Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
  • C09J11/02—Non-macromolecular additives
  • C09J11/04—Non-macromolecular additives inorganic
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J129/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an alcohol, ether, aldehydo, ketonic, acetal, or ketal radical; Adhesives based on hydrolysed polymers of esters of unsaturated alcohols with saturated carboxylic acids; Adhesives based on derivatives of such polymers
  • C09J129/02—Homopolymers or copolymers of unsaturated alcohols
  • C09J129/04—Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J7/00—Adhesives in the form of films or foils
  • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
  • C09J7/38—Pressure-sensitive adhesives [PSA]
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P52/00—Grinding, lapping or polishing of wafers, substrates or parts of devices
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P95/00—Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass

Definitions

• the present invention relates to temporary protective materials.
• Patent Document 1 discloses a configuration in which a protective layer is formed by covering the wafer surface with a liquid mixture of polyvinyl alcohol, sodium lauryl ether sulfate, and sodium ⁇ -olefin sulfonate. is disclosed.
• Patent Document 2 discloses a wafer dividing method in which a film containing a polyvinyl alcohol-based polymer having a degree of polymerization of 100 to 3000 and a degree of saponification of 70 to 99 mol % is attached to a semiconductor wafer.
• peripheral elements such as capacitors and solder balls are mounted everywhere on the top surface, back surface, etc. of the chip-type electronic component in addition to the integrated circuit.
• peripheral elements may be arranged on the rear surface side before the integrated circuit is mounted on the upper surface due to process convenience and the like. In such a case, when an integrated circuit is mounted on the top surface, the element on the back side may come into contact with the stage, and the chip-type electronic component may be damaged or damaged.
• protective sheets are used to protect the elements that are mounted on the rear surface first, but such protective sheets need to be removed after multiple layers of integrated circuits are arranged on the front surface side.
• the protective sheet which is placed on the back side for the purpose of protecting the elements that will be mounted first, is used to protect the substrate from contamination caused by processing such as cutting, cutting, drilling, etc. and other processes when placing multiple layers of integrated circuits on the top surface.
• a polyvinyl alcohol-based resin is used, there is a problem that it cannot withstand water washing and dissolves.
• An object of the present invention is to provide a temporary protective material that has both water resistance to protect the component mounting surface in the process of mounting a semiconductor substrate and deformability that can follow the components on the semiconductor substrate, and is excellent in hot water removability. do.
• the present disclosure (1) includes at least an A layer and a B layer, wherein the A layer contains a polyvinyl alcohol resin (A) having a saponification degree of 95 mol% or more and 100 mol% or less and boric acid,
• the B layer contains a polyvinyl alcohol resin (B) having a saponification degree of 70 mol% or more and less than 95 mol% and boric acid, and the saponification degree of the polyvinyl alcohol resin (A) and the polyvinyl alcohol
• the temporary protective material has a saponification degree different from that of the system resin (B) by 5 mol% or more.
• the present disclosure (2) is the temporary protective material of the present disclosure (1), which has a total of three layers or more of the A layer and the B layer, and the A layer and the B layer are laminated to each other.
• the present disclosure (3) is the temporary protective material according to the present disclosure (1) or (2), wherein the total thickness is 100 ⁇ m or more, and the thickness of the layer B is 50% or more and 90% or less of the total thickness.
• the present disclosure (4) is any of the present disclosure (1) to (3), wherein the content of boric acid in the A layer and the content of boric acid in the B layer satisfy the following formulas (1) and (2) Temporary protection for any combination of heels.
• Sd is the degree of saponification (mol%) of the polyvinyl alcohol resin constituting each layer
• Mw is the weight average molecular weight of the polyvinyl alcohol resin constituting each layer
• C is boric acid in each layer.
• the content (% by weight) of Gu is 70 and Gd is 5.
• the present inventors have found that by forming a laminate containing a polyvinyl alcohol-based resin having a saponification degree within a predetermined range and layers A and B containing boric acid, the component mounting surface in the mounting process of the semiconductor substrate It was found that a temporary protective material having sufficient water resistance to protect and deformability that can follow the parts on the semiconductor substrate, and excellent hot water removability can be achieved, and the present invention was completed.
• the temporary protective material of the present invention includes an A layer containing a polyvinyl alcohol resin (A) having a saponification degree of 95 mol% or more and 100 mol% or less and boric acid, and a saponification degree of 70 mol% or more and 95 It has a B layer containing less than mol % of polyvinyl alcohol resin (B) and boric acid. Moreover, the difference between the saponification degree of the polyvinyl alcohol resin (A) and the saponification degree of the polyvinyl alcohol resin (B) is 5 mol % or more. With the above configuration, it is possible to achieve both water resistance and deformability.
• the layer A contains a polyvinyl alcohol-based resin (A) having a degree of saponification of 95 mol % or more and 100 mol % or less.
• a temporary protective material that can be easily removed with warm water can be obtained.
• the degree of saponification of the polyvinyl alcohol resin (A) is 95 mol % or more and 100 mol % or less. By setting it as the said range, water resistance can fully be improved.
• the degree of saponification is more preferably 96.5 mol% or more, still more preferably 98 mol% or more, preferably 99.7 mol% or less, and preferably 99 mol% or less. More preferred.
• the degree of saponification can be measured, for example, by a method conforming to JIS K6726.
• the degree of saponification indicates the ratio of units actually converted to vinyl alcohol units among the vinyl ester units that can be converted to vinyl alcohol units by saponification.
• the degree of saponification can be controlled, for example, by adjusting saponification conditions, that is, hydrolysis conditions.
• the weight average molecular weight (Mw) of the polyvinyl alcohol resin (A) is preferably 8,000 or more, and preferably 150,000 or less. By setting it as the above range, it is possible to achieve both high water resistance and solubility in hot water.
• the weight-average molecular weight is more preferably 9,000 or more, further preferably 10,000 or more, more preferably 100,000 or less, even more preferably 50,000 or less, and particularly preferably 40,000 or less. .
• the number average molecular weight (Mn) of the polyvinyl alcohol resin (A) is preferably 4000 or more, more preferably 4500 or more, still more preferably 5000 or more, and preferably 90000 or less. , 60000 or less, and even more preferably 30000 or less.
• the ratio (Mw/Mn) between the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polyvinyl alcohol resin (A) is preferably 1.2 or more, and preferably 1.4 or more. It is more preferably 1.6 or more, preferably 5.0 or less, more preferably 3.5 or less, and even more preferably 2.0 or less.
• the weight average molecular weight (Mw) and number average molecular weight (Mn) are, for example, measured by a gel permeation chromatography (GPC) method, a polyvinyl ester before saponification is measured by a GPC method, and a polyvinyl alcohol resin.
• the polyvinyl ester obtained by re-esterification by the GPC method can be obtained by measuring the polyvinyl ester obtained by re-esterification by the GPC method, measuring the viscosity of the aqueous solution according to JIS K6726, or the like.
• columns such as TSKgel (manufactured by Tosoh Corp.), PLgel (manufactured by AMR Corp.), KF-806, KF-807 (manufactured by Shodex Corp.) and the like can be used using polystyrene as a standard.
• the average degree of polymerization of the polyvinyl alcohol resin (A) is preferably 180 or more, more preferably 200 or more, still more preferably 220 or more, preferably 3400 or less, and 2300 or less. is more preferably 1200 or less, and particularly preferably 700 or less.
• the average degree of polymerization can be determined, for example, by measuring polyvinyl acetate before saponification by gel permeation chromatography (GPC) or by measuring the viscosity of an aqueous solution according to JIS K6726.
• the polyvinyl alcohol-based resin (A) may be a mixed resin of a plurality of polyvinyl alcohol-based resins having different compositions as long as the saponification degree satisfies the above range.
• the degree of saponification is the content (weight) of each polyvinyl alcohol resin in the polyvinyl alcohol resin (A). %) and the degree of saponification (mol%) are multiplied and divided by 100, and then summed.
• the content (% by weight) of each polyvinyl alcohol resin in the polyvinyl alcohol resin (A) is multiplied by each value. It can be obtained by summing the values divided by 100.
• the polyvinyl alcohol-based resin (A) may be a modified polyvinyl alcohol-based resin having structural units other than vinyl ester units and vinyl alcohol units.
• modified polyvinyl alcohol resin include those modified with a modifying group such as a hydrophilic group such as a sulfonic acid group, a pyrrolidone ring group, an amino group, and a carboxyl group.
• a modifying group such as a hydrophilic group such as a sulfonic acid group, a pyrrolidone ring group, an amino group, and a carboxyl group.
• these hydrophilic groups also include salts such as sodium salts and potassium salts thereof.
• the content of the structural unit having a modifying group in the polyvinyl alcohol resin (A) is preferably 1 mol% or more, more preferably 3 mol% or more, and particularly preferably 5 mol% or more. It is preferably 20 mol % or less, more preferably 15 mol % or less, and particularly preferably 12 mol % or less.
• the content of the structural unit possessed by the modifying group is the content (% by weight) of each polyvinyl alcohol-based resin in the polyvinyl alcohol-based resin (A) and the modified It can be obtained by multiplying the content (mol %) of the structural unit having a group and dividing by 100 and totaling the results.
• the content of the polyvinyl alcohol resin (A) in the layer A is preferably 50% by weight or more, more preferably 70% by weight or more, and even more preferably 85% by weight or more.
• the upper limit of the content of the polyvinyl alcohol resin is not particularly limited, but depending on the purpose, storage stabilizers, mechanical property modifiers, thickeners, preservatives, antifungal agents, dispersion stabilizers, spacers ( It is explicitly determined by including other components such as gap adjusters), other polymers, and the like.
• the upper limit is usually less than 100% by weight, preferably 99.975% by weight or less, more preferably 99.9% by weight or less.
• the polyvinyl alcohol-based resin (A) can be obtained by polymerizing a vinyl ester to obtain a polymer and then saponifying, ie, hydrolyzing the polymer according to a conventionally known method. Alkali or acids are generally used as saponification catalysts.
• vinyl ester examples include vinyl acetate, vinyl formate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl versatate, vinyl laurate, vinyl stearate and vinyl benzoate.
• the method of polymerizing the vinyl ester is not particularly limited, and examples thereof include solution polymerization, bulk polymerization and suspension polymerization.
• polymerization catalyst used for polymerizing the vinyl ester examples include 2-ethylhexylperoxydicarbonate ("TrigonoxEHP" manufactured by Tianjin McEIT), 2,2'-azobisisobutyronitrile (AIBN), t-butyl peroxyneodecanoate, bis(4-t-butylcyclohexyl)peroxydicarbonate, di-n-propylperoxydicarbonate, di-n-butylperoxydicarbonate, di-cetylperoxydicarbonate and di-s-butylperoxy A dicarbonate etc. are mentioned. Only one kind of the polymerization catalyst may be used, or two or more kinds thereof may be used in combination.
• the polyvinyl alcohol-based resin may be a saponified polymer of vinyl ester and other unsaturated monomers.
• Other unsaturated monomers include monomers other than the above vinyl esters and having unsaturated double bonds such as vinyl groups.
• Olefins include ethylene, propylene, 1-butene and isobutene.
• (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, and n-butyl (meth)acrylate. , and 2-ethylhexyl (meth)acrylate.
• Unsaturated acids other than (meth)acrylic acid, salts and esters thereof include maleic acid and its salts, maleic acid esters, itaconic acid and its salts, itaconic acid esters, methylenemalonic acid and its salts, methylenemalonic acid esters, etc.
• (Meth)acrylamides include acrylamide, n-methylacrylamide, N-ethylacrylamide, N,N-dimethylacrylamide and the like.
• N-vinylamides include N-vinylpyrrolidone and the like.
• Vinyl ethers include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl ether and n-butyl vinyl ether.
• Nitriles include (meth)acrylonitrile and the like.
• Vinyl halides include vinyl chloride and vinylidene chloride. Allyl compounds include allyl acetate and allyl chloride. Examples of vinylsilyl compounds include vinyltrimethoxysilane.
• Examples of the sulfonic acid group-containing compound include (meth)acrylamidoalkanesulfonic acid such as (meth)acrylamidopropanesulfonic acid and salts thereof, olefinsulfonic acids such as ethylenesulfonic acid, allylsulfonic acid and methallylsulfonic acid, and salts thereof. mentioned.
• Examples of amino group-containing compounds include allylamine, polyoxyethylene allylamine, polyoxypropylene allylamine, polyoxyethylene vinylamine, polyoxypropylene vinylamine, and the like.
• the layer A contains boric acid.
• boric acid By containing the boric acid, a crosslinked structure or the like is formed in the polyvinyl alcohol-based resin (A) by heating, and a temporary protective material having sufficient water resistance and heat resistance can be obtained.
• boric acid examples include orthoboric acid, metaboric acid, and tetraboric acid. Further, boric acid also includes salts of boric acid.
• the boric acid salts include borax, alkali metal salts such as sodium salts and potassium salts, alkaline earth metal salts such as calcium salts and magnesium salts, aluminum salts, triethylamine, triethanolamine, morpholine, piperazine, pyrrolidine, and the like. and organic amine salts of. These boric acids may be used individually by 1 type, and may be used in combination of 2 or more type.
• the boric acid content in the layer A is preferably 0.025% by weight or more, and preferably 15% by weight or less. By setting it as the said range, sufficient water resistance and heat resistance can be provided by heating.
• the boric acid content is more preferably 0.25% by weight or more, still more preferably 0.4% by weight or more, more preferably 10% by weight or less, and 5% by weight or less. It is even more preferable to have
• the content of the boric acid in the layer A is preferably 0.025 parts by weight or more, more preferably 0.25 parts by weight or more, relative to 100 parts by weight of the polyvinyl alcohol resin (A). It is preferably 0.4 parts by weight or more, more preferably 17.6 parts by weight or less, more preferably 11.1 parts by weight or less, and preferably 5.3 parts by weight or less. More preferred.
• the boric acid content in the layer A preferably satisfies the following formulas (1) and (2).
• Sd is the degree of saponification (mol%) of the polyvinyl alcohol resin constituting each layer
• Mw is the weight average molecular weight of the polyvinyl alcohol resin constituting each layer
• C is boric acid in each layer.
• the content (% by weight) of Gu is 70 and Gd is 5.
• Gu is the desired water resistance with respect to the gel fraction of the temporary protective material when the temporary protective material after being heated at 180 ° C. for 30 minutes is immersed in water at 35 ° C. It means a gel fraction value sufficient to be able to exhibit, preferably 80, more preferably 90.
• Gd is the gel fraction of the temporary protective material when the temporary protective material after heating at 180°C for 30 minutes is immersed in water at 80°C. value, preferably 3.5, more preferably 2.
• the temporary protective material has water resistance capable of protecting the component mounting surface in the semiconductor substrate mounting process and can be easily removed with warm water.
• the boric acid content in the layer A satisfies the following formulas (3) and (4).
• Sd is the degree of saponification (mol%) of the polyvinyl alcohol resin in each layer
• Mw is the weight average molecular weight of the polyvinyl alcohol resin in each layer
• C is the boric acid content in each layer. (% by weight).
• the A layer contains other ingredients such as storage stabilizers, mechanical property modifiers, thickeners, preservatives, antifungal agents, dispersion stabilizers, spacers (gap adjusters), etc., if necessary. However, it is preferably composed of polyvinyl alcohol-based resin (A) and boric acid.
• the layer B contains a polyvinyl alcohol-based resin (B) having a degree of saponification of 70 mol % or more and less than 95 mol %.
• a temporary protective material that can be easily removed with warm water can be obtained.
• the degree of saponification of the polyvinyl alcohol-based resin (B) is 70 mol % or more and less than 95 mol %. By setting it as the said range, lamination suitability and water resistance can fully be improved.
• the degree of saponification is more preferably 80 mol % or more, still more preferably 85 mol % or more, preferably 93 mol % or less, and even more preferably 90 mol % or less.
• the difference between the saponification degree of the polyvinyl alcohol resin (A) and the saponification degree of the polyvinyl alcohol resin (B) is 5 mol % or more. By satisfying the above relationship, both water resistance and deformability during lamination can be achieved.
• the difference in saponification degree is preferably 6.5 mol% or more, more preferably 8 mol% or more, preferably 20 mol% or less, and more preferably 15 mol% or less. .
• the weight average molecular weight (Mw) of the polyvinyl alcohol resin (B) is preferably 8,000 or more, and preferably 150,000 or less. By setting it as the above range, it is possible to achieve both high water resistance and solubility in hot water.
• the weight average molecular weight is more preferably 10,000 or more, still more preferably 14,000 or more, more preferably 100,000 or less, and even more preferably 50,000 or less.
• the number average molecular weight (Mn) of the polyvinyl alcohol resin (B) is preferably 4000 or more, more preferably 4500 or more, still more preferably 5000 or more, and preferably 90000 or less. , 60000 or less, and even more preferably 30000 or less.
• the ratio (Mw/Mn) between the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polyvinyl alcohol-based resin (B) is preferably 1.2 or more, more preferably 1.4 or more. It is more preferably 1.6 or more, preferably 5.0 or less, more preferably 3.5 or less, and even more preferably 2.0 or less.
• the average degree of polymerization of the polyvinyl alcohol resin (B) is preferably 180 or more, more preferably 220 or more, still more preferably 310 or more, preferably 3400 or less, and 2300 or less. is more preferable, and 1200 or less is even more preferable.
• the polyvinyl alcohol-based resin (B) may be a modified polyvinyl alcohol-based resin having structural units other than vinyl ester units and vinyl alcohol units.
• Examples of the modified polyvinyl alcohol-based resin include those similar to the polyvinyl alcohol-based resin (A).
• the content of the structural unit having a modifying group in the polyvinyl alcohol resin (B) is preferably 1 mol% or more, more preferably 3 mol% or more, and particularly preferably 5 mol% or more. It is preferably 20 mol % or less, more preferably 15 mol % or less, and particularly preferably 12 mol % or less.
• the polyvinyl alcohol-based resin (B) may be a mixed resin of a plurality of polyvinyl alcohol-based resins having different compositions, as long as the saponification degree satisfies the above range.
• the saponification degree, weight average molecular weight, number average molecular weight, average degree of polymerization, content of structural units having modifying groups The amount can be determined in the same manner as for the polyvinyl alcohol resin (A).
• the content of the polyvinyl alcohol-based resin (B) in the layer B is preferably 50% by weight or more, more preferably 70% by weight or more, and even more preferably 85% by weight or more.
• the upper limit of the content of the polyvinyl alcohol resin is not particularly limited, but depending on the purpose, storage stabilizers, mechanical property modifiers, thickeners, preservatives, antifungal agents, dispersion stabilizers, spacers ( It is explicitly determined by including other components such as gap adjusters), other polymers, and the like.
• the upper limit is usually less than 100% by weight, preferably 99.975% by weight or less, more preferably 99.9% by weight or less.
• the content of the polyvinyl alcohol resin (B) in the layer) is preferably 0.1 or more, more preferably 0.2 or more, still more preferably 0.3 or more, and 2 or less. It is preferably 1.5 or less, more preferably 1.0 or less.
• Examples of the method for producing the polyvinyl alcohol-based resin (B) include a method of adjusting the saponification conditions in the same method as for the polyvinyl alcohol-based resin (A).
• the B layer contains boric acid.
• boric acid By containing the boric acid, a crosslinked structure or the like is formed in the polyvinyl alcohol-based resin (B) by heating, and a temporary protective material having sufficient water resistance and heat resistance can be obtained.
• boric acid examples include the same ones as in the layer A described above.
• the boric acid content in the layer B is preferably 0.025% by weight or more, and preferably 15% by weight or less. By setting it as the said range, sufficient water resistance and heat resistance can be provided by heating.
• the boric acid content is more preferably 0.25% by weight or more, still more preferably 0.4% by weight or more, more preferably 10% by weight or less, and 5% by weight or less. It is even more preferable to have
• the boric acid content in the B layer is preferably 0.025 parts by weight or more, more preferably 0.25 parts by weight or more, relative to 100 parts by weight of the polyvinyl alcohol resin (B). It is preferably 0.4 parts by weight or more, more preferably 17.6 parts by weight or less, more preferably 11.1 parts by weight or less, and preferably 5.3 parts by weight or less. More preferred.
• the boric acid content in the layer B preferably satisfies the following formulas (1) and (2).
• Sd is the degree of saponification (mol%) of the polyvinyl alcohol resin constituting each layer
• Mw is the weight average molecular weight of the polyvinyl alcohol resin constituting each layer
• C is boric acid in each layer.
• the content (% by weight) of Gu is 70 and Gd is 5.
• Gu is the desired water resistance with respect to the gel fraction of the temporary protective material when the temporary protective material after being heated at 180 ° C. for 30 minutes is immersed in water at 35 ° C. It means a gel fraction value sufficient to be able to exhibit, preferably 80, more preferably 90.
• Gd is the gel fraction of the temporary protective material when the temporary protective material after heating at 180°C for 30 minutes is immersed in water at 80°C. value, preferably 3.5, more preferably 2.
• the temporary protective material has water resistance capable of protecting the component mounting surface in the semiconductor substrate mounting process and can be easily removed with warm water.
• the boric acid content in the layer B satisfies the following formulas (3) and (4).
• Sd is the degree of saponification (mol%) of the polyvinyl alcohol resin in each layer
• Mw is the weight average molecular weight of the polyvinyl alcohol resin in each layer
• C is the boric acid content in each layer. (% by weight).
• the B layer contains other components such as a storage stabilizer, a mechanical property modifier, a thickener, a preservative, an anti-mold agent, a dispersion stabilizer, and a spacer (gap adjuster), if necessary.
• a storage stabilizer such as a hard disk, a hard disk, a hard disk, a hard disk, a hard disk, a hard disk, a hard disk, a hard disk, a styl alcohol-based resin (B) and boric acid.
• the temporary protective material of the present invention should have at least the A layer and the B layer, and may further have a layer having another configuration such as a layer made of a polyvinyl alcohol-based resin, but the A layer and a B layer.
• the temporary protective material of the present invention can exhibit sufficient functions as long as it has at least two layers of A layer and B layer, but if necessary, it may have a total of three layers or more of A layer and B layer. You can add more layers.
• the temporary protective material of the present invention may have at least the A layer and the B layer, and may have another layer between the A layer and the B layer. Preferably, they are laminated on each other.
• that the A layer and the B layer are laminated to each other means that the A layer and the B layer are directly laminated without interposing another layer.
• the temporary protective material of the present invention has a two-layer structure of A layer / B layer, a three-layer structure such as A layer / B layer / A layer, B layer / A layer / B layer, A layer / B layer / A It may be a structure of four or more layers such as layer/B layer.
• the temporary protective material of the present invention has a structure of three or more layers, the A layers and the B layers may have the same composition or different compositions.
• the surface to be bonded to the semiconductor substrate may be the A layer or the B layer.
• the thickness of the temporary protective material changes depending on the unevenness of the part when it is immersed in water or when it swells due to water absorption, so there is a difference in dimensional change and cracks. etc. are more likely to occur.
• the amount of swelling increases, and it becomes easy to peel off from the electronic substrate (semiconductor substrate) that is being protected.
• by appropriately laminating the A layer and the B layer it is possible to achieve both water resistance that can protect the component mounting surface and deformability that can follow the components on the semiconductor substrate. Cracks are less likely to occur when immersed in water, and dimensional changes as a whole can also be suppressed. This makes it difficult to separate from the electronic substrate (semiconductor substrate), and further improves the water resistance.
• the shape of the temporary protective material of the present invention is not particularly limited, and examples thereof include film-like, sheet-like, plate-like, powdery, granular, flake-like, and pellet-like shapes.
• the total thickness of the temporary protective material of the present invention is not particularly limited, it is preferably 100 ⁇ m or more. By setting it as the said range, the function which protects a component mounting surface can fully be achieved.
• the total thickness is more preferably 150 ⁇ m or more, still more preferably 200 ⁇ m or more, particularly preferably 300 ⁇ m or more, preferably 1000 ⁇ m or less, more preferably 700 ⁇ m or less, and 500 ⁇ m. More preferably:
• the thickness and shape of the temporary protective material of the present invention are appropriately determined in consideration of the shape of the material to be protected, the size of unevenness, and the like.
• the thickness of the layer B is preferably 50% or more and preferably 90% or less of the total thickness.
• the thickness of the B layer with respect to the total thickness is more preferably 60% or more, still more preferably 70% or more, more preferably 86% or less, and even more preferably 80% or less.
• the thickness of the B layers means the total thickness of the plurality of B layers.
• the ratio of the thickness of the layer A to the thickness of the layer B is preferably 0.11 or more, and is 0.17 or more. is more preferably 0.25 or more, particularly preferably 1 or less, more preferably 0.67 or less, and particularly preferably 0.4 or less.
• the temporary protective material of the present invention preferably has a gel fraction of 70% by weight or more when subjected to ultrasonic vibration for 15 minutes in water at 35° C. after heating.
• the gel fraction is 70% by weight or more, the function of protecting the component mounting surface can be sufficiently achieved in the mounting process of the semiconductor substrate.
• the gel fraction is more preferably 80% by weight or more, still more preferably 90% by weight or more, and usually 100% by weight or less.
• heating conditions for example, heating at 180° C. for 30 minutes is preferable. Specifically, a method of leaving the temporary protective material in a hot air circulation oven at a temperature of 180° C. for 30 minutes can be used.
• the above gel fraction can be obtained, for example, by heating the temporary protective material of the present invention formed into a film shape at 180° C. for 30 minutes, immersing it in water at 35° C., stirring it with an ultrasonic cleaner, and dissolving it. Next, the weight of the undissolved component is measured, and the ratio of the weight of the undissolved component to the weight of the temporary protective material before immersion can be calculated.
• the frequency of the ultrasonic waves to be applied is appropriately selected in consideration of detergency, damage to the object to be cleaned, and the like. An example is 45 kHz. At a lower frequency, although the detergency improves, the load on the object to be washed increases.
• the temporary protective material of the present invention preferably has a gel fraction of 5% by weight or less when immersed in water at 80° C. for 15 minutes after heating.
• the gel fraction is preferably 5% by weight or less, more preferably 3.5% by weight or less, particularly preferably 2% by weight or less, and usually 0% by weight or more.
• the heating condition for example, heating at 180° C. for 30 minutes is preferable. Specifically, a method of leaving the temporary protective material in a hot air circulation oven at a temperature of 180° C. for 30 minutes can be used.
• the gel fraction can be obtained, for example, by heating the temporary protective material of the present invention formed into a film at 180° C. for 30 minutes and then dissolving it by immersing it in water at 80° C. for 15 minutes. It can be obtained by measuring and calculating the ratio of the weight of the undissolved component to the weight of the temporary protective material before immersion.
• the temporary protective material of the present invention preferably has a 90° direction peel force of 100 N/m or more, more preferably 200 N/m or more after being attached to a SUS plate and heated at 100° C. for 30 minutes. More preferably, it is 350 N/m or more.
• the 90° direction peel force can be measured, for example, by the following method. First, after moistening the surface of a temporary protective material with a width of 25 mm with water, it was attached to a SUS plate at a speed of 10 mm/sec using a 2-kg compression rubber roller under an environment of room temperature of 23°C and relative humidity of 50%. . Then, heat treatment is performed once at 100° C. for 30 minutes. Here, the heat treatment at 100° C.
• the temporary protective material is peeled off at a speed of 5 mm/min according to JIS Z0237, and the 90° direction peel force is measured.
• the method for producing the temporary protective material of the present invention is not particularly limited, and examples thereof include the following methods. First, an aqueous polyvinyl alcohol-based resin (A) solution and an aqueous boric acid solution are prepared and mixed to prepare an aqueous solution for the A layer. Next, the layer A solution is coated on the substrate and dried to form the layer A. Further, an aqueous polyvinyl alcohol-based resin (B) solution and an aqueous boric acid solution are prepared and mixed to prepare an aqueous solution for layer B. Next, the B layer aqueous solution is applied onto the substrate and dried to form the B layer. The layers A and B thus obtained are separated from the substrate and laminated using a laminator to produce a temporary protective material having layers A and B.
• a plurality of A layers and B layers may be produced and laminated alternately to produce a temporary protective material.
• the aqueous solution for the layer B is applied onto the layer A and dried to form the layer B, thereby forming the temporary protective material.
• the material constituting the base material is not particularly limited, it is preferably a material having heat resistance.
• heat-resistant materials include polyethylene terephthalate, polyethylene naphthalate, polyacetal, polyamide, polycarbonate, polyphenylene ether, polybutylene terephthalate, ultra-high molecular weight polyethylene, syndiotactic polystyrene, polyarylate, polysulfone, polyethersulfone, Examples include polyphenylene sulfide, polyetheretherketone, polyimide, polyetherimide, fluororesin, and liquid crystal polymer. Since it is necessary to peel off the temporary protective material of the present invention after drying, it is preferable to subject the surface of the substrate to a weak release treatment as necessary.
• Examples of the coating method include cast method, roll coating method, lip coating method, spin coating method, screen coating method, fountain coating method, dipping method, and spray method.
• drying method examples include a method of natural drying and a method of drying by heating at a temperature at which air bubbles are not generated due to foaming of the solvent.
• the thickness of the base material is not particularly limited, but a preferable lower limit is 20 ⁇ m, and a more preferable lower limit is 25 ⁇ m. If the base material is thin, the base material will be deformed during heat drying, making it difficult to obtain a temporary protective material with a constant thickness.
• the use of the temporary protective material of the present invention is not particularly limited, but it is preferably used in the manufacturing process of electronic components such as semiconductor devices and display devices.
• the temporary protective material of the present invention is resistant to peeling even at high temperatures in the process of mounting semiconductor substrates, has excellent water resistance, and is resistant to peeling even after washing. In addition, it is excellent in deformability, and in the mounting process of the semiconductor substrate, it can follow the component mounting surface and exhibit a sufficient protective function. Furthermore, after the mounting process is completed, the residue can be easily removed with warm water, preventing contamination of the electronic components.
• the temporary protective material of the present invention can protect the component mounting surface by attaching it to the component mounting surface in the mounting process of the semiconductor substrate.
• the temporary protective material of the present invention can promote cross-linking and improve water resistance by heat treatment after being attached to a component mounting surface in the process of mounting a semiconductor substrate.
• the heating conditions are usually 180° C. for 30 minutes, but are not particularly limited.
• the heat treatment temperature is preferably 130° C. or higher, more preferably 150° C. or higher, still more preferably 160° C. or higher, preferably 190° C. or lower, more preferably 185° C. or lower, and still more preferably 180° C. or lower.
• the heat treatment time is preferably 5 minutes or longer, more preferably 15 minutes or longer, preferably 60 minutes or shorter, more preferably 45 minutes or shorter, and even more preferably 30 minutes or shorter. However, when the treatment temperature is low, it is preferable to lengthen the heat treatment time, and when the treatment temperature is high, it is preferable to shorten the heat treatment time.
• the heat treatment time and the heat treatment time can be appropriately selected in consideration of the shape, heat capacity, heat resistance, etc. of the object to be protected, and the required water resistance, heat resistance, easy solubility, and the like.
• ADVANTAGE OF THE INVENTION it is possible to provide a temporary protective material that has both water resistance that can protect the component mounting surface in the mounting process of a semiconductor substrate and deformability that can follow the components on the semiconductor substrate, and that is excellent in hot water removability. can.
• the polymerization rate was measured by 1 H-NMR measurement and found to be 99%.
• the remaining vinyl acetate monomer was removed together with methanol under reduced pressure while adding methanol to obtain a methanol solution containing 50% by weight of polyvinyl acetate.
• a methanol solution of sodium hydroxide was added so that the amount of sodium hydroxide was 0.07 mol % with respect to vinyl acetate, and saponification was carried out at 40°C.
• the obtained solid content was pulverized, washed with methanol, and dried to obtain PVA1.
• the degree of saponification of the obtained PVA1 was measured by a method according to JIS K6726.
• the weight-average molecular weight of the polyvinyl alcohol-based resin was obtained by measuring the weight-average molecular weight in terms of polystyrene by gel permeation chromatography using LF-804 (manufactured by SHOKO) as a column. As a result, the degree of saponification and weight average molecular weight were 98.4 mol % and 15000, respectively.
• Example 1 Preparation of aqueous solution for layer A
• the solution was cooled to room temperature to obtain a 20% by weight polyvinyl alcohol-based resin aqueous solution.
• PVA1 was used as the polyvinyl alcohol resin.
• boric acid (B(OH) 3 ) was dissolved in water to obtain an aqueous boric acid solution with a concentration of 3% by weight.
• aqueous polyvinyl alcohol-based resin solution and an aqueous boric acid solution were mixed so that 0.412 parts by weight of boric acid was added to 100 parts by weight of polyvinyl alcohol-based resin, and defoamed to obtain an aqueous solution for layer A.
• aqueous solution for layer B After dissolving the polyvinyl alcohol-based resin in warm water of 90° C. or higher, the solution was cooled to room temperature to obtain an aqueous polyvinyl alcohol-based resin solution having a concentration of 20% by weight. PVA2 was used as the polyvinyl alcohol resin. Also, boric acid (B(OH) 3 ) was dissolved in water to obtain an aqueous boric acid solution with a concentration of 3% by weight.
• aqueous polyvinyl alcohol-based resin solution and an aqueous boric acid solution were mixed so that 0.412 parts by weight of boric acid was added to 100 parts by weight of polyvinyl alcohol-based resin, and defoamed to obtain an aqueous solution for layer B.
• the obtained aqueous solution for layer A was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment, using a baker applicator so that the thickness after drying was 70 ⁇ m. and dried in a hot air circulating oven at 80° C. to remove moisture, and a layer A was produced on the PET film. Further, the obtained aqueous solution for layer B was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 280 ⁇ m, and the temperature was maintained at 80 ° C.
• PET polyethylene terephthalate
• Layers A and B were peeled off from the PET film, and layers A and B were laminated and bonded using a laminator to prepare a temporary protective material having a two-layer structure of A layer/B layer.
• Example 2 In the same manner as in Example 1, an aqueous solution for layer A and an aqueous solution for layer B were prepared.
• the obtained aqueous solution for layer A was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 140 ⁇ m, and the temperature was maintained at 80°C.
• PET polyethylene terephthalate
• the film was dried in an air circulating oven to remove water, and a layer A was produced on the PET film.
• aqueous solution for layer B was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 140 ⁇ m, and the temperature was maintained at 80 ° C. was dried in a hot air circulating oven to remove moisture, and a B layer was produced on the PET film. Since it is difficult to obtain a predetermined thickness for both the A layer and the B layer at once, coating and drying were repeated several times to obtain a predetermined thickness. Layers A and B were peeled off from the PET film, and layers A and B were laminated and bonded using a laminator to prepare a temporary protective material having a two-layer structure of A layer/B layer.
• PET polyethylene terephthalate
• Example 3 In the same manner as in Example 1, an aqueous solution for layer A and an aqueous solution for layer B were prepared.
• the obtained aqueous solution for layer A was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 25 ⁇ m, and the temperature was maintained at 80°C.
• PET polyethylene terephthalate
• the film was dried in an air circulating oven to remove water, and a layer A was produced on the PET film.
• Another layer A was prepared in the same manner.
• the obtained aqueous solution for layer B was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 250 ⁇ m, and the temperature was maintained at 80 ° C. was dried in a hot air circulating oven to remove moisture, and a B layer was produced on the PET film. Since it is difficult to obtain a predetermined thickness at once, coating and drying were repeated several times to obtain a predetermined thickness. Layers A, B, and A are peeled off from the PET film, and the layers A, B, and A are laminated in this order using a laminator and bonded together to form a three-layer structure of layer A/layer B/layer A. A temporary protective material was produced.
• PET polyethylene terephthalate
• Example 4 In the same manner as in Example 1, an aqueous solution for layer A and an aqueous solution for layer B were prepared.
• aqueous solution for A' layer After dissolving the polyvinyl alcohol-based resin in warm water of 90° C. or higher, the solution was cooled to room temperature to obtain an aqueous polyvinyl alcohol-based resin solution having a concentration of 20% by weight. PVA3 was used as the polyvinyl alcohol resin. Also, boric acid (B(OH) 3 ) was dissolved in water to obtain an aqueous cross-linking agent solution with a concentration of 3% by weight.
• aqueous polyvinyl alcohol-based resin solution and an aqueous boric acid solution were mixed so that the amount of boric acid was 2.811 parts by weight with respect to 100 parts by weight of polyvinyl alcohol-based resin, and defoamed to obtain an aqueous solution for layer A'.
• the obtained aqueous solution for layer A was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 20 ⁇ m, and the temperature was set at 80°C.
• PET polyethylene terephthalate
• the film was dried in an air circulating oven to remove water, and a layer A was produced on the PET film.
• the obtained aqueous solution for layer B was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 260 ⁇ m, and the temperature was maintained at 80 ° C.
• the obtained aqueous solution for layer A' was applied onto the non-release-treated surface of a polyethylene terephthalate (PET) film that had been subjected to release treatment on one side so that the thickness after drying was 20 ⁇ m.
• PET polyethylene terephthalate
• the film was dried in a hot air circulating oven at °C to remove water, and an A′ layer was produced on the PET film.
• Layers A, B, and A' are peeled off from the PET film, and layers A, B, and A' are laminated in this order using a laminator and laminated to form three layers: A layer/B layer/A' layer.
• a temporary protective material having a structure was produced.
• Example 5 In the same manner as in Example 1, an aqueous solution for layer A and an aqueous solution for layer B were prepared.
• the obtained aqueous solution for layer A was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 70 ⁇ m, and the temperature was set at 80°C.
• PET polyethylene terephthalate
• the film was dried in an air circulating oven to remove water, and a layer A was produced on the PET film.
• Another layer A was prepared in the same manner.
• the obtained aqueous solution for layer B was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 120 ⁇ m, and the temperature was maintained at 80 ° C. was dried in a hot air circulating oven to remove moisture, and a B layer was produced on the PET film.
• PET polyethylene terephthalate
• Another layer B was prepared in the same manner. Since it is difficult to obtain a predetermined thickness at once, coating and drying were repeated several times to obtain a predetermined thickness.
• a layer, B layer, A layer, and B layer are peeled off from the PET film, and the A layer, B layer, A layer, and B layer are laminated in this order using a laminator and laminated to form an A layer/B layer/A layer.
• a temporary protective material having a four-layer structure of /B layers was produced.
• Example 6 In the same manner as in Example 1, an aqueous solution for layer A and an aqueous solution for layer B were prepared. The obtained aqueous solution for layer A was coated on the non-release-treated side of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 200 ⁇ m, and the temperature was set at 80°C. The film was dried in an air circulating oven to remove water, and a layer A was produced on the PET film.
• PET polyethylene terephthalate
• aqueous solution for layer B was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 150 ⁇ m, and the temperature was maintained at 80 ° C. was dried in a hot air circulating oven to remove moisture, and a B layer was produced on the PET film. Since it is difficult to obtain a predetermined thickness for both the A layer and the B layer at once, coating and drying were repeated several times to obtain a predetermined thickness. Layers A and B were peeled off from the PET film, and layers A and B were laminated and bonded using a laminator to prepare a temporary protective material having a two-layer structure of A layer/B layer.
• PET polyethylene terephthalate
• Example 7 In the same manner as in Example 1, an aqueous solution for layer A and an aqueous solution for layer B were prepared. The obtained aqueous solution for layer A was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 30 ⁇ m, and the temperature was set at 80°C. The film was dried in an air circulating oven to remove water, and a layer A was produced on the PET film.
• PET polyethylene terephthalate
• the obtained aqueous solution for layer B was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 320 ⁇ m, and the temperature was maintained at 80 ° C. was dried in a hot air circulating oven to remove moisture, and a B layer was produced on the PET film. Since it is difficult to obtain a predetermined thickness at once, coating and drying were repeated several times to obtain a predetermined thickness. Layers A and B were peeled off from the PET film, and layers A and B were laminated and bonded using a laminator to prepare a temporary protective material having a two-layer structure of A layer/B layer.
• PET polyethylene terephthalate
• Example 8 Preparation of aqueous solution for layer A
• the solution was cooled to room temperature to obtain a 20% by weight polyvinyl alcohol-based resin aqueous solution.
• PVA1 was used as the polyvinyl alcohol resin.
• boric acid (B(OH) 3 ) was dissolved in water to obtain an aqueous boric acid solution with a concentration of 3% by weight.
• aqueous polyvinyl alcohol-based resin solution and an aqueous boric acid solution were mixed so that 0.251 parts by weight of boric acid was added to 100 parts by weight of polyvinyl alcohol-based resin, and defoamed to obtain an aqueous solution for layer A.
• the obtained aqueous solution for layer A was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 70 ⁇ m, and the temperature was set at 80°C.
• PET polyethylene terephthalate
• the film was dried in an air circulating oven to remove water, and a layer A was produced on the PET film.
• an aqueous solution for layer B was prepared.
• the obtained aqueous solution for layer B was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 280 ⁇ m, and the temperature was set at 80°C.
• the film was dried in an air circulating oven to remove water, and a B layer was produced on the PET film. Since it is difficult to obtain a predetermined thickness at once, coating and drying were repeated several times to obtain a predetermined thickness.
• Layers A and B were peeled off from the PET film, and layers A and B were laminated and bonded using a laminator to prepare a temporary protective material having a two-layer structure of A layer/B layer.
• Example 9 Preparation of aqueous solution for layer B
• the solution was cooled to room temperature to obtain a 20% by weight polyvinyl alcohol-based resin aqueous solution.
• PVA2 was used as the polyvinyl alcohol resin.
• boric acid (B(OH) 3 ) was dissolved in water to obtain an aqueous boric acid solution with a concentration of 3% by weight.
• aqueous polyvinyl alcohol-based resin solution and an aqueous boric acid solution were mixed so as to give 0.132 parts by weight of boric acid with respect to 100 parts by weight of polyvinyl alcohol-based resin, and defoamed to obtain an aqueous solution for layer B.
• An aqueous solution for layer A was prepared in the same manner as in Example 1.
• the obtained aqueous solution for layer A was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 70 ⁇ m, and the temperature was set at 80°C.
• the film was dried in an air circulating oven to remove water, and a layer A was produced on the PET film.
• the obtained aqueous solution for layer B was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 280 ⁇ m, and the temperature was maintained at 80 ° C.
• Layers A and B were peeled off from the PET film, and layers A and B were laminated and bonded using a laminator to prepare a temporary protective material having a two-layer structure of A layer/B layer.
• Example 10 An aqueous solution for layer A was prepared in the same manner as in Example 8. The obtained aqueous solution for layer A was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment, using a baker applicator so that the thickness after drying was 70 ⁇ m. and dried in a hot air circulating oven at 80° C. to remove moisture, and a layer A was produced on the PET film. Further, in the same manner as in Example 9, an aqueous solution for layer B was prepared.
• PET polyethylene terephthalate
• the obtained aqueous solution for layer B was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 280 ⁇ m, and the temperature was set at 80°C.
• PET polyethylene terephthalate
• the film was dried in an air circulating oven to remove water, and a B layer was produced on the PET film. Since it is difficult to obtain a predetermined thickness at once, coating and drying were repeated several times to obtain a predetermined thickness.
• Layers A and B were peeled off from the PET film, and layers A and B were laminated and bonded using a laminator to prepare a temporary protective material having a two-layer structure of A layer/B layer.
• the obtained aqueous solution for layer B was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 300 ⁇ m, and the temperature was set at 80°C. Moisture was removed by drying in an air circulating oven to prepare a temporary protective material of B layer single layer on the PET film. Since it is difficult to obtain a predetermined thickness at once, coating and drying were repeated several times to obtain a predetermined thickness.
• PET polyethylene terephthalate
• the obtained aqueous solution for layer A was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 300 ⁇ m, and the temperature was set at 80°C. Moisture was removed by drying in an air circulating oven to prepare a temporary protective material having a layer A single layer on the PET film. Since it is difficult to obtain a predetermined thickness at once, coating and drying were repeated several times to obtain a predetermined thickness.
• PET polyethylene terephthalate
• the obtained aqueous solution for layer A was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 350 ⁇ m, and the temperature was maintained at 80°C. Moisture was removed by drying in an air circulating oven to prepare a temporary protective material having a layer A single layer on the PET film.
• PET polyethylene terephthalate
• aqueous polyvinyl alcohol-based resin solution After dissolving the polyvinyl alcohol-based resin in warm water of 90° C. or higher, the solution was cooled to room temperature to obtain an aqueous polyvinyl alcohol-based resin solution having a concentration of 20% by weight. PVA4 was used as the polyvinyl alcohol resin. Also, boric acid (B(OH) 3 ) was dissolved in water to obtain an aqueous boric acid solution with a concentration of 3% by weight. An aqueous polyvinyl alcohol-based resin solution and an aqueous boric acid solution were mixed so as to give 0.294 parts by weight of boric acid with respect to 100 parts by weight of polyvinyl alcohol-based resin, and defoamed to obtain an aqueous solution for layer A'.
• B(OH) 3 boric acid
• the obtained aqueous solution for layer A was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 70 ⁇ m, and the temperature was set at 80°C.
• the film was dried in an air circulating oven to remove water, and a layer A was produced on the PET film.
• the obtained aqueous solution for layer A′ was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 280 ⁇ m.
• the film was dried in a hot air circulating oven at °C to remove water, and an A′ layer was produced on the PET film.
• Layers A and A' were peeled off from the PET film, and layers A and A' were laminated in this order using a laminator and bonded together to prepare a temporary protective material having a two-layer structure of layer A/layer A
• aqueous polyvinyl alcohol-based resin solution After dissolving the polyvinyl alcohol-based resin in warm water of 90° C. or higher, the solution was cooled to room temperature to obtain an aqueous polyvinyl alcohol-based resin solution having a concentration of 20% by weight. PVA5 was used as the polyvinyl alcohol resin. Also, boric acid (B(OH) 3 ) was dissolved in water to obtain an aqueous boric acid solution with a concentration of 3% by weight. An aqueous polyvinyl alcohol-based resin solution and an aqueous boric acid solution were mixed so as to give 0.984 parts by weight of boric acid with respect to 100 parts by weight of polyvinyl alcohol-based resin, and defoamed to obtain an aqueous solution for layer B.
• B(OH) 3 boric acid
• the obtained aqueous solution for layer A was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 70 ⁇ m, and the temperature was set at 80°C.
• the film was dried in an air circulating oven to remove water, and a layer A was produced on the PET film.
• the obtained aqueous solution for layer B was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 280 ⁇ m, and the temperature was maintained at 80 ° C.
• Layers A and B were peeled off from the PET film, and layers A and B were laminated and bonded using a laminator to prepare a temporary protective material having a two-layer structure of A layer/B layer.
• the obtained aqueous solution for layer A was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 70 ⁇ m, and the temperature was set at 80°C. Moisture was removed by drying in an air circulating oven to prepare a temporary protective material having a layer A single layer on the PET film.
• PET polyethylene terephthalate
• the obtained aqueous solution for layer B was coated on the non-release-treated surface of a polyethylene terephthalate (PET) film on one side of which was subjected to release treatment so that the thickness after drying was 280 ⁇ m, and the temperature was set at 80°C. Moisture was removed by drying in an air circulating oven to prepare a temporary protective material of B layer single layer on the PET film. Since it is difficult to obtain a predetermined thickness at once, coating and drying were repeated several times to obtain a predetermined thickness.
• PET polyethylene terephthalate
• Sd is the degree of saponification (mol%) of the polyvinyl alcohol resin constituting each layer
• Mw is the weight average molecular weight of the polyvinyl alcohol resin constituting each layer
• C is boric acid in each layer.
• the content (% by weight) of Gu is 70 and Gd is 5.
• the gel fraction (% by weight) was determined by calculating the ratio of the weight of the undissolved component to the initial weight of the test piece, and evaluated according to the following criteria. A high gel fraction in the 45 kHz ultrasonic dissolution test indicates excellent water resistance. ⁇ : The gel fraction was 70% by weight or more. x: The gel fraction was less than 70% by weight.
• the water temperature in the beaker set in the water bath was heated to 80°C, and when the water temperature stabilized at 80°C, the test piece was added. Fifteen minutes after the test piece was added, the beaker was removed from the water bath, filtered through a 200-mesh stainless steel wire mesh, and dried in an oven at 80°C together with the wire mesh.
• the weight of undissolved components was calculated from the difference between the weight of the wire mesh before filtration and the weight of the wire mesh after filtration and drying.
• the gel fraction (% by weight) was determined by calculating the ratio of the weight of the undissolved component to the initial weight of the test piece, and evaluated according to the following criteria. If the gel fraction in the 80° C. hot water dissolution test is low, it can be said that the removability with hot water is high. ⁇ : The gel fraction was 5% by weight or less. x: The gel fraction exceeded 5% by weight.
• Laminate suitability The obtained temporary protective material was allowed to stand for 72 hours in an environment of 23°C and 50% relative humidity to condition the humidity. Also, as an electronic substrate, ETT Co. , LTD. (Thailand) manufactured board ET-PCB-LQFP48 with 16 MLCCs of 0603 size soldered near the center was prepared. The humidity-conditioned temporary protective material was cut into a size of 45 mm ⁇ 45 mm, and pure water was thinly applied to the contact surface with the substrate with a brush, and then set on the prepared substrate. An electronic substrate and a temporary protective material were laminated and pressure-bonded under conditions of 100° C. ⁇ 30 minutes and 0.5 MPa.
• the pressure-bonded product was taken out, and the lamination state was visually observed using a magnifying glass of 4x magnification.
• ⁇ The temporary protective material was sufficiently adhered to the irregularities around the MLCC, and neither lifting nor peeling was observed at the edges of the substrate.
• ⁇ No lifting or peeling at the edge of the substrate was observed, but the unevenness around the MLCC was not sufficiently followed, and some gaps were observed.
• x Lifting and peeling were observed at the edges of the substrate.
• the substrate to which the temporary protective material was adhered was subjected to heat treatment in an oven at 180°C for 30 minutes while a surface load of 0.05 MPa was applied. Note that the surface load used was preheated to 180°C.
• the taken out substrate with the temporary protective material attached was slowly cooled in a desiccator. After 200 ml of pure water was placed in a 500 ml beaker, the substrate with the temporary protective material adhered was gradually cooled to room temperature, immersed in the beaker, and allowed to stand in an ultrasonic cleaner at 45 kHz for 10 minutes.
• the substrate was taken out from the beaker, the water was lightly wiped off, and the state of the temporary protective material on the surface was visually confirmed to evaluate the water resistance according to the following criteria.
• ⁇ There was no lifting or peeling at the edge of the substrate, and no problematic change was observed.
• ⁇ Lifting and peeling of the edge of the substrate, cracking of the temporary protective material, etc. were observed.
• x Cracking and peeling progressed, and a part of the temporary protective material fell off.
• a temporary protective material that has both water resistance that can protect the component mounting surface in the semiconductor substrate mounting process and deformability that can follow the components on the semiconductor substrate, and that is excellent in hot water removal.

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• 2022
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