adhesive layer 81 from remaining therein.

  The urethane acrylate is not particularly limited. For example, a polyol compound such as a polyester type or a polyether type and a polyvalent isocyanate compound (for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate) Isocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane 4,4-diisocyanate, etc.) to give a terminal isocyanate urethane prepolymer having hydroxyl groups ( Examples thereof include those obtained by reacting (meth) acrylate (for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, polyethylene glycol (meth) acrylate).

  The weight average molecular weight of the energy ray polymerizable compound is preferably about 100 to 10000, more preferably about 200 to 5000. Further, the number of functional groups of the energy ray polymerizable compound is preferably about 1 to 10 functional groups, and more preferably about 2 to 6 functional groups. By satisfying such a relationship, the above effect can be more remarkably exhibited.

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

  By adjusting the compounding amount of the energy ray polymerizable compound as described above, the peeling of the temporary fixing tape 200 from the semiconductor wafer 7 in the step [4A] causes the adhesive layer 81 to remain in the recess. And can be implemented with excellent accuracy. In addition, when the temporary fixing tape 200 is attached to the semiconductor wafer 7 in the step [1A], the follow-up rate of the adhesive layer 81 to the concave portion can be set within the above range. Therefore, when grinding / polishing the back surface 72 of the semiconductor wafer 7 in the step [2A], it is possible to more accurately suppress or prevent the intrusion of the grinding water into the concave portion, and to prevent the semiconductor wafer 7 from being intruded. 7 can be reduced in thickness without causing thickness unevenness.

  In addition, this energy ray polymerizable compound, when using a double bond-introduced acrylic resin as the acrylic resin described above, that is, a carbon-carbon double bond, a side chain, in the main chain or in the main chain. When a resin having a terminal is used, its addition to the resin composition may be omitted. This is because, when the acrylic resin is a double bond-introduced acrylic resin, the adhesive layer 81 is formed by the irradiation of energy rays due to the carbon-carbon double bond function of the double bond-introduced acrylic resin. Is cured, whereby the adhesive strength of the adhesive layer 81 is reduced.

(3) Energy Beam Polymerization Initiator The pressure-sensitive adhesive layer 81 is one in which the adhesiveness to the semiconductor wafer 7 is reduced by the irradiation of the energy beam. Preferably contains an energy ray polymerization initiator (photopolymerization initiator) in order to facilitate the initiation of polymerization of the energy ray polymerizable compound.

  Examples of the energy ray polymerization initiator include 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-hydroxycyclohexyl phenyl ketone, Michler's ketone, acetophenone, methoxyacetophen 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-hydroxycyclohexyl phenyl ketone, benzyl dimethyl ketal, 2-hydroxymethyl phenyl propane, 2-naphthalene sulfonyl chloride, 1-phenone-1, 1-propanedione-2- (o-ethoxycarbonyl) oxime, benzophenone, benzoylbenzoic acid, 4,4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzofur Enone, 4,4′-dichlorobenzophenone, 3,3′-dimethyl-4-methoxybenzophenone, o-acryloxybenzophenone, p-acryloxybenzophenone, o-methacryloxybenzophenone, p-methacryloxybenzophenone, p- (meth) ) Benzophenone-4-acrylates such as acryloxyethoxybenzophenone, 1,4-butanediol mono (meth) acrylate, 1,2-ethanediol mono (meth) acrylate, and 1,8-octanediol mono (meth) acrylate Carboxylic acid esters, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthio Sanson, 2,4-diisopropylthioxanthone, azobisisobutyronitrile, β-chloranthraquinone, camphorquinone, halogenated ketone, acylphosphinoxide, acylphosphonate, polyvinylbenzophenone, chlorothioxanthone, dodecylthioxanthone, Dimethylthioxanthone, diethylthioxanthone, 2-ethylanthraquinone, t-butylanthraquinone, 2,4,5-triary-imidazole dimer, and the like, and one or more of these may be used in combination. Can be.

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

  Further, 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 at 1.5 wt% or more and 4.5 wt% or less. More preferably, it is blended at 2.8 wt%.

  By adjusting the blending amount of the energy ray polymerization initiator as described above, the peeling of the temporary fixing tape 200 from the semiconductor wafer 7 in the step [4A] causes the adhesive layer 81 to remain in the recess. And can be implemented with excellent accuracy. In addition, when the temporary fixing tape 200 is attached to the semiconductor wafer 7 in the step [1A], the follow-up rate of the adhesive layer 81 to the concave portion can be set within the above range. Therefore, when grinding / polishing the back surface 72 of the semiconductor wafer 7 in the step [2A], it is possible to more accurately suppress or prevent the intrusion of the grinding water into the concave portion, and to prevent the semiconductor wafer 7 from being intruded. 7 can be reduced in thickness without causing thickness unevenness.

(4) Crosslinking agent The crosslinking agent is included in the resin composition to improve the curability of the energy ray polymerizable compound.

  The crosslinking agent is not particularly limited, but, for example, isocyanate-based crosslinking agent, epoxy-based crosslinking agent, urea-based crosslinking agent, methylol-based crosslinking agent, chelating-based crosslinking agent, aziridine-based crosslinking agent, melamine-based crosslinking agent, polyvalent Examples include a metal chelate crosslinking agent, an acid anhydride crosslinking agent, a polyamine crosslinking agent, and a carboxyl group-containing polymer crosslinking agent. Among these, an isocyanate-based crosslinking agent is preferable.

  The isocyanate-based crosslinking agent is not particularly limited, for example, a polyisocyanate compound of a polyvalent isocyanate and a trimer of a polyisocyanate compound, a trimer of a terminal isocyanate compound obtained by reacting a polyisocyanate compound with a polyol compound Alternatively, a blocked polyisocyanate compound in which a terminal isocyanate urethane prepolymer is blocked with phenol, oximes, or the like may be used.

  Examples of the polyvalent isocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylene diisocyanate, diphenylmethane-4,4'-diisocyanate, and diphenylmethane. -2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, 4,4'-diphenylether diisocyanate, , 4 '-[2,2-bis (4-phenoxyphenyl) propane] diisocyanate, 2,2,4-trimethyl-hexamethylene diisocyanate, 2,4- Condensation compound of Li diisocyanate and trimethylol propane, 2,6-fused compounds of tolylene diisocyanate and trimethylol propane and the like, can be used singly or in combination of two or more of them. Among them, 2,4-tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, hexamethylene diisocyanate, a condensation compound of 2,4-tolylene diisocyanate and trimethylolpropane, and 2,6-tolylene diisocyanate and At least one polyvalent isocyanate selected from the group consisting of condensation compounds of methylolpropane is preferred.

  Further, the crosslinking agent is preferably blended in the adhesive layer 81 (resin composition) at 0.5 wt% or more and 6.5 wt% or less, and more preferably at 1.0 wt% or more and 5.5 wt% or less. More preferably, it is even more preferably blended at 5.3 wt%. By adjusting the blending amount of the crosslinking agent as described above, the separation of the temporary fixing tape 200 from the semiconductor wafer 7 in the step [4A] can be performed without leaving the adhesive layer 81 in the concave portion. It can be implemented with excellent accuracy. In addition, when the temporary fixing tape 200 is attached to the semiconductor wafer 7 in the step [1A], the follow-up rate of the adhesive layer 81 to the concave portion can be set within the above range. Therefore, when grinding / polishing the back surface 72 of the semiconductor wafer 7 in the step [2A], it is possible to more accurately suppress or prevent the intrusion of the grinding water into the concave portion, and to prevent the semiconductor wafer 7 from being intruded. 7 can be reduced in thickness without causing thickness unevenness.

(5) Other components Furthermore, in addition to the above-mentioned components (1) to (4), the resin composition constituting the adhesive layer 81 includes, as other components, a tackifier, an antioxidant, and a tackifier. , A filler, a colorant, a flame retardant, a softener, an antioxidant, a plasticizer, a surfactant, and the like.

  The tackifier among these is not particularly limited. For example, rosin resin, terpene resin, coumarone resin, phenol resin, aliphatic petroleum resin, aromatic petroleum resin, aliphatic aromatic copolymer petroleum Resins and the like can be mentioned, and one or more of these can be used in combination.

  The thickness T of the adhesive layer 81 is not particularly limited. However, when the depth of a concave portion provided on the surface 71 of the semiconductor wafer 7 is D, the relationship of 1.2D <T <5.0D is satisfied. It is more preferable that the relationship 1.5D <T <4.0D is satisfied. Thereby, the adhesive layer 81 can be filled with an excellent following rate into the concave portion provided on the surface 71 of the semiconductor wafer 7.

  Specifically, the thickness of the adhesive layer 81 is preferably, for example, 20 μm or more and 100 μm or less, more preferably 30 μm or more and 90 μm or less, and further preferably 40 μm or more and 90 μm or less. By setting the thickness of the adhesive layer 81 within the above range, the adhesive layer 81 can be filled at the above-described following rate, and the adhesive layer 81 has a good quality before energy is applied to the adhesive layer 81. In addition to exerting the adhesive force, after the energy is applied to the adhesive layer 81, a good peeling property is exhibited between the adhesive layer 81 and the semiconductor wafer 7.

  In addition, the adhesive layer 81 may be configured by a laminate (multilayer body) in which a plurality of layers composed of different resin compositions are laminated.

  Further, in the present embodiment, it has been described that it is preferable that the follow-up rate with respect to a concave portion having a depth of 0.03 mm and a width of 0.3 mm is 70% or more. The adhesive layer 81 can be filled with good followability even in concave portions having different sizes formed on the semiconductor wafer 7 having the chips 20. Therefore, at the time of the temporary fixing, it is possible to accurately suppress or prevent the intrusion of water into the concave portions provided in the semiconductor wafer 7 and to set the back surface 72 of the semiconductor wafer 7 over the entirety. Grinding and polishing can be performed uniformly.

  In addition, it is preferable that the separator 200 is laminated on the adhesive layer 81 before the temporary fixing tape 200 is attached to the semiconductor wafer 7. This makes it possible to reliably prevent dust and the like from unintentionally adhering to the adhesive layer 81 during storage and transportation of the temporary fixing tape 200.

  The separator is not particularly limited, and examples thereof include a polypropylene film, a polyethylene film, and a polyethylene terephthalate film.

  Furthermore, since the separator is peeled off when the temporary fixing tape 200 is used, a separator whose surface has been release-treated may be used. Examples of the release treatment include a treatment of coating the surface of the separator with a release agent and a treatment of forming fine irregularities on the surface of the separator. Note that examples of the release agent include silicone-based, alkyd-based, and fluorine-based release agents.

  In the present embodiment, the case where the semiconductor device 10 is applied to a quad flat package (QFP) and the semiconductor device 10 having such a configuration is manufactured using the temporary fixing tape 200 has been described. The temporary fixing tape 200 can be applied to the manufacture of various types of semiconductor packages, for example, a dual in-line package (DIP), a chip carrier with plastic leads (PLCC),・ Profile 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 key Rear package (TCP), ball grid array (BGA), chip size package (CSP), matrix array package ball grid array (MAPBGA), chip stacked chip size package, etc. Memory and logic devices.

  As described above, the temporary fixing tape of the present invention has been described based on the illustrated embodiment, but the present invention is not limited to this. For example, in the temporary fixing tape of the present invention, each configuration is the same. Can be replaced with an arbitrary one that can exhibit the function of, or an arbitrary configuration can be added.

Next, specific examples of the present invention will be described.
The present invention is not limited to the description of these examples.

1. Preparation of Raw Material for Forming Adhesive Layer First, the raw materials used for forming the adhesive layer in the production of the temporary fixing tapes of the respective Examples and Comparative Examples are shown below.

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

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

(Crosslinking agent A)
As the crosslinking agent A, a trimethylolpropane condensation compound of toluene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., product number: Coronate L) was prepared.

(Energy ray polymerization initiator A)
As the energy ray polymerization initiator A, 2,2-dimethoxy-2-phenylacetophenone (manufactured by BASF, product number: Irgacure 651) was prepared.

2. Preparation of Raw Material for Forming Support Base Next, the raw materials used for forming the support base when producing the temporary fixing tapes of the examples and the comparative examples are shown below.

(Partially hydrogenated styrene-butadiene-styrene block copolymer)
A partially hydrogenated styrene-butadiene-styrene block copolymer (manufactured by Asahi Kasei Chemicals Corporation, product number: L609) was prepared.

(Styrene-isobutylene-styrene block copolymer)
A styrene-isobutylene-styrene block copolymer (manufactured by Kaneka Corporation, product number: SIBSTAR062M) was prepared.

(Styrene-isoprene-styrene block copolymer)
A styrene-isoprene-styrene block copolymer (manufactured by Zeon Corporation, product number: Quintac 3433N) was prepared.

(Ethylene-butene copolymer)
An ethylene-butene copolymer (manufactured by Tosoh Corporation, product number: LUMITAC 43-1) was prepared.

(Photopolymerizable urethane acrylate oligomer)
As a resin composition for obtaining a photopolymerizable urethane acrylate oligomer, a terminal isocyanate urethane prepolymer obtained by reacting 2,4-tolylene diisocyanate with 2-hydroxyethyl methacrylate is obtained. A resin composition was prepared by blending 100 parts by weight of the mixture and 2.0 parts of 2,2-dimethoxy-2-phenylacetophenone (manufactured by BASF, product number: Irgacure 651) as the energy ray polymerization initiator A.

3. Production of temporary fixing tape [Example 1]
As the support base material 82, a partially hydrogenated styrene-butadiene-styrene block copolymer having a thickness of 200 μm was put into a hopper of a single screw extruder, kneaded by an extruder, formed by a T die, and cooled by a cooling die. And cooled to prepare a film. At this time, the temperature of the extruder and the T-die was 200 ° C., and the temperature of the cooling roll was 25 ° C.

  Next, an acrylic copolymer A (49.5 wt%), an energy ray polymerizable compound A (42.4 wt%), a crosslinking agent A (5.3 wt%), and an energy ray polymerization initiator A (2.8 wt%) ) Was prepared to contain a liquid material containing the resin composition. The ratio of the resin composition is parts by mass in terms of solid content.

  This liquid material is die-coated on a release PET film such that the thickness of the adhesive layer 81 after drying is 50 μm, and is then dried at 80 ° C. for 1 minute. An adhesive layer 81 was formed on one surface). Thereafter, lamination was performed so that the adhesive layer 81 on the release PET film was in contact with the support base material 82, thereby producing a temporary fixing tape of Example 1 in which the adhesive layer 81 was formed on the upper surface of the support base material 82.

[Example 2]
A temporary fixing tape was produced in the same manner as in Example 1 except that a styrene-isobutylene-styrene block copolymer was used as a raw material for forming the support base material 82.

[Example 3]
A temporary fixing tape was produced in the same manner as in Example 1 except that a styrene-isoprene-styrene block copolymer was used as a raw material for forming the support base material 82.

[Comparative Example 1]
A temporary fixing tape was produced in the same manner as in Example 1 except that an ethylene-butene copolymer was used as a raw material for forming the support base material 82.

[Comparative Example 2]
As a raw material for forming the supporting base material 82, a resin composition for obtaining a photopolymerizable urethane acrylate-based oligomer is used, and after applying the resin composition by die coating, ultraviolet light is applied under the condition of a light quantity of 250 mJ / cm ^2. A temporary fixing tape was produced in the same manner as in Example 1 except that the support base material 82 was formed by irradiation.

4. Evaluation of Temporary Fixing Tape 4.1 Evaluation of Shrinkage Load of Supporting Substrate Using a raw material for forming a supporting substrate, which was prepared when preparing the temporary fixing tapes of each of the examples and comparative examples, a support base was used. A material 82 was formed. Next, an extension force for extending the support base material 82 in one direction is applied to the support base member 82 to extend the support base member 82 by 10% in the one direction, and then the extension force is released. The shrink load at 82 was measured using a tensile tester.

4.2 Evaluation of Warpage of Semiconductor Wafer A 6-inch semiconductor wafer 7 having a thickness of 650 μm was prepared by providing a plurality of concave portions having a depth of 0.03 mm and a width of 0.3 mm on the surface 71. The temporary fixing tape obtained in each of the examples and the comparative examples was attached to 71 by pressing with a roller having a diameter of 95 mm, a width of 300 mm, and a weight of 13.3 kgf after the release PET film was peeled off.

  Thereafter, the back surface 72 of the semiconductor wafer 7 was polished to a thickness of 50 μm using a polishing apparatus (manufactured by Disco, “Product name: DAG810”).

  Then, the warpage of the semiconductor wafer 7 after polishing was measured by measuring with a ruler.

<Evaluation criteria for warpage in semiconductor wafers>
A: The amount of warpage in the semiconductor wafer is less than 2 mm.
〇: The amount of warpage in the semiconductor wafer is 2 mm or more and less than 3 mm.
X: The amount of warpage in the semiconductor wafer is 3 mm or more.
Table 1 shows the evaluation results.

4.3 Evaluation of tan δ of dynamic viscoelasticity The supporting base material 82 was formed using the raw material for forming the supporting base material prepared at the time of producing the temporary fixing tape of each of the examples and the comparative examples. Next, the obtained support base material 82 was subjected to a dynamic viscoelasticity measurement device (manufactured by SII Nanotechnology Co., Ltd., product name: DMS6100) at a frequency of 1 Hz and a temperature of 20 ° C or more and 60 ° C or less. The minimum value of the tan δ of the tensile stress in the temperature range was measured.

4.4 Evaluation of Thickness of Semiconductor Wafer A plurality of recesses having a depth of 0.03 mm and a width of 0.3 mm are provided on the surface 71, and a semiconductor wafer 7 having a thickness of 50 μm is prepared. After the release PET film was peeled off, the temporary fixing tapes obtained in the respective Examples and Comparative Examples were adhered by pressing with a roller having a diameter of 95 mm, a width of 300 mm, and a weight of 13.3 kgf.

  Thereafter, the back surface 72 of the semiconductor wafer 7 was polished to a thickness of 50 μm using a polishing apparatus (manufactured by Disco, “Product name: DAG810”).

  Then, the thickness of the semiconductor wafer 7 after polishing was measured at 33 points at random positions. Then, the difference between the maximum value and the minimum value was determined based on these measured values.

<Evaluation criteria for thickness of semiconductor wafer>
A: The difference between the maximum value and the minimum value in the semiconductor wafer is less than 5 μm.
〇: The difference between the maximum value and the minimum value in the semiconductor wafer is 5 μm or more and less than 10 μm.
X: The difference between the maximum value and the minimum value in the semiconductor wafer is 10 μm or more.
Table 1 shows the evaluation results.

4.5 Evaluation of Following Ratio of Temporary Fixing Tape A semiconductor wafer 7 having a plurality of recesses 0.03 mm in depth and 0.3 mm in width on the surface 71 was prepared. The temporary fixing tapes obtained in the examples and the comparative examples were applied by peeling the release PET film, and then pressing the tape with a roller having a diameter of 95 mm, a width of 45 mm, and a weight of 2.0 kgf.

  Then, the following rate of the adhesive layer 81 with respect to the concave portion was measured by dividing the height of the convex portion of the temporary fixing tape after being peeled from the concave portion by UV irradiation by the depth of the concave portion. The evaluation was performed in the light of In addition, the above-mentioned height and depth were measured by an interference microscope (New View 7300, manufactured by ZYGO).

<Evaluation criteria for follow-up rate of temporary fixing tape>
A: The follow-up rate of the adhesive layer is 80% or more.
〇: The following ratio of the adhesive layer is 70% or more and less than 80%.
X: The following rate of the adhesive layer is less than 70%.
Table 1 shows the evaluation results.

4.6 Evaluation of Shear Adhesive Strength of Adhesive Layer 81 Before Energy Beam Irradiation Two test pieces made of aluminum were prepared, and these test pieces were joined to each other on one surface. Using a liquid material prepared at the time of producing the temporary fixing tape of each example and each comparative example, an adhesive layer 81 of 25 × 25 mm in length and width was formed, and then both ends of the test piece were attached to each other. The test pieces are pulled at a pulling speed of 200 mm / min so as to be separated in the plane direction, and the maximum load at the time when the joint portion where the test pieces are joined via the adhesive layer 81 is broken is measured. Was evaluated.

<Evaluation criteria for shear adhesive strength of adhesive layer 81>
〇: The shear adhesive strength of the adhesive layer 81 is 0.8 MPa or more.
X: The shear adhesive force of the adhesive layer 81 is less than 0.8 MPa.
Table 1 shows the evaluation results.

  As is clear from Table 1, in each of the examples, the magnitude of the shrinkage load on the supporting base material was 0.8 MPa or less, whereby the magnitude of the warpage generated in the semiconductor wafer 7 was reduced by 2 MPa. It can be said that the occurrence of warpage in the semiconductor wafer 7 is suppressed.

  On the other hand, in each of the comparative examples, the magnitude of the shrinkage load on the supporting base material is not less than 0.8 MPa, but is not less than 0.9 MPa, and as a result, the warpage generated in the semiconductor wafer 7. Was 3.0 mm or more, indicating that the generation of warpage in the semiconductor wafer 7 was not suppressed.

2 Adhesive layer 4 Base material 7 Semiconductor wafer 9 Wafer ring 10 Semiconductor device 20 Semiconductor chip 21 Electrode pad 22 Wire 30 Die pad 40 Lead 50 Mold part 60 Adhesive layer 71 Front surface 72 Back surface 81 Adhesive layer 82 Support base material 100 Semiconductor wafer processing Adhesive tape 121 Outer peripheral part 122 Central part 200 Temporary fixing tape

Claims (7)

Support substrate, comprising an adhesive layer laminated on one surface of the support substrate,
The substrate is temporarily fixed to the support base via the adhesive layer for processing the substrate, and the substrate is detached from the support base by irradiating the adhesive layer with energy rays after processing the substrate. It is a temporary fixing tape used for causing
The substrate includes a plurality of recesses on a protection surface located on a side opposite to a processing surface on which the processing is performed,
When the supporting base material is applied with an elongating force to extend the supporting base material in one direction to the supporting base material and elongates the supporting base material by 10% in the one direction, the elongating force is released, and thereafter, when 10 minutes have elapsed. The shrinkage load is 0.8 MPa or less, and the supporting base material has a minimum value of tanδ of dynamic viscoelasticity in a temperature range of 20 ° C. or more and 60 ° C. or less of 0.4 or more ,
The adhesive layer has a shear adhesive force of 0.8 MPa or more under a temperature condition of 23 ° C. before irradiation of the adhesive layer with energy rays, and the adhesive layer has a thickness of at least 30% before irradiation of the adhesive layer with energy rays. 3. The temporary fixing tape according to claim 1, wherein a follow-up rate of the concave portion having a depth of 0.03 mm and a width of 0.3 mm is 80% or more and 100% or less .   The temporary fixing tape according to claim 1, wherein the support base material contains a thermoplastic elastomer as a main material.   The temporary fixing tape according to claim 2, wherein the thermoplastic elastomer includes a styrene-based elastomer.   The styrene elastomer is at least one of a partially hydrogenated styrene-butadiene-styrene copolymer, a completely hydrogenated styrene-butadiene-styrene copolymer, and a styrene-isobutylene-styrene copolymer. The temporary fixing tape according to claim 3.   The temporary fixing according to any one of claims 1 to 4, wherein the adhesive layer contains an acrylic copolymer, a crosslinking agent, an energy ray polymerizable compound polymerized by irradiation with energy rays, and an energy ray polymerization initiator. Tape.   The temporary fixing tape according to any one of claims 1 to 5, wherein the substrate is a semiconductor wafer.   7. The temporary fixing tape according to claim 6, wherein the processing is a semiconductor wafer grinding for reducing a thickness of the semiconductor wafer by grinding a processing surface of the semiconductor wafer.

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