JP5006015B2 - Semiconductor wafer surface protective tape and semiconductor chip manufacturing method using the same - Google Patents

Description

The present invention relates to a semiconductor wafer surface protective tape having heat resistance used in a step of bonding a die bond sheet to a ground surface after grinding a back surface of a semiconductor wafer and a method of manufacturing a semiconductor chip using the same.

In recent years, the need for miniaturization of mounted components has further increased, and the miniaturization technology for semiconductor packaging has been evolving. As a result, semiconductor chips are also required to be made thinner and smaller, and at the same time, technical needs for compact packaging of these thin and small semiconductor chips will continue to increase. Desirably, it is required to be packaged in approximately the same size as the dimensions of the semiconductor chip.
Conventionally, these semiconductor chips are obtained by grinding the back side without a circuit pattern until a predetermined thickness is obtained in a back grinding process in a state where the surface protection tape is bonded to the circuit pattern surface of the semiconductor wafer. And then cut and separated by a dicing apparatus or the like in a dicing process in a state where it is supported and fixed to a dicing tape. After that, the chip-formed semiconductor chip is die-bonded to a continuously flowing lead frame by a pick-up die bonder or the like, and is finally molded and molded with a mold resin.

  This is a method of die bonding to a lead frame. Conventionally, a method of die bonding a chip-shaped semiconductor chip to a die pad of a lead frame coated with a liquid adhesive by a pick-up die bonder or the like has been common. In this case, it is very difficult to control the required coating amount for each die bonding, and furthermore, since it is liquid, the liquid adhesive slightly protrudes from the dimensions of the semiconductor chip when the semiconductor chip is die bonded. As a result, it is necessary to package with a size somewhat larger than the size of the semiconductor chip, which is not a desirable method from the viewpoint of packaging with the size almost the same as the size of the semiconductor chip as described above.

On the other hand, there is a method of using a sheet-like adhesive (die bond sheet) as an adhesive for die bonding. As a method of using this die bond sheet, there is a widely known method in which a small piece of a die bond sheet having the same dimensions as a semiconductor chip is prepared and mounted in advance on a lead frame, or attached to the back surface of each chip one by one. It has been. However, in this case, the work is very complicated and undesirable, and in addition, a minute shift may occur when a small piece of the die bond sheet is attached to the lead frame or the back surface of the chip, which is desirable for these reasons. It's not a method.
Therefore, recently, after grinding the back side of the semiconductor wafer without the circuit pattern until a predetermined thickness is obtained in the back grinding process (by applying a stress relief process if necessary), a die bond sheet is placed on the back side. There has been proposed a method in which a semiconductor wafer and a die bond sheet are simultaneously fully cut with a wafer dicing apparatus or the like by bonding, fixing and fixing this to a dicing tape.

In this method, it is possible to create a state in which the dimensions of the diced chip and the small piece of the die-bonding sheet are completely the same, and the two are bonded together without any deviation. In this case, as shown in FIG. 10, when the die bond sheet 12 is bonded to the back surface side of the semiconductor wafer 9, the circuit pattern 8 surface of the semiconductor wafer 9 is faced down while being bonded by the bonding roll 11 or the like. Since it is necessary to bond, the circuit pattern 8 may be damaged by the bonding pressure of the bonding roll 11, and thus the circuit pattern 8 surface needs to be protected. Then, if the die bond sheet 12 is bonded to the back surface side of the semiconductor wafer 9 in a state where the surface protective tape 15 having the pressure-sensitive adhesive layer 13 formed on the base film 14 is not peeled off and bonded as it is after the back grinding process, Since the surface protection tape 15 serves to protect the circuit pattern 8, this method is generally used in this method.
In this case, the die bond sheet 12 needs to be bonded in a heated state for adhesion to the semiconductor wafer. Generally, the surface protection tape 15 of the semiconductor wafer 9 is bonded. A method is adopted in which the applied surface is placed on the heating adsorption table 10 with the surface facing down and fixed by suction, and the die bond sheet 12 is bonded to the entire back surface on the upper side by the bonding roll 11. Since the semiconductor wafer itself is in a high temperature state on the heating adsorption platform 10, the die bond sheet is bonded in that state, and thus the adhesion to the semiconductor wafer is good.

  However, since the surface protection tape 15 is directly brought into contact with the heating adsorption table 10 and heated at the time of pasting, the surface protection tape 15 applied to this method is required to have heat resistance. Specifically, the base film 14 of the surface protective tape 15 is directly contacted and heated by the heating adsorption table. At this time, the base film 14 undergoes thermal shrinkage, so that the surface protective tape 15 The force which warps the semiconductor wafer 9 works to the bonding surface side. As a result, when the warping force is greater than or equal to the adsorption force by the heating adsorption table, there arises a problem that the wafer is detached from the heating adsorption table. Moreover, even if it does not come off from the suction table, the wafer is vigorously warped at the moment when the suction is released as shown in FIG. 11 after the die bond sheet is bonded, so that the wafer is damaged or not damaged by the impact. However, since the warp is maintained in a state where the warp is generated, there arises a problem that handling property is remarkably deteriorated in a subsequent process.

Examples of the surface protection tape 15 used in such a process include those shown in the following documents 1 and 2. These basically prevent softening by heating by using a high melting point film as a base film. That is, examples of the base film specifically mentioned in the above two proposals include polyesters such as polyethylene terephthalate and polybutylene terephthalate, nylon (registered trademark), polyimide, polyether ether ketone, and the like. is there. Since these films have a high melting point, there is no problem even at a heating temperature of about 180 ° C. in terms of preventing thermal softening.
However, these surface protection tapes do not prevent wafer warp or the like due to thermal shrinkage of the base film, and are all insufficient in this respect.

In particular, these films that form the base layer of the above-described surface protection tape are heated and stretched after film formation. This causes relaxation during heating and causes thermal shrinkage, resulting in very large wafer warping. Result. In addition, even if these films are not stretched, because, for example, molding distortion has occurred at the time of molding by the T-die method or the inflation method, depending on the degree, this also heat shrinks when heated, This results in a large warp.
JP 2002-246345 A, JP 2003-176464 A

  Therefore, the object of the present invention is that the wafer warp caused by the behavior of the base material layer during heating is small, the heat resistance is excellent, the adhesion to the heating adsorption table is small, the pressure is flexible, and sufficient pressure absorption is possible. An object of the present invention is to provide a surface protection tape that hardly generates and has a good wafer finishing thickness accuracy after grinding, and a method of manufacturing a semiconductor chip using the surface protection tape.

The above object of the present invention is achieved by the following means.
That is, the present invention
(1) When bonding to the circuit pattern surface of a semiconductor wafer, grinding the surface without the circuit pattern of the semiconductor wafer, and then heating the surface with the tape bonded to the heat absorption table a surface protection tape of the circuit surface of a semiconductor wafer used, Ri base layer of the tape the name by using the non-woven fabric and / or fabric, the crosslinked layer is provided on the back side of the substrate layer Semiconductor wafer surface protection tape, characterized by
(2) The semiconductor wafer surface protective tape according to (1 ), wherein the crosslinked layer is cured with radiation ,
(3) The semiconductor wafer surface protection tape according to (1) or (2 ), wherein the thickness of the cross-linked layer is 20 μm or more ,
(4) The semiconductor wafer surface protective tape according to any one of (1) to (3), wherein the nonwoven fabric and / or the woven fabric is made of a polyester resin and / or a nylon resin .
(5) The semiconductor wafer surface protection tape according to any one of (1) to (4) is bonded to the circuit pattern surface of the semiconductor wafer with the adhesive layer of the tape, and the semiconductor wafer has no circuit pattern. After the surface is ground, the die-bonded sheet is bonded to the ground surface without a circuit pattern in a state where the surface to which the tape is bonded is adsorbed to the heating adsorption table, a semiconductor chip manufacturing method,
Is to provide.

The surface protection tape of the present invention warps a semiconductor wafer greatly when a die bond sheet is bonded without causing the base material layer of the surface protection tape to be in direct contact with the heating adsorption table and being heated and causing heat shrinkage. There is nothing. Moreover, it can prevent that a base material layer adheres to a heating adsorption stand.
Furthermore, since the thickness of the base material layer of the surface protection tape is uniform and smooth during grinding of the back surface of the semiconductor wafer, the generation of dimples is prevented, and the precision of the finished thickness of the wafer after grinding is extremely excellent.
Therefore, the semiconductor chip manufacturing method using this surface protection tape enables the manufacture of an excellent quality semiconductor chip.

Hereinafter, with reference to the drawings, preferred embodiments of the surface protective tape according to the present invention will be described.
The surface protection tape of the present invention is a surface protection tape 3 in which an adhesive layer 1 is formed on the surface of a base material layer 2 as shown in FIG.

The base material layer 2 is preferably composed of a nonwoven fabric and / or a woven fabric, and is basically composed of natural fibers or synthetic resin fibers. In the case of a non-woven fabric, individual fibers are stacked in a plane, and only the contact points between the fibers are fused to form a film-like structure in which the non-fused portion has a breathable gap, Further, in the case of a woven fabric, as shown in an enlarged view in FIG. 2, the fibers 4 are woven in the vertical and horizontal directions and have a film shape having pores 5.
This film-like base material layer is made of natural fiber or resin fiber, unlike a film made by a conventional T-die method or inflation method, so that the layer has a breathable void. is there.

In the present invention, the base material layer has voids inside means that the nonwoven fabric or woven fabric used for the base material layer has air-permeable voids at least between the fibers and yarns constituting the voids. It means that the substrate layer has sufficient space to absorb heat shrinkage when the base material layer is heat-bonded.
In the process of forming the base material layer of the present invention into a film, there is no heat history such as heat stretching or molding distortion that causes heat shrinkage as described above. There is no problem that causes a very large wafer warpage at the time. When the fiber constituting the base material layer of the present invention is a resin fiber, some heat history is applied to the fiber in the process of forming it, but the effect is small because it is not a film process. . Furthermore, because of the structure, these base material layers have air-permeable voids between the fibers, and therefore have the effect of releasing the influence of shrinkage into the voids, which can be said to be an effective structure for reducing warpage.
In addition, the base material layer of this invention contains the nonwoven fabric and / or textile fabric which have a breathable space | gap, and may contain the film which has a ventilation hole in addition.

  The bonding temperature of the die bond sheet in the present invention is generally about 100 to 180 ° C. depending on the type, and the time required for bonding is about 3 minutes. At this time, if the base material layer 2 of the surface protection tape 3 does not have heat resistance sufficient to withstand the bonding temperature, the base material layer 2 in direct contact with the heating adsorption table is softened by heating, and as a result, heat adsorption The phenomenon of adhering to the table occurs. In particular, when a heating adsorption table is used as the heating adsorption table, if the base material layer 2 is softened by the heat of the heating adsorption table, the degree of adhesion increases due to the adsorption force of the heating adsorption table, resulting in strong adhesion. Become. As a result, even if the suction is released, the semiconductor wafer cannot be taken out from the heated suction table. Also, if this is forcibly peeled off, the wafer may be damaged by the impact.

  When the bonding temperature of the die bond sheet is around 100 ° C., there is no particular problem even if the base material layer is a polyolefin such as polyethylene, but when the bonding temperature reaches about 150 to 180 ° C., these materials soften and adhere to the adsorption table. Resulting in. In the case of a bonding temperature of about 150 to 180 ° C., the material is preferably a polyester type or nylon type, and there is no particular concern about softening due to heating at these heat resistance levels. Therefore, the base material layer of the present invention has no particular problem even if the fibers constituting the nonwoven fabric or the woven fabric are polyolefin-based when the die bond sheet bonding temperature is about 100 ° C, but the bonding temperature is about 150 to 180 ° C. In this case, it is desirable that the fiber material is a non-woven fabric or woven fabric of polyester resin or nylon resin.

The diameter of the fiber constituting the nonwoven fabric or woven fabric in the present invention is various and not particularly limited, but generally about 30 to 90 μm is preferable. Further, the thickness is not particularly limited, and generally a thickness of about 40 to 100 μm may be used.
On the other hand, depending on the type of this nonwoven fabric or woven fabric, the thickness accuracy as a base material layer may be slightly inferior to a film formed by a normal T-die method or an inflation method.
In the case of a non-woven fabric, it is possible to improve the thickness accuracy by prescribing the non-woven fabric and then applying heat press in the thickness direction. There may be a thickness variation of about 15 to 20 μm. Incidentally, since the hot press is only applied in the thickness direction, it is not a heat history that causes heat shrinkage due to heating in a subsequent process.

  In the case of a woven fabric, the overall thickness accuracy is very good, but there may be a step in the joint 4a between the fiber 4 and the fiber 4 as shown in FIG. In the case of woven fabrics, the fibers are woven while supplying the fibers wound around the bobbin-shaped jig. There is a break and it is necessary to join the fibers. In this case, generally, a method of connecting fibers and fiber ends, or a method of fusing is adopted, but there is a case where a step formed by them becomes about 20 μm depending on the fiber diameter. If the 20 μm step comes to the wafer bonding area, it is not preferable because the step on the circuit pattern surface may appear as a dimple, which is a phenomenon that the step on the circuit pattern surface is transferred to the ground surface on the back surface of the wafer.

Therefore, the present invention has an object to prevent the occurrence of dimples in such a case. It solved by covering the back side (meaning the surface on the opposite side to the surface with the adhesive layer 1) of the base material layer comprised of the nonwoven fabric and / or the woven fabric with a crosslinked layer. As the cross-linked layer, a radiation curable pressure-sensitive adhesive layer cured by radiation is preferable. In addition, a heat cross-linkable pressure-sensitive adhesive layer that forms a cross-linked structure by heating, or a main structure and a curing agent are mixed to form a cross-linked structure 2 There are liquid-mixing pressure-sensitive adhesive layers.
That is, as shown in FIG. 4, the surface protection tape 7 which is another aspect of the present invention comprises a non-woven fabric and / or a base material layer 2 and a pressure-sensitive adhesive layer 1 of the woven fabric, and a cross-linked layer such as radiation on the back side. It is set as the structure which provided the radiation-curing-type adhesive layer 6 hardened | cured by (4). It is possible to eliminate uneven thickness and smoothness by covering the step of the joint with a cross-linked layer, for example, a radiation curable adhesive layer cured with radiation, to eliminate poor thickness accuracy due to the above. It becomes.
Furthermore, the thickness of the radiation-curing pressure-sensitive adhesive layer 6 cured by radiation is 15 to 20 μm depending on the thickness variation of the nonwoven fabric as described above, and about 20 μm depending on the step that can be formed at the joint of the fabric. Therefore, in order to completely cover this, the thickness is required to be 20 μm or more, preferably 20 to 200 μm, and more preferably 25 to 100 μm. If the thickness is less than 20 μm, the variation cannot be completely covered. In particular, in the case of a woven fabric level difference, a level difference exists locally, so that it tends to occur as dimples, and if it exceeds 200 μm, there is a problem in terms of cost.

  In the case of the surface protective tape 7 having this configuration, first, a radiation curable pressure-sensitive adhesive is applied to one side of the nonwoven fabric and / or the base material layer 2 of the woven fabric, and the formed radiation curable pressure-sensitive adhesive layer 6 is irradiated with radiation. It is obtained by forming the pressure-sensitive adhesive layer 1 on the surface opposite to the radiation-curable pressure-sensitive adhesive layer 6 cured by radiation. As the order, after applying the adhesive to the obtained base material layer, the order of applying the radiation curable adhesive on the opposite surface and irradiating with radiation may be cured, but the adhesive is radiation curable. In this case, when the radiation curable pressure-sensitive adhesive is irradiated with radiation, the pressure-sensitive adhesive is also cured at the same time.

  The radiation curable pressure-sensitive adhesive layer 6 cured by radiation generally has a configuration in which a normal acrylic pressure-sensitive adhesive and a radiation polymerizable compound are mixed, or a configuration in which the radiation polymerizable compound alone is used. Of these, in the case of a radiation-polymerizable compound, a three-dimensional network structure is formed by irradiation with radiation, that is, a kind of cross-linked structure is formed. When the molecular structure is a crosslinked structure, it usually has no property of being plasticized even in a heated state, and therefore is not softened by heating. Therefore, it is not softened by the above-mentioned heating adsorption table. The radiation curable pressure-sensitive adhesive layer 6 cured by ordinary radiation does not soften at about 180 ° C., and is cured by radiation even if a nonwoven fabric or a polyolefin material is used as the material of the fabric. If it is the structure which provided the radiation curing type adhesive layer 6 in the back surface, even if the bonding temperature of a die-bonding sheet is 180 degreeC, it can be used without a problem.

  The radiation-curable pressure-sensitive adhesive layer 6 cured by radiation in the present invention is not particularly limited, and generally comprises a normal acrylic pressure-sensitive adhesive and a radiation polymerizable compound as main components. . Also, the pressure-sensitive adhesive layer 1 is not particularly limited, and an ordinary acrylic pressure-sensitive adhesive or the like can be applied. In the case of a radiation curable type, the pressure-sensitive adhesive layer and the radiation-polymerizable are the same as described above. A composition having a compound as a main component is applied. Specific examples of these acrylic pressure-sensitive adhesives and radiation-polymerizable compounds are as follows.

The acrylic pressure-sensitive adhesive contains a (meth) acrylic copolymer and a curing agent as components. The (meth) acrylic copolymer is, for example, a polymer having (meth) acrylic acid ester as a polymer constituent unit, and a (meth) acrylic polymer of (meth) acrylic acid ester copolymer, or (meta ) A copolymer of an acrylic ester and a functional monomer, and a mixture of these polymers. As the molecular weight of these polymers, those having a weight average molecular weight of about 500,000 to 1,000,000 are generally applied.
Moreover, a hardening | curing agent is used in order to make it react with the functional group which a (meth) acrylic-type copolymer has, and to adjust adhesive force and cohesion force. For example, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, 1,3-bis (N, N-diglycidylaminomethyl) toluene, 1,3-bis (N, N-diglycidylaminomethyl) ) Epoxy compounds having two or more epoxy groups in the molecule such as benzene, N, N, N, N'-tetraglycidyl-m-xylenediamine, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate , 1,3-xylylene diisocyanate, 1,4-xylene diisocyanate, diphenylmethane-4,4′-diisocyanate and the like, an isocyanate compound having two or more isocyanate groups in the molecule, tetramethylol-tri-β-aziridini Lupropionate, trimethylol-tri-β-aziridinylpropionate, Examples thereof include aziridine compounds having two or more aziridinyl groups in the molecule, such as dimethylolpropane-tri-β-aziridinylpropionate and trimethylolpropane-tri-β- (2-methylaziridine) propionate. .
What is necessary is just to adjust the addition amount of a hardening | curing agent according to desired adhesive force, Preferably it is 0.1-5.0 mass parts with respect to 100 mass parts of (meth) acrylic-type copolymers.

  The radiation curable pressure-sensitive adhesive generally comprises the above acrylic pressure-sensitive adhesive and a radiation polymerizable compound as main components. As the radiation-polymerizable compound, for example, a low molecular weight compound having at least two photopolymerizable carbon-carbon double bonds in a molecule that can be three-dimensionally reticulated by irradiation with ultraviolet rays is widely used. Specifically, trimethylol is used. Propane triacrylate, tetramethylol methane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4-butylene glycol diacrylate, 1,6 hexanediol diacrylate Polyethylene glycol diacrylate, oligoester acrylate, and the like are widely applicable.

In addition to the acrylate compounds as described above, urethane acrylate oligomers can also be used. The urethane acrylate oligomer includes a polyol compound such as a polyester type or a polyether type, and a polyvalent isocyanate compound (for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diene). A terminal isocyanate urethane prepolymer obtained by reacting isocyanate, 1,4-xylylene diisocyanate, diphenylmethane 4,4-diisocyanate, etc., with an acrylate or methacrylate having a hydroxyl group (for example, 2-hydroxyethyl) Acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, polyethylene glycol acrylate, polyethylene glycol methacrylate, etc.) Obtained by the reaction.
As a compounding ratio of the acrylic pressure-sensitive adhesive and the radiation-polymerizable compound in the radiation-curable pressure-sensitive adhesive, the radiation-polymerizable compound is 50 to 200 parts by weight, preferably 50 to 150 parts by weight with respect to 100 parts by weight of the acrylic pressure-sensitive adhesive. It is desirable to blend in the range of parts. In the case of this blending ratio range, the adhesive strength of the pressure-sensitive adhesive layer is greatly reduced after radiation irradiation.
Furthermore, the radiation-curable pressure-sensitive adhesive can be made into a radiation-polymerizable acrylic ester copolymer instead of blending the radiation-polymerizable compound with the acrylic pressure-sensitive adhesive as described above. is there.

  When the adhesive is polymerized by radiation, a photopolymerization initiator such as isopropyl benzoin ether, isobutyl benzoin ether, benzophenone, Michler's ketone, chlorothioxanthone, benzyl methyl ketal, α-hydroxycyclohexyl phenyl ketone, 2-hydroxymethyl Phenylpropane or the like can be used in combination. By adding at least one of these to the pressure-sensitive adhesive, the polymerization reaction can proceed efficiently. In addition, the radiation here refers to light rays such as ultraviolet rays or ionizing radiation such as electron beams.

Next, a preferred embodiment of a semiconductor chip manufacturing method using the surface protection tape of the present invention will be described.
In the semiconductor chip manufacturing method of the present invention, first, as shown in FIG. 5, the adhesive layer 1 of the surface protection tape 3 of the present invention shown in FIG. Like this, this surface protection tape is bonded. Next, as shown in FIG. 6, the surface side of the semiconductor wafer 9 without the circuit pattern 8 is ground until the thickness of the semiconductor wafer 9 becomes a predetermined thickness, for example, 50 to 200 μm. Thereafter, as shown in FIGS. 7 and 8, the surface of the surface protection tape 3 is placed on the heating adsorption table 10 with the surface bonded down, and in that state, the surface protection tape 3 is applied to the ground surface without the circuit pattern 8. It consists of the process of bonding the die-bonding sheet 12 using the combination roll 11.
In these steps, as described above, the back side of the base material layer 2 of the surface protective tape 3 is directly brought into contact with the high-temperature heating adsorption table 10 and heated during bonding. However, as described above, the surface protection tape 3 of the present invention has the base material layer 2 that does not heat soften even when heated, and the base material layer 2 adheres to the heat suction base 10 by the heat of the heat suction base. Such a problem does not occur, and the wafer does not warp.
Therefore, if the adsorption mechanism of the heating adsorption table 10 is opened as shown in FIG. 9, the semiconductor wafer with the surface protection tape and the die bond sheet can be easily taken out, and the heating adsorption table is hardly soiled.

Moreover, the surface protection tape 7 in which the bridge | crosslinking layer 6 was provided in the back side of the base material layer 2 shown in FIG. 4 can also be used for the manufacturing method of the semiconductor chip of this invention similarly to the above.
In this case, since the surface protective tape 7 has a uniform thickness and is smoothed, the accuracy of the thickness of the semiconductor wafer is particularly high, and the occurrence of dimples can be prevented.

EXAMPLES Next, although this invention is demonstrated further in detail based on an Example , a reference example, and a comparative example, this invention is not limited to a following example.

[ Reference Examples 1 to 6 ] and [Comparative Examples 1 and 2]
As shown in Table 1, the following “acrylic pressure-sensitive adhesive a” or “ultraviolet curable pressure-sensitive adhesive B” of each display was applied to one side of the base layer with a thickness of 30 μm, and the structure shown in FIG. Each surface protection tape was produced.
[Examples 1 , 2 , 3 ]
As shown in Table 1, the following ultraviolet curable pressure sensitive adhesive A was applied to one side of the base material layer to a thickness of 20 μm, and the ultraviolet curable pressure sensitive adhesive A was irradiated with ultraviolet rays and cured. Furthermore, the ultraviolet curable pressure sensitive adhesive B was applied in a thickness of 30 μm to the surface opposite to the surface provided with the ultraviolet curable pressure sensitive adhesive A cured by the ultraviolet light of the base material layer, and each of the structures shown in FIG. A surface protection tape was prepared.

Nonwoven fabrics, woven fabrics and films listed in Table 1 used as the base material layer are as follows.
(1) “TNo. 180” (trade name, manufactured by Nippon Special Textile Co., Ltd.)
A polyester fiber woven fabric, a fiber-fiber joint portion and a fiber-fiber joint portion (step 17 μm) were collected and used in the examples. For Reference Example 5 and Example 2 (in the table, described as having a seam) including the fiber and fiber seam, the seam is bonded so that the seam is within the wafer surface at the time of wafer bonding described later. Combined.
(2) "NNo180" (trade name, manufactured by Nippon Special Textile Co., Ltd.)
Nylon fiber woven fabric was used where the fiber and fiber were seamless.
(3) “PE150” (trade name, manufactured by Nippon Special Textile Co., Ltd.)
A polyethylene fiber fabric was used where there was no fiber-to-fiber joint.
(4) “Bonden” (trade name, manufactured by Kureha Tech Co., Ltd.)
Non-woven fabric (thermal bond type: thickness accuracy ± 4 μm) subjected to hot pressing of polyester fiber.
(5) “DYNAC” (trade name, manufactured by Kureha Tech Co., Ltd.)
It is a nonwoven fabric of polyester fiber (spunbond type: thickness accuracy ± 18 μm).
(6) “ACRLIFT WD-210” (trade name, manufactured by Sumitomo Chemical Co., Ltd.)
It is an ethylene-methyl methacrylate copolymer (EMMA) film.
(7) "Ester film E5100-100" (trade name, manufactured by Toyobo Co., Ltd.)
It is a polyester film.

The composition of the used ultraviolet curable adhesive A, ultraviolet curable adhesive B, and acrylic adhesive a is as follows.
(UV curable adhesive A)
Acrylate ester copolymer 100 parts by weight Curing agent ("Coronate L" (trade name, manufactured by Nippon Polyurethane Co., Ltd.) 2 parts by weight Urethane acrylate oligomer 150 parts by weight Photopolymerization initiator ("Irgacure 184" (trade name) ), Made by Nippon Ciba-Geigy
2 parts by mass (UV curable adhesive B)
Acrylic ester copolymer 100 parts by weight Curing agent ("Coronate L" (trade name, manufactured by Nippon Polyurethane Co., Ltd.) 2 parts by weight Urethane acrylate oligomer 100 parts by weight Photopolymerization initiator ("Irgacure 184" (trade name) ), Made by Nippon Ciba-Geigy
2 parts by mass (acrylic adhesive a)
Acrylic ester copolymer 100 parts by mass Curing agent ("Coronate L" (trade name, manufactured by Nippon Polyurethane Co., Ltd.) 2 parts by mass

(Wafer backside grinding)
The heat-resistant surface protective tapes of Examples , Reference Examples and Comparative Examples obtained by the above methods were bonded to the surface of an 8-inch silicon wafer having a thickness of 650 μm, and the disco grinder “DFG8560” (trade name) was attached. Then, the wafer back surface was ground so that the final finish thickness was 100 μm with the surface roughness “# 2000”. Furthermore, after grinding, place the back side of the base material layer (if the UV curable pressure-sensitive adhesive layer A cured by ultraviolet rays is on the back side) on the suction platform with a heating mechanism set to 150 ° C. “DF-470” (trade name, manufactured by Hitachi Chemical Co., Ltd.) was bonded as a die bond sheet to the back surface of the wafer that had been placed on the side and ground in an adsorbed and fixed state. After pasting, the adsorption of the heating adsorption table was released, and the wafer with the surface protective tape and the die bond sheet was taken out.

(Evaluation of die bond sheet bonding)
The above steps were carried out, the following points were evaluated, and the results are shown in Table 1.
(1) Generation of dimples It was visually observed whether or not dimples were generated on the ground surface of the wafer after grinding the wafer back surface.
(2) Wafer Finish Thickness Accuracy The TTV of the wafer thickness after grinding the wafer back surface (target value: 100 μm thickness) was measured with an ADE fully compatible wafercom 200XJ.
(3) Wafer warpage after die bond sheet bonding After bonding the die bond sheet “DF-470” using a bonding roll on an adsorption table with a heating mechanism set to 150 ° C., and releasing the adsorption, The wafer with the surface protection tape and the die bond sheet was taken out. After taking out, it left still on the horizontal base and measured the maximum value of the curvature of the wafer from the horizontal base.
(4) Presence / absence of adhesion to the heating adsorption table After bonding the die bond sheet “DF-470” using a bonding roll on an adsorption table with a heating mechanism set to 150 ° C. and releasing the adsorption, the surface The wafer with the protective tape and the die bond sheet was taken out. At that time, it was visually observed whether or not the surface protective tape was adhered to the adsorption table by heat softening.

The evaluation results of each example , reference example and comparative example are described below.
( Reference Example 1) Since the base material layer is a non-woven fabric made of polyester fibers having sufficient air-permeable gaps, and the thickness accuracy is controlled by further applying heat press, the amount of wafer warpage after die bonding sheet heating and bonding is small. Since it was a polyester, it was not softened by heating, and there was no adhesion to the heating adsorption table. Further, no dimples were generated due to wafer back grinding, and TTV was relatively good.
( Reference Example 2) Since the base material layer was a woven fabric made of polyester fibers having a sufficient air-permeable gap, no dimples were generated by wafer back surface grinding, and TTV was good. Further, the amount of warpage of the wafer after die bonding sheet heating was small, and since it was polyester, there was no heat softening and there was no adhesion to the heating adsorption table.
( Reference Example 3) Since the base material layer was a woven fabric made of nylon fibers having sufficient air-permeable gaps, dimples were not generated due to wafer backside grinding, and TTV was good. Further, the amount of warpage of the wafer after heat bonding of the die bond sheet was small, and since it was nylon, there was no heat softening, and there was no adhesion to the heat adsorption table.

( Reference Example 4) The base material layer is a non-woven fabric made of polyester fiber having a sufficient air-permeable gap, and the thickness accuracy is not good because it is a type that is not particularly subjected to treatment such as hot pressing (spun bond type). Some dimples were observed due to the backside grinding of the wafer, and the TTV was poor, but it was barely usable in some cases. Further, the amount of warpage of the wafer after die bonding sheet heating and bonding was small, and since it was polyester, there was no heat softening and there was no adhesion to the heating adsorption table.
(Example 1 ) The base material layer is a non-woven fabric made of polyester fibers having sufficient air-permeable gaps, and is a type that is not particularly subjected to a treatment such as hot pressing (spunbond type), but the back side is UV-rayed. Since the cured ultraviolet curable pressure-sensitive adhesive layer A is provided, dimples are not generated by grinding the back surface of the wafer, and TTV is relatively good. Further, the amount of warpage of the wafer after die bonding sheet heating was small, and the UV curable pressure-sensitive adhesive layer A cured with ultraviolet rays was not softened by heating, and there was no adhesion to the heating adsorption table.
( Reference Example 5 ) Although the base material layer is a woven fabric made of polyester fiber having a sufficient air-permeable gap, it includes a fiber-fiber joint (step 17 μm). The outbreak was seen. Moreover, although TTV was also somewhat bad by this, it was a level which can be used depending on the case. The amount of warpage of the wafer after heat bonding of the die bond sheet was small, and since it was a polyester, there was no heat softening and there was no adhesion to the heat adsorption table.

(Example 2 ) Although the base material layer is a woven fabric made of polyester fiber, it includes a fiber-to-fiber joint (step 17 μm), but an ultraviolet curable pressure-sensitive adhesive layer A cured by ultraviolet rays is provided on the back side. As a result, the generation of dimples due to wafer back surface grinding was not observed even at the joint. TTV was also good. Further, the amount of warpage of the wafer after heat bonding of the die bond sheet was small, and since it was an ultraviolet curable pressure-sensitive adhesive layer A cured with ultraviolet rays, there was no heat softening and there was no adhesion to the heating adsorption table.
( Reference Example 6 ) Since the base material layer was a woven fabric made of polyethylene fibers, no dimples were generated by grinding the wafer back surface, and TTV was good. However, since it is polyethylene, it was slightly adhered to the adsorption table by heat softening during the heat bonding of the die bond sheet. After the adhered sample was peeled off and taken out, the amount of warpage of the wafer was measured and found to be small and good.
(Example 3 ) Although the base material layer is a woven fabric made of polyethylene fiber, since the ultraviolet curable pressure-sensitive adhesive layer A cured by ultraviolet rays is provided on the back surface side, generation of dimples due to wafer back surface grinding is caused. There was no TTV. Moreover, the amount of wafer warpage after heat bonding of the die bond sheet was small, and there was no practical problem. Since it was an ultraviolet curable pressure-sensitive adhesive layer A cured with ultraviolet rays, it was not heated and softened, and there was no adhesion to the heated adsorption table.

(Comparative Example 1) Since the base film was a film made of EMMA and having no air-permeable gaps, no dimple was observed due to wafer backside grinding, but the TTV was slightly worse. Moreover, since it was EMME, it adhere | attached firmly to the adsorption stand by heat softening at the time of die bonding sheet | seat heat bonding. After the bonded sample was peeled off and taken out, the amount of warpage of the wafer was measured and found to be very large.
(Comparative Example 2) Since the base film was a polyester film having no air-permeable voids, no dimples were observed due to wafer backside grinding, and TTV was good. However, the amount of wafer warpage after heat bonding of the die bond sheet was very large, and the wafer warped off from the suction table before the suction of the suction table was released. Adhesion to the heated adsorption table was not observed because it was polyester.

It is sectional drawing of the surface protection tape of this invention. It is an enlarged view which shows a textile fabric. It is an enlarged view which shows the textile fabric which has a seam part of a fiber and a fiber. It is sectional drawing of the surface protection tape of the other aspect of this invention. It is sectional drawing which shows the state which bonded the surface protection tape on the circuit pattern surface of the semiconductor wafer. It is sectional drawing which shows the state after grinding the surface side without a circuit pattern of a semiconductor wafer until it becomes predetermined thickness. It is sectional drawing which shows the state which mounted the semiconductor wafer on the heating adsorption stand with the surface by which the surface protection tape was bonded down. It is sectional drawing which shows the state which bonds a die-bonding sheet | seat with the bonding roller to the grinding | polishing surface side of a semiconductor wafer. It is sectional drawing which shows the state which took out the surface protection tape and the semiconductor wafer with a die-bonding sheet from the heating adsorption stand. It is sectional drawing of the prior art which shows the state which bonds a die-bonding sheet | seat with the bonding roller to the grinding | polishing surface side of a semiconductor wafer. It is sectional drawing of the prior art which shows the state which the curvature generate | occur | produced in the wafer when taking out the semiconductor wafer with a surface protection tape and a die-bonding sheet from a heating adsorption stand.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Adhesive layer 2 Base material layer 3 Surface protection tape 4 Fiber which forms woven fabric 4a Fiber-to-fiber joint in the woven fabric 5 Pore 6 Radiation curable pressure-sensitive adhesive layer 7 Surface protective tape 8 Circuit pattern 9 Semiconductor wafer 10 Heat absorption stand 11 Bonding roll 12 Die bond sheet 13 Adhesive layer 14 Base film 15 Surface protection tape

Claims (5)

It is used for bonding to the circuit pattern surface of the semiconductor wafer, grinding the surface without the circuit pattern of the semiconductor wafer, and then heating the surface to which the tape is bonded by adsorbing it to the heating adsorption table. a surface protection tape of the circuit surface of the semiconductor wafer, and wherein the Ri base layer of the tape the name by using the non-woven fabric and / or fabric, the cross-linking layer on the back side of the substrate layer is provided Semiconductor wafer surface protection tape. Semiconductor wafer surface protection tape of claim 1, wherein the crosslinked layer is one which is cured by radiation. Claim 1 or 2 semiconductor wafer surface protection tape, wherein the thickness of the crosslinked layer is 20μm or more. The semiconductor wafer surface protective tape according to any one of claims 1 to 3, wherein the nonwoven fabric and / or the woven fabric comprises a polyester resin and / or a nylon resin. The semiconductor wafer surface protective tape according to any one of claims 1 to 4 is bonded to the circuit pattern surface of the semiconductor wafer with the adhesive layer of the tape, and after grinding the surface without the circuit pattern of the semiconductor wafer, A method of manufacturing a semiconductor chip, comprising: bonding a die bond sheet to a ground surface side having no circuit pattern in a state where the surface to which the tape is bonded is adsorbed to a heating adsorption table.

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