JP2005225068A - Manufacturing method of semiconductive substrate film for dicing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a semiconductive substrate film for dicing to which excellent expansibility and characteristics not causing the occurrence of dicing refuse, wafer chipping and static electricity are imparted in a well-balanced state. <P>SOLUTION: A film A and a film B are laminated. A dry blend resin with a moisture content of 500-3,000 ppm, which is composed of 40-75 mass% of a PP or PE resin and 60-25 mass% of a hydrophilic PE or PP resin having a polyoxyalkylene chain block bond, is supplied to a full-flight gradual reducing depth type screw extruder (FF extruder) with a metering groove depth of 3.5-7.5 mm, a compression ratio of 1.5-2.5 and a barrel temperature of 145-235°C to be extruded from a T-die and cooled to 40-100°C to be taken off (film A). The PE resin is supplied to an FF extruder with a metering groove depth of 1.5-3.0 mm, a compression ratio of 2.5-3.5 and a barrel temperature of 150-210°C to be extruded from the T-die and cooled to 40-100°C to be taken off (film B). At least one PE resin is also laminated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a substrate film for semiconductive dicing effective for dicing a semiconductor wafer or the like into chips.

For example, a semiconductor wafer made in advance with a large area is diced (cut) into chips, and it is necessary to fix the wafer during dicing. A dicing board is used for this fixing and dicing.
The mount is basically composed of an adhesive layer for fixing the wafer and a resin layer (dicing base layer) for receiving a cut by a dicing cutter. As the resin layer, a polyolefin film or a polyvinyl chloride film is generally used. However, the polyvinyl chloride film is in a decline due to environmental problems.

A problem in dicing a semiconductor wafer (hereinafter simply referred to as a wafer) is, for example, chips from a dicing board (dicing waste) generated during dicing or wafer notches (in the industry, this is called chipping). ), Expansion (extensibility) of the mount after dicing, and static electricity generated when dicing or after dicing and picking up a cut wafer.
Concerning this static electricity, especially in the recent trend of gathering more information in smaller wafer chips, it has become a bigger issue.
In other words, this is because there is a high risk that the occurrence of static electricity leads to the destruction of information integrated on the wafer chip. There are many patent technologies that address these various problems, and many improved technologies have been published.
The wafer chipping problem is seen when the dicing mount, particularly its substrate layer, does not have the proper rigidity and is too low. In other words, the mount itself moves slightly with the dicer cutting operation, and as a result, the wafer cutting position shifts and appears as a notch.

For example, the following patent applications have been published as patent technologies for the purpose of improving chips and / or extensibility.
A film made of polyolefin resin such as polyethylene, ethylene / vinyl monomer copolymer, polypropylene, polymethylpentene or the like is irradiated with 1-8 Mrad electron beam or γ-ray, and an adhesive layer is laminated thereon (see, for example, Patent Document 1). ), A film made of a copolymer of methyl methacrylate containing ethylene as a main component and an adhesive layer laminated (for example, see Patent Document 2), 3 of ethylene and methacrylic acid and C3-C8 methacrylic acid alkyl ester It has been found that the extensibility of the base layer by the film made of the original copolymer with the adhesive layer laminated (for example, see Patent Document 3) and the polyolefin film is related to the inner surface retardation, together with the surface roughness of the layer. , This internal phase difference with a specific condition (this internal phase difference increases the extrusion temperature) To, without the draw, expression by quenching taking) (for example, a patent document 4 reference.) Or the like.
Japanese Patent Laid-Open No. 5-21234 JP-A-5-156214 Japanese Patent Laid-Open No. 7-230972 JP 2001-11207 A

On the other hand, for example, the following is disclosed as a patented technique for preventing the generation of static electricity.
Acrylic copolymerization of an acrylic amphoteric or cationic surfactant, a maleic anhydride-styrene anion, or a thermosetting antistatic agent between the base sheet and the adhesive layer made of polyethylene, polypropylene, etc. And a polyoxyethylene in 100 parts by weight of polypropylene (specifically, a blended polypropylene resin with a polyethylene-based resin) obtained by laminating an antistatic layer mixed with the above (for example, see Patent Documents 5 and 6). A film (copolymerized with 10 to 200 parts by weight) of a copolymer of a chain monomer and butadiene is mixed to form a base material (kneaded with a twin-screw kneader and then extruded with an extruder), and this is a radiation polymerizable adhesive. (For example, refer to Patent Document 7), a pressure-sensitive adhesive layer made of a radiation-polymerizable pressure-sensitive adhesive, and a peeling film on the pressure-sensitive adhesive layer. An adhesive sheet for semiconductor processing having antistatic properties obtained by layering, wherein the withstand voltage to the adhesive surface of the sheet when the peeling film is peeled is specified to be 200 V or less (for example, Patent Documents) 8).
In addition, the pressure-sensitive adhesive sheet for semiconductor processing described in Patent Document 8 is specifically a laminate in which the pressure-sensitive adhesive layer and the peeling film are laminated on a base film provided with antistatic properties. Examples of the base film include those obtained by kneading and molding anionic, cationic or nonionic surfactants generally known for resins such as polyethylene and polypropylene, and in Example 1, Also exemplified is a polymer type antistatic agent kneaded with a polyether / polyolefin block polymer (perestat 300), which is different from a surfactant. Specifically, in Example 1, 15 parts by weight of the polymer type antistatic agent was kneaded with 100 parts by weight of polypropylene with a twin-screw kneading extruder, and then extruded with an extruder to obtain a sheet having a thickness of 150 μm. A radiation-polymerizable pressure-sensitive adhesive layer and a release film are laminated thereon to obtain a semiconductor processing pressure-sensitive adhesive sheet. Then, after aging at room temperature for 7 days or more, the withstand voltage when the peeling film was peeled off was measured to obtain 80V.
Japanese Patent Laid-Open No. 9-190990 JP 2000-178516 A JP 2003-147302 A Japanese Patent Laid-Open No. 2003-282489

  The present invention provides a dicing substrate film for dicing that is free from the occurrence of dicing debris or wafer chipping as described above, has excellent expandability, and does not lead to destruction of integrated information in the wafer chip based on generation of static electricity. As a result of earnest examination about the method, it has been achieved.

That is, the present invention is characterized by a method for producing a semiconductive dicing substrate film in which the semiconductive film A and the film B obtained by the following method are coextruded.
<Semiconductive film A>
A blend resin of 40 to 75% by mass of a polypropylene resin or polyethylene resin and a hydrophilic polyethylene resin or a hydrophilic polypropylene resin in which a polyoxyalkylene chain is block-bonded to a polyethylene chain or polypropylene chain of 60 to 25% by mass. The moisture content of the blended resin is adjusted to 500 to 3000 ppm, and this is adjusted to a groove depth of 3.5 to 7.5 mm, a compression ratio of 1.5 to 2.5, and a blend resin temperature of 145 to 235. Supplied to a full-flight gradual decrease deep screw extruder that has been adjusted to gradually increase in temperature within the range of ℃, extruded in a film form from a T-die controlled at a constant temperature within 210-230 ℃, and cooled at 40-100 ℃ The film A by the method
<Film B>
Full-flight gradual depth type in which a polyethylene resin is gradually increased and adjusted in the resin temperature range of 150 to 210 ° C. with a groove depth of 1.5 to 3.0 mm and a compression ratio of 2.5 to 3.5 mm. The film B obtained by feeding to a screw extruder, extruding in a film form from a T die controlled at a constant temperature of 210 to 230 ° C., cooling at 40 to 100 ° C., and taking it out.

Also, a method for producing a substrate film for semiconductive dicing in which semiconductive films A, B and B1 obtained by the following method are coextruded and laminated in the order of the film B / the film A / the film B1. Also features.
<Semiconductive film A>
A blend resin of 40 to 75% by mass of a polypropylene resin or polyethylene resin and a hydrophilic polyethylene resin or a hydrophilic polypropylene resin in which a polyoxyalkylene chain is block-bonded to a polyethylene chain or polypropylene chain of 60 to 25% by mass. The moisture content of the blend resin is adjusted to 500 to 3000 ppm, and this is adjusted to a groove depth of 3.5 to 7.5 mm, a compression ratio of 1.5 to 2.5, and the blend resin temperature of 145 to 235. Supplied to a full-flight gradual decrease deep screw extruder that has been adjusted to gradually increase in temperature within the range of ℃, extruded in a film form from a T-die controlled at a constant temperature within 210-230 ℃, and cooled at 40-100 ℃ The film A by the method
<Film B and Film B1>
Full-flight gradual depth type in which a polyethylene resin is gradually increased and adjusted in the resin temperature range of 150 to 210 ° C. with a groove depth of 1.5 to 3.0 mm and a compression ratio of 2.5 to 3.5 mm. The film B and the film B1 by a method of feeding to a screw extruder, extruding in a film form from a T-die controlled at a constant temperature of 210 to 230 ° C, cooling at 40 to 100 ° C, and taking it out.

The semiconductive dicing substrate film has a volume resistivity of 10 ⁹ to 10 ¹² Ω · cm when a DC voltage of 500 V is applied.

  The present invention, which is configured as described above, has the following effects.

  When used as a dicing mount for cutting wafers, etc., there is no occurrence of chips or wafer chipping based on dicing, film expansion after dicing is performed uniformly, and there is no static electricity that tends to occur in wafer pick-up. A substrate film for dicing which is balanced over all of these can be obtained.

  Further, the dicing mount using the substrate film for dicing is a dicing support (a vertical mechanism is used as a base for placing a dicing tape in tension and fixing a wafer or the like on the adhesive surface above to cut) As a result, it is easy to perform an expansion operation and to prevent necking that easily occurs at the edge portion of the cradle.

First, the substrate film for dicing (hereinafter referred to as “D substrate film”) according to the production method of the present invention is composed of two layers of semiconductive film A (hereinafter referred to as layer A) / film B (hereinafter referred to as layer B) or layer B / layer A. / The film B1 (hereinafter referred to as layer B1) consists of three layers, and the resin of layer A that is common to both layers is as follows.
A hydrophilic polyethylene resin (hereinafter referred to as a hydrophilic PE resin) or a hydrophilic polypropylene resin (hereinafter referred to as a hydrophilic PP resin) in which a polyethylene chain or a polyoxyalkylene chain is block-bonded to a polypropylene resin or a polypropylene resin. Resin). This is because the blended resin is used as the central layer of the D-base film to cause the central action of the above characteristics. In other words, this layer A acts to further improve the wafer chipping, chips and expandability of the polypropylene resin film or polyethylene resin film, and to provide new characteristics for suppressing static electricity generation, which is a serious problem.

Although it is the said hydrophilic PE resin or hydrophilic PP resin, this is as follows in general.
First, a polyolefin chain, preferably a polyethylene chain or a polypropylene chain, is bonded as a block to a polyoxyalkylene chain. This bond is mediated by an ester group, an amide group, an ether group, a urethane group, etc., but it is advantageous to use an ester group or an ether group, for example, in terms of expression of blendability or semiconductivity. . This polyethylene chain or polypropylene chain is bound by a block, so that compatibility with the blended polyethylene resin (hereinafter referred to as bPE resin) or polypropylene resin (hereinafter referred to as bPP resin) is appropriately obtained. This leads to the absence of a bleed-out phenomenon as seen in other surfactants described above.
In addition, combined use of the above-described conventionally known surfactants is not preferable because there is a high risk of bleeding out even if the amount added is small.

  In addition, since the polyoxyalkylene chain is bonded by a block, it leads to a higher static elimination action and an elimination of static electricity accumulation. Therefore, for example, if these chains are low molecular weight units and the bonds thereof are random, the neutralization effect tends to decrease with a decrease in suitable compatibility, which is not preferable.

  The hydrophilic PE resin or hydrophilic PP resin is nonionic. This is because when this resin has an anionic property or a cationic property, any metal ions can easily enter and there is no danger of adhering to a wafer or the like.

The polyethylene chain or the polypropylene chain has a high molecular weight as described above, but the molecular weight is smaller than a high molecular weight range (for example, 10,000 or more) generally called a polymer. For example, it is about 1200 to 6000. In this molecular weight range, in order to block-bond polyethylene or polypropylene to the polyoxyalkylene chain, the acid modification reaction of polyethylene or polypropylene, which is performed in the previous step, has a molecular weight of about 1200 to 6000 polyethylene or polypropylene. It depends on what is easy to do.
The molecular weight of one polyoxyalkylene chain is preferably about 1000 to 15000 in terms of heat resistance and acid modification reaction (with this polyethylene or polypropylene).
Although this polyoxyalkylene chain has semiconductivity, this volume resistivity is about 10 ⁵ to 10 ¹⁰ Ω · cm, and by being in this range, depending on the blend ratio and production method described later, For example, it is the basis for obtaining a D substrate film having a volume resistivity (hereinafter referred to as ρv) of 10 ⁹ to 10 ¹² Ω · cm.

  The manufacturing method of the hydrophilic PE resin or the hydrophilic PP resin itself is, for example, that the polyethylene or polypropylene having the above molecular weight is acid-modified and reacted with the polyalkylene glycol. Is described in, for example, Japanese Patent Application Laid-Open No. 2001-278985 or Japanese Patent Application Laid-Open No. 2003-48990, and is omitted.

And bPE resin or bPP resin blended with hydrophilic PE resin or hydrophilic PP resin has the following contents.
Both bPE resin and bPP resin are generally known polyethylene or polypropylene single polymer, copolymers of ethylene or propylene as main components (generally 90 mol% or more) and other olefin monomers or vinyl monomers, or two or more of these Blend resin is mentioned.

  Specifically, the bPE resin is a copolymer of a low density PE resin (LDPE), a high density PE resin (HDPE), a linear low density PE resin (L-LDPE), ethylene (meth) acrylic acid or an ester thereof. Can be illustrated. Among these, the HDPE or the copolymer is preferable.

  On the other hand, in bPP resin, for example, a propylene homopolymer obtained by a conventional catalyst or a metallocene catalyst, a (random) copolymerized propylene resin obtained by copolymerizing propylene with ethylene or further 1-butene, a highly crystalline polypropylene resin (for example, propylene homopolymer) And a low crystalline polypropylene resin (for example, copolymer propylene resin). In the case of this bPP resin, a propylene resin or a blend resin of a highly crystalline polypropylene resin and a low crystalline polypropylene resin or a generally known polyolefin-based or polystyrene-based thermoplastic elastomer and propylene alone rather than a propylene-only resin It is desirable to be a blended bPP resin with a resin.

  However, the bPE resin or bPP resin is not simply a blend of hydrophilic PE resin or hydrophilic PP resin. Conditions that can solve the above-mentioned problem very effectively in a well-balanced manner are set only by the following blend ratio range.

That is, the blend ratio is 40 to 75% by mass for bPE resin or bPP resin, preferably 50 to 70% by mass, 60 to 25% by mass for hydrophilic PE resin or hydrophilic PP resin, and preferably 50 to 30% by mass. It is. This range is specified for the following reason.
When hydrophilic PE resin or hydrophilic PP resin is blended with bPE resin or bPP resin, as the blending amount increases, chipping, chipping, expansion of defects found in the case of bPE resin alone or bPP resin alone. The point of static electricity removal by electricity or static elimination will be improved. However, when the blend amount is too large, not only does the support for improving the expandability stop, but it becomes too hard to use because it is out of the range of the proper film rigidity. Furthermore, the moldability as the layer A also deteriorates. The boundary between this area of improvement and the beginning of the deterioration trend is 60% by mass. That is, this 60% by mass is the maximum limit amount that balances chipping, expandability, static electricity removal, proper rigidity and layer formability.
On the other hand, when the amount is less than 25% by mass, the chip suppressing effect is reduced, the supporting effect is not exerted on the extensibility, and at least the necessary semiconductivity (that is, ρv10 ¹² Ω · cm) is obtained. This means that only a D substrate film that cannot handle static electricity can be obtained.
The expandability here is a necking phenomenon that occurs at the edge portion of the member, especially when the dicing mount is expanded by raising the dicing stand, and as a result, the entire uniform expansion is lost.

Further, the blend ratio of the hydrophilic PE resin or the hydrophilic PP resin in the case of using the bPE resin and the bPP resin is as described above in common, but each has a more preferable range. This is illustrated as follows.
First, bPE resin is bPE resin 50-70 mass% and hydrophilic PE resin 50-30 mass%, bPP resin is 55-65 mass% bPP resin and 45-35 mass% hydrophilic PP resin.

  The combination in the blend of bPE resin, bPP resin, hydrophilic PE resin, and hydrophilic PP resin described above is generally performed by a combination of bPE resin and hydrophilic PE resin, and bPP resin and hydrophilic PP resin. This may be a combination of bPE resin and hydrophilic PP resin, or bPP resin and hydrophilic PE resin. This latter combination is not better in terms of compatibility than the former combination, but the amount of the amphiphilic resin blended is less than that of the former. One of the effects is that, for example, a desired ρv is easily obtained even with a small blend amount. It is conceivable that there is a cause in the dispersion state of the amphiphilic resin (for example, it is easy to take a layered dispersion described later).

There are two types of the blended resin, one in which the two types are previously melt-kneaded and the other in two dry blends. Here, this dry blend is preferable. In other words, both raw materials (whether the raw material is in the form of powder or chips) can be simply mixed with a tumble mixer or the like, and once melted sufficiently using a twin-screw melt extruder or the like. It is not good to mix in. This is because, as will be described later, it is particularly easy to create a factor that inhibits the effective expression of ρv. If you want to melt and knead in advance, do not use a twin-screw extruder first, use a single-screw extruder, which is also possible under the conditions of a layer A film extruder, which will be described later. It is preferable to obtain a chip by extruding at as low a resin pressure as possible. That is, in the present invention, the preliminary melt kneading which is generally essential for two or more blends is not preferable.
Even when hydrophilic PE or hydrophilic PP resin is blended with the polyethylene-based resin of layer B and layer B1, dry blending is preferable for the above reason.

The resin of layer B or layer B and layer B1 laminated on layer A is a polyethylene resin, which is the same as that exemplified for the bPE resin used for the blending.
The layer B and the layer B1 may be the same or different.

And each said resin is shape | molded and laminated | stacked on a film under the following specific molding conditions, However, About this blend resin used by the layer A in this resin especially, the moisture content which this resin contains beforehand It is necessary to adjust so that it is in the range of 500 to 3000 ppm, preferably 800 to 2500 ppm. This moisture content is specified for the following reason.
This is because, among the above-mentioned characteristics provided by the layer A, it particularly affects the expression of ρv and the layer quality. That is, if it is less than 500 ppm, it is difficult to obtain the minimum required 10 ¹² Ω · cm, and if it exceeds 3000 ppm, irregularities (whether due to bubbles) occur in the layer.
In this moisture content adjustment, the moisture content is first measured at the time of blending, and if it is less than 500 ppm, it is left in a humidity adjustment room or the like to adjust the humidity. Conversely, when it exceeds 3000 ppm, it puts into a drier etc. and adjusts drying.
In addition, since the moisture content of the polyethylene-type resin of the layer B and the layer B1 is generally small, and there is no big influence like the layer A, the identification is not required dare. However, since hydrophilic PE or hydrophilic PP resin may be blended with this, in such a case, it is desirable to check in advance and confirm that it is at 500 to 3000 ppm.

First, the D substrate film by the two-layer film of layer A / layer B is manufactured under the following molding conditions. First, the layer B is laminated here for the following reason.
The layer is a layer necessary for imparting sufficiently satisfactory expandability. That is, the layer A itself does not have sufficient expandability (although improved with hydrophilic PE or hydrophilic PP resin). In order to bring this insufficient expandability to a sufficient expandability, it is necessary to laminate the layer B with this polyethylene resin. Originally, the polyethylene-based resin lacks expansibility as described above, but here, the laminating function reversely assists and enhances expansibility.

First, the semiconductive film A of the layer A is formed under the following conditions.
The blended resin having the moisture content adjusted is gradually increased in temperature within the range of the groove depth of the measuring section of 3.5 to 7.5 mm, the compression ratio of 1.5 to 2.5, and the blend resin temperature of 145 to 235 ° C. It is fed to a full-flight gradually decreasing deep screw extruder, and is extruded from a T-die controlled at a constant temperature of about 210 to 230 ° C., cooled at 40 to 100 ° C. and taken off.

And the film B of the layer B is shape | molded on the following conditions.
Full-flight gradual decrease by extruding the polyethylene-based resin with a groove depth of 1.5 to 3.0 mm and a compression ratio of 2.5 to 3.5, and gradually increasing the temperature in the range of the resin temperature of 150 to 210 ° C. It is fed to a deep screw extruder, extruded from a T die controlled at a constant temperature of 210 to 230 ° C. in a film form, cooled at 40 to 100 ° C. and taken off.

Each film obtained under the molding conditions is laminated to form a D base film. Examples of the laminating means include the following two methods.
Each film, one of which is obtained separately, is separately laminated by the dry lamination method. Two of them are laminated simultaneously using a two-layer T die, that is, a coextrusion method can be exemplified. Preference is given to the latter coextrusion method, since it is also productive, but a D-substrate film having improved scalability is obtained.
In the case of lamination by the coextrusion method, lamination is performed from two extruders through a T-die for two layers. Depending on the position of simultaneous merging (lamination), each of the feed block, multi-manifold, multi-slot There is a die. Either is fine.

In the above, in the formation of the semiconductive film A, the first selected extruder, that is, the extrusion screw, is a full flight gradually decreasing deep type screw (the height of the flight in full flight across the weighing unit, the compression unit, and the supply unit, That is, the groove depth is gradually reduced) (this includes continuous compression and rapid compression) (hereinafter referred to as FF screw). This type does not add excessive shear stress to the melt blend resin, and it is easy to obtain this type without particularly inhibiting the expression of ρv.
Generally, there are other torpedo type (no flight in the measuring section) and dull mage type (shallow groove multi-screw with a large helix angle in the measuring section), but these screws are all sent out by the measuring section. High shear stress is likely to be applied to the melt blended resin, which is particularly unsuitable because it results in inhibiting the expression of ρv.

  And even if it is the said FF screw, the measurement part groove depth is 3.5-7.5 mm, More preferably, it is 4.0-6.5 mm, The compression ratio is 1.5-2.5, More preferably, it is 1. Those of .6 to 2.0 are selected. This measuring portion groove depth is a factor particularly related to effective expression of ρv. In other words, if it goes to the shallower side, more shear stress will be added to the melt blend resin that is sent out, and if it goes to the deeper side, the discharge amount will try to increase. Pressure is applied. This shear stress particularly inhibits the effective expression of ρv, and the resin pressure more than necessary increases the residence time of the melt blend resin in the screw, and in particular disperses the hydrophilic PE resin component or hydrophilic PP resin component. Risk of decomposition. Therefore, the range in which the film can be safely formed without these dangers is 3.5 to 7.5 mm.

On the other hand, the compression ratio is also specified. In other words, the compression ratio is determined by the groove depth of the supply section if the measurement section groove depth is specified. Therefore, if the compression ratio is large, the groove depth of the supply section is deep, and if it is small, the groove depth is shallow.
This compression ratio is generally the apparent specific gravity of the feedstock (for example, it may be small if it is in the form of a chip, and it is increased if it is in the form of a powder), and whether or not melt kneading is necessary (large if necessary, if not Smaller). In the present invention, since it is better not to melt and knead as much as possible, the compression ratio range should be as small as possible, and the feedstock is preferably dry blended between chips, so the compression ratio is low. The range is good. The compression ratio in the present invention is 1.5 to 2.5 within a range found from the balance of both. That is, if it exceeds 2.5, melting and kneading more than necessary is promoted, and if it is less than 1.5, it is difficult to stably and continuously supply a quantitative amount (although it is a chip having a small apparent specific gravity).

  The size of the screw, that is, L / D, is appropriately selected depending on the desired extrusion amount (production amount). In the present invention, as described above, the effective expression of ρv is inhibited, or hydrophilic PE is used. There must be no risk of decomposition of the resin component or hydrophilic PP resin component. As L / D becomes larger, both of these risks are caused, so it is not desirable that L / D is too large. For example, it is better not to exceed about 35, preferably 30.

A further necessary condition is the blend resin temperature in the FF screw extruder.
It is necessary to adjust the temperature increase gradually in the range of 145 to 235 ° C., preferably 150 to 230 ° C., and set the blend resin temperature in the T die as a constant temperature within 210 to 230 ° C. (this The isotemperature is indirectly determined by the barrel temperature and the T-die temperature).
Here, the meaning of the gradual temperature increase adjustment of the blend resin temperature is that the temperature is adjusted continuously or stepwise from the supply part region to the compression part region to the measurement part region of the FF screw. This is because, in any of these regions, there is a risk of a sudden temperature rise exceeding 230 ° C. in that region, and this is prevented in advance. Therefore, it is ideal that the temperature increase is continuous.
If the maximum temperature of 235 ° C. is exceeded, the thermal degradation of the hydrophilic PE resin or PP resin in the blend resin is likely to occur, and the above-mentioned effects, in particular, effective expression of ρv, expandability, and wafer Improves chipping improvement. The lower limit of 145 ° C. is the preheating of the blended resin in the supply area, and if it is lower than this, the temperature in the compression area will be higher, and abrupt in this area (plasticization will take place). This is because heating is not preferable.

  Cooling of the film-like material discharged from the T die is 40 to 100 ° C, more preferably 60 to 90 ° C. Rapid cooling below 40 ° C. makes the film surface rough, and if it exceeds 100 ° C., the cooling efficiency is poor and the productivity is lowered. This cooling is preferably performed by contacting a temperature-controlled roller, but the arrangement position of this roller is determined in relation to the pulling-down rate. In the present invention, it is desirable that the pulling rate is about 5 to 10% so as not to increase. This is because the film-like material discharged from the T-die is soft and the neck-in is large. Therefore, this roll is preferably provided at a position where the range of 5 to 10% can be maintained.

In addition, there is resin pressure, but this is mainly changed so that the desired thickness and area (production amount) of the layer A can be changed, so that a resin pressure higher than necessary is not applied. To do. An unnecessarily high resin pressure tends to lead to an excessive shear stress and a temperature increase.
The resin pressure can also be adjusted by the degree of opening of the breaker plate with a screen mesh disposed between the T die and the tip of the FF screw. Considering the removal of dust, it is better to select and install as appropriate.

On the other hand, the molding conditions of the layer B film are basically film molding of polyethylene resin, and may be in the range of generally known or practiced extruders and molding conditions. However, since the polyethylene-based resin may be blended with hydrophilic PE or hydrophilic resin, and preferably two-layer coextrusion molding is performed, the condition of the layer A is as much as possible. It is desirable to be close to the molding conditions. The conditions set from this are: the groove depth of the measuring section is 1.5 to 3.0 mm, the compression ratio is 2.5 to 3.5, and the temperature is gradually increased and adjusted in the range of the resin temperature 150 to 210 ° C. Is supplied to a full-flight gradually decreasing deep screw extruder, extruded from a T-die controlled at a constant temperature within a temperature range of 210 to 230 ° C., cooled at 40 to 100 ° C., and taken off. In this case, the resin pressure is preferably kept at such a pressure that the thickness and area of the layer B film can be obtained, and the pulling rate is preferably in the same range as in the case of the layer A.

The D base film by the three-layer film of layer B / layer A / layer B1 is manufactured by the following molding conditions. Here, the reason for further layering of the layer B1 is as follows.
In the dicing mount using the two layers as the D base film, the layer A surface is in contact with the dicing receiving surface. However, it cannot be said that the lubricity of the surface of the layer A with respect to the receiving surface is sufficient. The slipperiness of this surface tends to worsen with increasing blend amount of hydrophilic PE resin or hydrophilic PP resin. Therefore, the layer B1 is used to make the slipperiness of the insufficient layer A surface excellent.
Further, the layer B1 also has an expansive assisting effect, and tends to be further improved. Furthermore, it is because it is easy to obtain D base film without the danger of film warping because both layers of layer A are made of the same polyethylene resin.
As described above, the B layer and the B1 layer have different main functions and effects, and therefore may be a combination of different types of resins corresponding thereto. For example, the B layer is a combination of copolymerized polyethylene with (meth) acrylic acid or its ester, and the B1 layer is LDPE.

The three-layer D-base film is formed under the same conditions as in the case of the two layers except that there are three layers and attention is paid to the stacking order. That is, it is preferably manufactured by three-layer coextrusion lamination. In this case, the blend resin extruder for the layer A, the resin extruder for the layer B and the layer B1, are a total of three resin extruders for the layer B. Using a table, the layer A is arranged so that the layer B and the layer B1 are positioned on both sides of the layer A, and co-extrusion is performed from the three-layer T die under the above-described extrusion conditions. A corresponding three-layer D substrate film is obtained. Here again, the layer B1 may be laminated under the same conditions as the layer B, or, like the layer B, hydrophilic PE or hydrophilic PP resin may be blended, and integral lamination is performed. Because it is easy.
The three-layer T die also includes feed block, multi-manifold, and multi-slot dies depending on the position of simultaneous merging (lamination). Either is fine.
Each D substrate film is preferably a T-die method, which cannot be manufactured by an inflation method.
The resins used for the layer A, the layer B, and the layer B1 may be added with a small amount of generally known olefin resin additives (for example, antioxidants, weathering agents, etc.).

The layers B and B1 made of the polyethylene resin may be basically an electrically insulating layer, that is, a layer in which a hydrophilic PE or hydrophilic PP resin is not blended. However, especially when the amount to be blended with the layer A is small, when the layer A is thin, or when the layer B and / or the layer B1 is thick and ρv10 ¹² Ω · cm is difficult to obtain. It is also possible to blend within an allowable range so that the ρv of this layer A is added and expressed. The meaning within the allowable range of the two resin blends is an amount that does not adversely affect the expandability by the layer B and the slipperiness by the layer B1, and the amount is, for example, 20% by mass or less, preferably 15% by mass. A small amount of 3% by mass or less is preferable.

  The thickness structure of the D substrate film obtained by the manufacturing method is appropriately determined in consideration of the effective expression of each of the above effects and the use. For example, the case of dicing, which is one of the effective uses, is illustrated. It is as follows.

First, in the case of layer A / layer B, the layer A (which is the central layer) is set to be thicker than at least the layer B. This is because, in particular, the depth of cut required by the dicer in dicing, and the required ρv10 ⁹ to 10 ¹² Ω · cm (even if the layer B is an electrical insulating layer) can be obtained more easily. In other words, it is better to make it thicker than layer B. In order to make this incision safely and reliably, it is necessary to cut through layer B to reach layer A. This is because it is not good to cut, so it is necessary to stop in this layer A.
This ρv is basically obtained by blending hydrophilic PE resin or hydrophilic PP resin as described above, but in the range where the thickness of the layer A is particularly thin, this ρv is smooth. It is also because it becomes difficult to influence expression.
Then, although it is the specific thickness of the layer A / layer B, the layer A is 50-200 micrometers, Preferably it is 60-150 micrometers. If it is less than 50 μm, the depth of cut is insufficient, and ρv is difficult to obtain. If it exceeds 200 μm, the thickness is more than necessary, and it is too hard to handle.
On the other hand, the layer B is 5 to 25 μm, preferably 10 to 20 μm. If the thickness is less than 5 μm, the above-described support function particularly in extensibility does not work, and if it exceeds 25 μm, the upper limit of ρv10 ¹² Ω · necessary even if the hydrophilic PE resin is blended within the above limit (20% by mass). It becomes difficult to obtain cm.

Moreover, in the case of layer B / layer A / layer B1, it can illustrate as follows.
The layers A and B may have the same thickness as described above, but the layer B1 with respect to the layer B may be thinner than the layer B from the viewpoint of providing lubricity, which is the original assisting action. However, it is better to set the same thickness for the D base film from the fear of warping.

Further, the D base film manufactured as described above is also provided with semiconductivity. In particular, its semiconductivity is ρv in electric resistance, which is mainly a blend amount of hydrophilic PE or hydrophilic PP resin in layer A, which is the central layer, and without melt-kneading more than necessary. Provided by the molding conditions. The range is about 10 ⁸ Ω · cm or more, and can be appropriately changed depending on the application.
In the present invention, for dicing which is an effective application, in addition to the expression of ρv, it is necessary to improve and balance other characteristics such as extensibility. From this characteristic improvement balance, it is a D substrate film of 10 ⁹ to 10 ¹² Ω · cm, more preferably 10 ¹⁰ to 10 ¹¹ Ω · cm. In other words, the lower limit of 10 ⁹ Ω · cm is better as the ρv is lower from the neutralization effect. However, if it is lower than this, there will be no further effect of improving other characteristics, and if it exceeds 10 ¹² Ω · cm, it will not be possible to effectively prevent the occurrence of static electricity at the time of wafer pick-up and other characteristics. The improvement effect is not seen.
In addition, this ρv is an electrical resistivity when a DC voltage is applied to both surfaces of layer A / layer B or layer B / layer A / layer B1 and measured, that is, a volume resistivity of the entire constituent layer. . Accordingly, the surface resistivity of the surface is essentially different. This is because even if the surface resistivity is in the range of 10 ⁹ to 10 ¹² Ω / □ or even less, it does not necessarily solve the problem of static electricity generation during pickup. In other words, for the fundamental solution to prevent static electricity, the static electricity generated on the surface must be immediately grounded and escape to the outside of the system. For this purpose, the entire D substrate film must be semiconductive, that is, ρv. I have to. In the case of a dicing mount having a predetermined resistivity only on the surface, static electricity does not easily flow out of the system even if it flows for a moment. As a result, it may be stored on the surface and cause dielectric breakdown, which does not solve the essential problem of static electricity generation.

As described above, each of the effects in the present invention is based on the central action of the layer A in the D-base film, but its expression is a hydrophilic PE resin or a hydrophilic property present in the polyethylene resin or the polypropylene resin. It relates to the dispersion state of PP resin. This can also be considered from the fact that production under melt kneading using, for example, a twin-screw extruder, which is described as the preferred production method, and that applies excessive shear stress, is not good.
In general, it is a common practice to form blends with sufficient melt-kneading so that these blended materials are as uniformly dispersed as possible, regardless of whether they are blends of resins or certain additives. It has become. However, in the present invention, it is an important means to avoid melt melting and kneading as much as possible as much as possible.

Compared with Example 1 described later (when the raw material is simply held in a dry blend) to confirm the dispersion state of the hydrophilic PE resin or hydrophilic PP resin present in the polyethylene resin or polypropylene resin. Using the two-layer film obtained in Example 7 (when sufficiently melted and biaxially kneaded is used as a raw material), the cross section is observed with a scanning electron microscope and an enlarged photograph (magnification 5000 times) is taken. It was. The results are shown in FIGS. Here, FIG. 1 is Example 1, and FIG. In each figure, the whitish part is the pellet PP 300 of the hydrophilic PP resin, and the blackish part is the crystalline PP resin of the matrix resin. It can be seen that there is a difference in the dispersion state. That is, in Example 1, the hydrophilic PP resin is dispersed in a large number of continuous layers, whereas in Comparative Example 7, most of the layers are isolated (although partly layered). Distributed. That is, in FIG. 1, the gap between the crystalline PP resin that is a matrix resin (electrically insulating) is very narrow, whereas in FIG. 2, the gap between the crystalline PP resin that is a matrix resin (electrically insulating) is very wide. .
This shows that the electric resistance of Example 1 is much smaller when comparing ρv, which is one of the effects. This is in a state where it is easier for electricity to pass, and this is considered to be caused by a large number of layer-dispersed hydrophilic PP resins.
By the way, both samples were allowed to stand in an atmosphere of 23 ° C. and 50% RH for 48 hours, and then the charge half-life (seconds) was measured using an Honest meter. The charge was halved in seconds. As a result, if static electricity is generated in the D base film when dicing, Example 1 is discharged at a rate four times faster than Comparative Example 7.

The D substrate film obtained by the manufacturing method is generally not used as it is. This is because it is necessary to provide an adhesive layer for adhesively fixing the dicing member on the layer B side. It is not preferable from the viewpoint of ρv expression that the thickness of the pressure-sensitive adhesive layer is increased more than necessary (although at least the thickness necessary for the pressure-sensitive adhesiveness is required). From this point, about 10 μm is exemplified.
For this adhesive layer, a general acrylic or rubber adhesive resin, an adhesive lowering resin by electron beam irradiation, or the like is used. The lamination of the adhesive layer with these resins is formed, for example, by separately coating the adhesive resin on a release paper with a gravure roll or the like, and transferring and laminating the adhesive resin on the layer B surface.

  The finally obtained D-base film with an adhesive layer is used as a dicing mount, but generally it is not used as it is. For example, in the case of wafer dicing, it is cut into a tape and rolled through a release paper. Used.

Hereinafter, examples will be described in detail together with comparative examples and reference examples.
The expandability and ρv in the text and in the following examples are values obtained by measurement as follows.
● Scalability,
The (D substrate) film obtained in each example is used as a sample, and 10 × 10 mm squares are drawn in advance on this film. Then, it is cut into a circle having a diameter of 300 mm, and this is brought into contact with the surface of a cylindrical body having an outer diameter of 150 mm (automatically moves up and down), and the entire periphery of the end of the film is chucked. Next, the cylinder is pushed up by 20 mm at a speed of 200 cm / min, and the film is expanded in all directions. Then, the vertical and horizontal expansion of the grid located at the center is measured. If the lengths in the vertical and horizontal directions are both 110% or more, the film is excellent as expandable film, and if at least one of the stretches is less than 110%, the film is inferior in expandability.
● ρv (Ω ・ cm)
The film obtained in each example was cut into A3 size, DC voltage 500V was applied to both sides of the film, and the resistance measuring instrument “HIRESTA IP / HR Blob” manufactured by Mitsubishi Chemical Corporation was applied to 10 locations. ρv is measured.
The measurement is performed after 10 seconds, and the value is shown as an average value.

(Example 1)
◎ Layer A resin,
As a bPP resin, a crystalline PP resin (manufactured by Grand Polymer Co., Ltd., a small amount of ethylene is randomly copolymerized in a variety F327) and a hydrophilic PP resin (manufactured by Sanyo Chemical Co., Ltd., a variety Pelestat 300, A blend resin obtained by dry blending 40% by mass with a tumble mixer having a melting point of 135 ° C. and a moisture content of 2400 ppm.
◎ Layer B resin,
Copolymerized ethylene resin with ethyl acrylate containing ethylene as a main component (trade name EVAFLEX manufactured by Mitsui Deupon Polychemical Co., Ltd., product EEA A-701, softening temperature 73 ° C.) and water content is 100 ppm.
Using the above resins as raw materials, this was co-extruded from a two-layer T-die having a slit width of 600 μm and adjusted to a temperature of 225 ° C. by two extruders and molding conditions having the following contents, and laminated simultaneously. Thus, a D-base film comprising layer A / layer B was obtained.

<Extruder and molding conditions for layer A>
◎ FF screw extruder: L / D = 28, measuring section groove depth 6.2mm, compression ratio 1.8
◎ Molding conditions: Extrusion temperature is 150 to 180 ° C. at a portion corresponding to the supply region, 190 to 215 ° C. at a portion corresponding to the compression region, and 205 to 205 ° at the portion corresponding to the metering region. Gradually increased temperature adjustment to 235 ° C., resin pressure 21.5 MPa, withdrawal rate 7.0%, cooling roll temperature 80 ° C.
<Extruder and molding conditions for layer B>
◎ FF screw extruder: L / D = 28, measuring section groove depth 1.5 mm, compression ratio 3.0,
◎ Molding conditions: Extrusion temperature is a barrel temperature of 150 to 175 ° C. in a portion corresponding to the supply region, a barrel temperature of 185 to 195 ° C. in a portion corresponding to the compression region, and a barrel temperature of 200 to 200 in a portion corresponding to the metering region. Gradually increased temperature adjustment to 205 ° C., resin pressure 18.6 MPa, withdrawal rate 7.0%, cooling roll temperature 80 ° C.

  The total thickness of the two-layer D substrate film obtained above was 80 μm, and each layer was layer A 65 μm and layer B 15 μm. Since the layer A was 4 times thicker, there was almost no warp, and it was in an integrally laminated state. Table 1 shows the extensibility and ρv measured using the film as a sample.

(Example 2)
◎ Layer A resin,
PP resin blend resin (Blend resin of amorphous polyolefin resin and crystalline PP resin, manufactured by Ube Industries, Ltd., variety CAP350, melting point 135 ° C.) 60% by mass as bPP resin, the same hydrophilicity as in Example 1 A blend resin obtained by dry blending 40% by mass of PP resin with a tumble mixer and having a moisture content of 1700 ppm.
◎ Layer B resin,
Copolymerized ethylene resin of ethylene and butyl acrylate (containing about 7% by mass) (trade name Rotoril variety 7BA01, melting point 107 ° C., manufactured by Atofina Japan Co., Ltd.), and has a moisture content of 200 ppm.
◎ resin for layer B1,
LDPE resin (manufactured by Ube Industries, cultivar F522N, melting point 109 ° C.) with a moisture content of 150 ppm.
Using each of the above resins as a raw material, this was co-extruded from a three-layer T-die having a slit width of 600 μm and adjusted to a temperature of 225 ° C. by three extruders and molding conditions having the following contents, and simultaneously laminated. Thus, a D substrate film comprising layer B / layer A / layer B1 was obtained.

<Extruder and molding conditions for layer A>
◎ FF screw extruder: L / D = 28, measuring section groove depth: 4.0 mm, compression ratio: 2.0,
Molding conditions: Same as Example 1, except that the resin pressure is 21.0 MPa.
<Extruder and molding conditions for layer B and layer B1>
Same as for layer B in Example 1, except that the resin pressure is 18.6 MPa.

  The total thickness of the three-layer D substrate film obtained above was 80 μm, and each layer was 60 μm of layer A and 10 μm of layer B and layer B1. There was no warpage, and it was in an integrally laminated state. Table 1 shows the extensibility and ρv measured using the film as a sample.

(Example 3)
◎ LDPE resin (produced by Ube Industries, variety F522N, melting point 109 ° C) as layer B resin bPE resin
A blend resin obtained by dry blending 50% by mass and 50% by mass of the same hydrophilic PP resin as in Example 1 with a tumble mixer and having a water content of 1000 ppm.
◎ Layer B resin,
The same EVAFLEX variety EEA A-701 as in Example 1.
Using the above resins as raw materials, this is co-extruded from a two-layer T-die with a slit width of 600 μm and controlled at a temperature of 200 ° C. by two extruders and molding conditions as described below, and laminated simultaneously. Thus, a D-base film comprising layer A / layer B was obtained.

<Extruder and molding conditions for layer A>
◎ The extrusion temperature is gradually increased to a barrel temperature of 145 to 170 ° C in the portion corresponding to the supply region, a barrel temperature of 175 to 185 ° C in the portion corresponding to the compression region, and a barrel temperature of 190 to 205 ° C in the portion corresponding to the metering region. The same as Example 1 except that the temperature is adjusted and the resin pressure is changed to 19.6 MPa.
<Extruder and molding conditions for layer B>
◎ Same as Example 1. However, the resin pressure is 17.6 MPa.

  The total thickness of the obtained two-layer D substrate film was 80 μm, and each layer was layer A 60 μm and layer B 20 μm. There was no warpage, and it was in an integrally laminated state. Table 1 shows the extensibility and ρv measured using the film as a sample.

Example 4
A blend resin obtained by dry blending the same blend PP resin “CAP350” 65 mass% as in Example 2 and 35 wt% hydrophilic PP resin “Pelestat 300” 35% by weight with a tumble mixer as the layer b resin bPP resin. The rate is 900 ppm.
◎ Layer B, Layer B1 resin (common),
The same LDPE resin “F522N” as in Example 2 and the same hydrophilic PP resin “Pelestat 300” 20 mass% are dry blended with a tumble mixer, and the moisture content is 1500 ppm.
Using each of the above resins as a raw material, this was co-extruded from a three-layer T-die having a slit width of 600 μm and adjusted to a temperature of 225 ° C. by three extruders and molding conditions having the following contents, and simultaneously laminated. Thus, a D substrate film comprising layer B / layer A / layer B1 was obtained.

<Extruder and molding conditions for layer A>
Same as Example 2. However, the resin pressure is 20.6 MPa.
<Extruder and molding conditions for layer B and layer B1>
◎ Same as Example 1. However, the resin pressure is 19.6 MPa.

  The total thickness of the obtained three-layer D substrate film was 80 μm, each layer was 40 μm in layer A, and layer B and layer B1 were 20 μm. There was no warpage, and it was in an integrally laminated state. Table 1 shows the extensibility and ρv measured using the film as a sample.

(Example 5)
A blend resin obtained by dry blending with a tumble mixer a blend PP resin “CAP350” 53% by mass same as Example 2 and 47% by mass of the same hydrophilic PP resin “Pelestat 300” 47% by mass as the resin BPP for layer A. The rate is 1500 ppm.
◎ Layer B, Layer B1 resin (common),
The same LDPE resin “F522N” as in Example 2 and a moisture content of 100 ppm.
Using each of the above resins as a raw material, this was co-extruded from a three-layer T-die having a slit width of 600 μm and adjusted to a temperature of 225 ° C. by three extruders and molding conditions having the following contents, and simultaneously laminated. Thus, a D substrate film comprising layer B / layer A / layer B1 was obtained.

<Extruder and molding conditions for layer A>
Same as Example 2.
<Extruder and molding conditions for layer B and layer B1>
◎ Same as Example 1.

  The total thickness of the obtained three-layer D substrate film was 80 μm, and each layer had a layer A of 60 μm, and layers B and B1 of 10 μm. There was no warpage, and it was in an integrally laminated state. Table 1 shows the extensibility and ρv measured using the film as a sample.

(Example 6)
◎ Layer A resin,
As the bPP resin, the same crystalline PP resin “variety F327” 50% by mass as in Example 1, polystyrene elastomer (hydrogenated styrene-butadiene copolymer elastomer) (manufactured by Nippon Styrene Rubber Co., Ltd., Dynalon 1320P) 15% by mass, and It is a blend resin obtained by dry blending three types of 35% by mass of the same hydrophilic PP resin “Pelestat 300” with a tumble mixer, and has a moisture content of 1200 ppm.
◎ Layer B resin,
The same LDPE resin “F522N” as in Example 2 and the same hydrophilic PP resin “Pelestat 300” 15% by mass are dry blended with a tumble mixer, and the moisture content is 500 ppm.
Using the above resins as raw materials, this was co-extruded from a two-layer T-die with a slit width of 600 μm and adjusted to a temperature of 215 ° C. by two extruders and molding conditions having the following contents, and laminated simultaneously. Thus, a D substrate film comprising two layers was obtained.

<Extruder and molding conditions for layer A>
◎ Same as Example 1. However, the resin pressure is 21.6 MPa.
<Extruder and molding conditions for layer B>
◎ Same as Example 1. However, the resin pressure is 19.6 MPa.

  The total thickness of the obtained D substrate film was 80 μm, and the thickness of each layer was 60 μm for layer A and 20 μm for layer B. There was almost no warp and it was in the state of integral lamination. Table 1 shows the extensibility and ρv measured using the film as a sample.

(Example 7)
◎ Layer A resin LDPE resin “F522N” 72% by mass and hydrophilic PP resin “Pelestat 300” 28% by mass are dry blended with a tumble mixer and have a moisture content of 950 ppm.
◎ Layer B resin,
Moisture content 140ppm with LDPE resin "F522N".
Using the above resins as raw materials, this was co-extruded from a two-layer T-die with a slit width of 600 μm, which was controlled at a temperature of 205 ° C., using the two extruders and molding conditions described below, and laminated simultaneously. Thus, a D substrate film comprising two layers of layer A / layer B was obtained.

<Extruder and molding conditions for layer A and layer B>
Both layers are the same, the extruder and molding conditions for layer B of Example 1.

  The total thickness of the two-layer D substrate film obtained above was 80 μm, and each layer was 60 μm in layer A and 20 μm in layer B. There was almost no warp and it was in the state of integral lamination. Table 1 shows the extensibility and ρv measured using the film as a sample.

(Comparative Example 1)
Using the same layer A resin as in Example 1, from a single layer T die having a slit width of 600 μm controlled at a temperature of 225 ° C., a single layer film consisting of only layer A was produced by the same layer A extruder and molding conditions. Obtained. However, the resin pressure is 21.6 MPa.
The thickness of the obtained film was 80 μm, and its extensibility and ρv were measured and summarized in Table 1.

(Comparative Example 2)
In Example 1, the other various conditions were the same except that the blend ratio of the crystalline PP resin “F327” of the layer A resin and the hydrophilic PP resin “Pelestat 300” was changed to 85 mass% and 15 mass%. Two-layer coextrusion was performed to obtain a two-layer film. The total thickness of the film was 80 μm, and each thickness was 60 μm for layer A and 20 μm for layer B. For this film, the extensibility and ρv were measured and summarized in Table 1.
The blend resin had a moisture content of 700 ppm.

(Comparative Example 3)
In Example 1, the other various conditions were the same except that the blend ratio of the crystalline PP resin “F327” for the layer A resin and the hydrophilic PP resin “Pelestat 300” was changed to 35 mass% and 65 mass%. Two-layer coextrusion was performed to obtain a two-layer film. The total thickness of the film varied from 70 to 85 μm (this is considered to be due to the poor moldability of the blend resin itself corresponding to layer A). The expandability and ρv of this film were also measured and summarized in Table 1.
In addition, the moisture content of this blend resin was 1500 ppm.

(Comparative Example 4)
In Example 1, except that the extruder used in the layer A is changed to an FF screw extruder having a groove depth of 2.0 mm and a compression ratio of 3.0, co-extrusion molding is carried out under the same conditions to form two layers. A laminated film consisting of The appearance was the same as in Example 1. The expandability and ρv of this film were measured and summarized in Table 1.

(Comparative Example 5)
In Example 1, the barrel temperature of the FF screw extruder for layer A is 150 to 165 ° C. corresponding to the supply region, 180 to 195 ° C. corresponding to the compression region, and 210 to 245 corresponding to the metering region. A laminated film consisting of two layers was obtained by performing coextrusion molding under the same conditions except that the temperature was set to ° C.
The expandability and ρv of this film were measured and summarized in Table 1.

(Comparative Example 6)
The blended resin obtained by the same dry blend as in Example 1 was divided into 2 parts, one was left in a humidity-controlled room of 65% RH, humidified to a moisture content of 3300 ppm, and the other was vacuum dried at 40 ° C. to a moisture content of 370 ppm. Each adjusted to.

Then, each of the two kinds of blend resins was used as a layer A equivalent resin, and two layers were coextruded under the same conditions as in Example 1 to obtain respective two layer films. Two-layer films made of a blend resin having a moisture content of 370 ppm and 3300 pp were called 37F and 330F, respectively, and the expandability and ρv were measured for each, and are summarized in Table 1.
37F showed no difference in appearance from the D substrate film of Example 1, but 330F showed a large number of irregularities (although very fine) on the surface of the layer corresponding to layer A.

(Comparative Example 7)
As a resin for layer A in Example 1, first, after dry blending with a tumble mixer, a biaxial melt kneading extruder (L / D = 7/1, the resin is carried inward by rotating in the opposite direction) (barrel heating temperature is The mixture was extruded as a gut while melt-kneaded at 150 to 205 ° C. (increase in high temperature), and chip-cut (about 1.5 mm diameter × 2 mm) with cooling. Except for using this kneaded blend resin as the resin for layer A, the film was molded and laminated under the same conditions as in Example 1 to obtain a two-layer film. The thickness of the obtained film was 80 μm, the layer A was 65 μm, the layer B was 15 μm, and the appearance was not different from the example. The extensibility and ρv of this were measured and summarized in Table 1.

A cross section of the two-layer film of Example 1 taken with a scanning electron microscope (5000 times magnification) A cross section of the two-layer film of Comparative Example 7 taken with a scanning electron microscope (x5000)

Explanation of symbols

In each photo, the whitish part corresponds to hydrophilic PP resin, and the black part corresponds to matrix bPP resin.

Claims (3)

A method for producing a substrate film for semiconductive dicing, wherein a semiconductive film A and a film B obtained by the following method are coextruded.
<Semiconductive film A>
Dry blend resin of 40 to 75% by mass of polypropylene resin or polyethylene resin and hydrophilic polyethylene resin or hydrophilic polypropylene resin in which polyoxyalkylene chain is block-bonded to 60 to 25% by mass of polyethylene chain or polypropylene chain The moisture content of the dry blend resin was adjusted to 500 to 3000 ppm, and this was adjusted to a metering section groove depth of 3.5 to 7.5 mm, a compression ratio of 1.5 to 2.5, and the blend resin temperature of 145. Supplied to a full-flight gradual decrease deep screw extruder that is gradually increased in temperature in the range of ˜235 ° C., extruded from a T-die controlled at a constant temperature within 210 to 230 ° C., and -40 to 100 ° C. Film A by the method of cooling and taking off
<Film B>
Full-flight gradual depth type in which a polyethylene resin is gradually increased and adjusted in the resin temperature range of 150 to 210 ° C. with a groove depth of 1.5 to 3.0 mm and a compression ratio of 2.5 to 3.5 mm. The film B obtained by feeding to a screw extruder, extruding in a film form from a T die controlled at a constant temperature of 210 to 230 ° C., cooling at 40 to 100 ° C., and taking it out. Semiconductive film A, film B, and film B1 obtained by the following method are coextruded and laminated in the order of film B / film A / film B1. Manufacturing method.
<Semiconductive film A>
Dry blend resin of 40 to 75 mass% polypropylene resin or polyethylene resin and hydrophilic polyethylene resin or hydrophilic polypropylene resin in which polyoxyalkylene chain is block-bonded to 60 to 25 mass% polyethylene chain or polypropylene chain The moisture content of the dry blend resin was adjusted to 500 to 3000 ppm, and this was adjusted to a metering section groove depth of 3.5 to 7.5 mm, a compression ratio of 1.5 to 2.5, and the blend resin temperature of 145. Supplied to a full-flight gradual decrease deep screw extruder that is gradually increased in temperature in the range of ˜235 ° C., extruded from a T-die controlled at a constant temperature within 210 to 230 ° C., and -40 to 100 ° C. Film A by the method of cooling and taking off
<Film B and Film B1>
Full-flight gradual depth type in which a polyethylene resin is gradually increased and adjusted in the resin temperature range of 150 to 210 ° C. with a groove depth of 1.5 to 3.0 mm and a compression ratio of 2.5 to 3.5 mm. The film B and the film obtained by feeding to a screw extruder, extruding in a film form from a T die controlled at a constant temperature of 210 to 230 ° C., cooling at 40 to 100 ° C. without drawing, and taking the film. B1. The substrate film for semiconductive dicing according to claim 1, which has a volume resistivity of 10 ⁹ to 10 ¹² Ω · cm under application of a DC voltage of 500 V.