Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D129/00—Coating compositions 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; Coating compositions based on hydrolysed polymers of esters of unsaturated alcohols with saturated carboxylic acids; Coating compositions based on derivatives of such polymers
  • C09D129/02—Homopolymers or copolymers of unsaturated alcohols
  • C09D129/04—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
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/20—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes for coatings strippable as coherent films, e.g. temporary coatings strippable as coherent films
• • 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 a temporary protective material and a temporary protective material solution.
• the electronic components When processing electronic components such as semiconductors, in order to facilitate handling of the electronic components and to prevent damage, the electronic components are protected by being fixed to a support plate via an adhesive composition or by attaching an adhesive tape to the electronic components.
• an adhesive composition For example, when a thick-film wafer cut from a high-purity silicon single crystal or the like is ground to a predetermined thickness to produce a thin-film wafer, the thick-film wafer is adhered to a support plate via an adhesive composition.
• Patent Document 1 discloses a method in which an adhesive is applied to the surface of a temporary holding substrate to form a temporary adhesive layer, a semiconductor wafer is adhered and fixed by embedding the tip portions of the bumps in this temporary adhesive layer, and then the temporary adhesive layer is dissolved with a solvent to detach the chip-type electronic components from the temporary holding substrate.
• Patent Document 2 discloses a configuration in which a protective layer is formed by covering the surface of a wafer with a liquid mixture of polyvinyl alcohol, sodium lauryl ether sulfate, and sodium ⁇ -olefin sulfonate.
• Patent Document 3 discloses a method for dividing a wafer in which a film containing a polyvinyl alcohol polymer having a degree of polymerization of 100 to 3000 and a degree of saponification of 70 to 99 mol % is laminated to a semiconductor wafer.
• Patent No. 4078760 Utility Model Registration No. 3221770 Patent No. 5563341
• 3D packaging has been adopted for electronic component packaging in order to increase the density and yield of integrated circuits.
• peripheral elements such as capacitors and solder balls are mounted all over the top and back surfaces of chip-type electronic components in addition to integrated circuits.
• peripheral elements may be placed on the back side before mounting an integrated circuit on the top side. In such a case, when mounting an integrated circuit on the top side, the elements on the back side may come into contact with the stage, etc., which may cause scratches or damage to the chip-type electronic components.
• a protective sheet is used to protect the elements that are to be mounted on the back side first, but such a protective sheet needs to be removed after arranging multiple integrated circuits on the front side in multiple layers.
• organic solvents or other chemicals are used for removal, there are problems such as increased environmental load and generation of protective sheet residue, and therefore a temporary protective material that can be removed in a short time using water at room temperature or low temperature is required.
• the present invention aims to provide a temporary protective material and a temporary protective material solution that can be easily removed with water at room temperature or low temperature.
• the present disclosure (1) relates to a temporary protective material used as a protective material during semiconductor manufacturing, the temporary protective material containing a polyvinyl alcohol-based resin including a modified polyvinyl alcohol-based resin, and having a gel fraction of 50% by weight or less when ultrasonic vibrations are applied for 3 minutes in water having a water temperature of 35 ⁇ 5°C at the start of ultrasonic application under conditions of a frequency of 45 ⁇ 5 kHz and an ultrasonic output of 100 ⁇ 10 W/2.5 ⁇ 0.5 L of water.
• the present disclosure (2) is the temporary protective material of the present disclosure (1), in which the modified polyvinyl alcohol-based resin has a structural unit having a polar group.
• the present disclosure (3) is the temporary protective material of the present disclosure (2), in which the polar group is a sulfonic acid group.
• the present disclosure (4) is the temporary protective material of any one of the present disclosures (1) to (3), in which the modified polyvinyl alcohol-based resin has a degree of saponification of 70 mol% or more and 100 mol% or less and an average degree of polymerization of 300 or more and 4,500 or less.
• the present disclosure (5) is the temporary protective material of any one of the present disclosures (1) to (4), in which the polyvinyl alcohol-based resin contains 50% by weight or more and 100% by weight or less of a modified polyvinyl alcohol-based resin.
• the present disclosure (6) is any one of the temporary protective materials of the present disclosure (1) to (5), which does not contain a crosslinking agent or has a crosslinking agent content of 0.1 wt % or less.
• the present disclosure (7) is the temporary protective material of the present disclosure (1) to (6), further comprising an alcohol compound, the alcohol compound having two or more hydroxyl groups and a hydroxyl value of 40 or less.
• the present disclosure (8) is the temporary protective material of the present disclosure (7), in which the content of the alcohol compound is 5% by weight or more and 50% by weight or less.
• the present disclosure (9) is a temporary protective material solution containing the temporary protective material of any one of the present disclosures (1) to (8) and a solvent containing water.
• the present disclosure (10) is a temporary protective material solution containing the temporary protective material of the present disclosure (6) and a solvent containing water. The present invention will be described in detail below.
• the inventors discovered that by making a temporary protective material that contains a modified polyvinyl alcohol resin and has a gel fraction of 50% by weight or less as measured by a specified method, it is possible to obtain a temporary protective material that can protect the component mounting surface during the mounting process of a semiconductor substrate and can be easily removed with low-temperature water, and thus completed the present invention.
• the temporary protective material of the present invention contains a polyvinyl alcohol-based resin.
• the polyvinyl alcohol resin includes a modified polyvinyl alcohol resin. By including the modified polyvinyl alcohol-based resin, the component mounting surface can be adequately protected in the mounting process of the semiconductor substrate, and a temporary protective material can be formed which can be easily removed with water.
• the degree of saponification of the polyvinyl alcohol resin is preferably 70 mol % or more and 100 mol % or less. By setting the content within the above range, a temporary protective material exhibiting water solubility suitable for cleaning can be obtained.
• the saponification degree is more preferably 80 mol % or more, even more preferably 85 mol % or more, and particularly preferably 91 mol % or more, and more preferably 99.9 mol % or less, even more preferably 99 mol % or less, and particularly preferably 97 mol % or less.
• the saponification degree can be measured, for example, by a method in accordance with JIS K 6726.
• the saponification degree indicates the ratio of units that are actually converted into vinyl alcohol units to vinyl ester units that can be converted into vinyl alcohol units by saponification.
• the degree of saponification can be controlled, for example, by adjusting the saponification conditions, that is, the hydrolysis conditions.
• the average polymerization degree of the polyvinyl alcohol resin is preferably 300 or more, more preferably 450 or more, even more preferably 600 or more, and particularly preferably 800 or more, and is preferably 4,500 or less, more preferably 3,000 or less, even more preferably 2,000 or less, and particularly preferably 1,500 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 in accordance with JIS K6726.
• the polyvinyl alcohol-based resin may contain the modified polyvinyl alcohol-based resin, and may be a mixed resin of a plurality of modified polyvinyl alcohol-based resins having different compositions, or may be a mixed resin of a modified polyvinyl alcohol-based resin and an unmodified polyvinyl alcohol-based resin.
• the saponification degree can be determined by multiplying the content (% by weight) of each polyvinyl alcohol-based resin in the polyvinyl alcohol-based resin by the saponification degree (% by mole), dividing the product by 100, and then adding up the product.
• the weight average molecular weight, number average molecular weight, and average degree of polymerization of the mixed resin can be calculated by multiplying each value by the content (weight %) of each polyvinyl alcohol-based resin in the polyvinyl alcohol-based resin, dividing the product by 100, and then adding up the results.
• the polyvinyl alcohol resin includes a modified polyvinyl alcohol resin.
• the modified polyvinyl alcohol resin preferably has a structural unit having a polar group.
• Examples of the polar group include a sulfonic acid group, a pyrrolidone ring group, an amino group, an amide group, and a carboxyl group.
• a sulfonic acid group is preferred because it is easier to remove with water.
• an example of a structural unit having a sulfonic acid group is a structural unit represented by the following formula (1).
• R 1 and R 2 each independently represent an alkylene group having 0 to 4 carbon atoms, an amide group (-CONH-), an ester group (-COO-) or an ether group (-O-), and X 1 represents a hydrogen atom, a metal atom or an alkyl group having 1 to 3 carbon atoms.
• alkylene group having 0 to 4 carbon atoms examples include single bonds, linear alkylene groups such as methylene, ethylene, trimethylene, and tetramethylene groups, and branched alkylene groups such as propylene (1-methylethylene, 2-methylethylene), butylene (1-ethylethylene, 2-ethylethylene), 1,2-dimethylethylene, 2,2-dimethylethylene, 1-methyltrimethylene, 2-methyltrimethylene, and 3-methyltrimethylene groups. Of these, the 2,2-dimethylethylene group is preferred.
• X1 represents a hydrogen atom, a metal atom, or an alkyl group having 1 to 3 carbon atoms.
• the metal atom include a sodium atom, a lithium atom, and a potassium atom, and among these, a sodium atom is preferable.
• the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, and a propyl group.
• the above X1 is preferably a metal atom, more preferably a sodium atom.
• the structural unit having the above sulfonic acid group is preferably a structural unit having a salt of a sulfonic acid group represented by the following formula (1-1).
• R 3 represents an alkylene group having 0 to 4 carbon atoms, and among these, a 2,2-dimethylethylene group is preferable.
• an example of a structural unit having a pyrrolidone ring group is a structural unit represented by the following formula (2).
• a structural unit having the amino group is a structural unit represented by the following formula (3).
• R 4 represents a single bond or an alkylene group having 1 to 10 carbon atoms
• R 5 and R 6 represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.
• the alkylene group having 1 to 10 carbon atoms includes a linear alkylene group, a branched alkylene group, and a cyclic alkylene group.
• the linear alkylene group include a methylene group, a vinylene group, an n-propylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, an octamethylene group, and a decamethylene group.
• Examples of the branched alkylene group include a methylmethylene group, a methylethylene group, a 1-methylpentylene group, and a 1,4-dimethylbutylene group.
• cyclic alkylene group examples include a cyclopropylene group, a cyclobutylene group, and a cyclohexylene group. Of these, linear alkylene groups are preferred, methylene, vinylene and n-propylene groups are more preferred, and methylene and vinylene groups are even more preferred.
• alkyl group having 1 to 10 carbon atoms examples include linear alkyl groups such as methyl, ethyl, propyl, n-butyl, n-pentyl, n-heptyl, n-octyl, n-nonyl, and n-decyl groups; branched alkyl groups such as isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2,2-dimethylpropyl, 1,1,3,3-tetramethylbutyl, and 2-ethylhexyl groups; and cycloalkyl groups such as cyclopropyl, cyclopropylmethyl, cyclobutyl, cyclopentyl, and cyclohexyl groups.
• linear alkyl groups such as methyl, ethyl, propyl, n-butyl, n-pentyl, n-heptyl,
• an example of a structural unit having the amide group is a structural unit represented by the following formula (4).
• R 7 represents an alkylene group having 1 to 10 carbon atoms
• R 8 represents an alkyl group having 1 to 10 carbon atoms.
• Examples of the alkylene group having 1 to 10 carbon atoms include the same as R 4 in the above formula (3).
• Examples of the alkyl group having 1 to 10 carbon atoms include the same as R 5 and R 6 in the above formula (3).
• the content of structural units having a polar group in the modified polyvinyl alcohol resin is preferably 1 mol% or more, more preferably 3 mol% or more, and particularly preferably 5 mol% or more, and 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 having a polar group can be measured, for example, by NMR.
• the saponification degree of the modified polyvinyl alcohol resin is preferably 70 mol % or more and 100 mol % or less. By setting the content within the above range, it is possible to impart sufficient strength and hardness as a temporary protective material, and also to achieve a high level of water resistance and washability at the same time.
• the saponification degree is more preferably 80 mol% or more, even more preferably 85 mol% or more, even more preferably 90 mol% or more, particularly preferably 95 mol% or more, more preferably 99.9 mol% or less, even more preferably 99 mol% or less, particularly preferably 98 mol% or less.
• the average polymerization degree of the modified polyvinyl alcohol resin is preferably 300 or more, more preferably 500 or more, even more preferably 700 or more, and particularly preferably 900 or more, and is preferably 4500 or less, more preferably 3000 or less, even more preferably 2000 or less, and particularly preferably 1500 or less.
• the content of the structural unit having the polar group in the polyvinyl alcohol resin is preferably 1 mol% or more, more preferably 2 mol% or more, and even more preferably 3.5 mol% or more, and is preferably 20 mol% or less, more preferably 15 mol% or less, and even more preferably 10 mol% or less.
• the content of the structural unit having a polar group can be determined by multiplying the content (wt %) of each polyvinyl alcohol-based resin in the polyvinyl alcohol-based resin by the content (mol %) of the structural unit having a polar group, dividing the product by 100, and then adding up the total.
• the content of the modified polyvinyl alcohol resin in the polyvinyl alcohol resin is preferably 5% by weight or more, more preferably 25% by weight or more, even more preferably 50% by weight or more, and particularly preferably 85% by weight or more, from the viewpoint of removability with water.
• the upper limit is 100% by weight.
• the content of the modified polyvinyl alcohol resin in the temporary protective material of the present invention is preferably 50% by weight or more, more preferably 70% by weight or more, even more preferably 85% by weight or more, and preferably 100% by weight or less, more preferably 95% by weight or less, even more preferably 90% by weight or less.
• the content of the polyvinyl alcohol-based resin is preferably 50% by weight or more, more preferably 75% by weight or more, even more preferably 85% by weight or more, and preferably 100% by weight or less, more preferably 95% by weight or less, even more preferably 90% by weight or less.
• the polyvinyl alcohol resin is obtained by polymerizing a vinyl ester to obtain a polymer, and then saponifying, i.e., hydrolyzing, the polymer according to a conventionally known method.
• An alkali or an acid is generally used as the saponification catalyst.
• vinyl esters examples include vinyl acetate, vinyl formate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl versatate, vinyl laurate, vinyl stearate, and vinyl benzoate.
• the method for polymerizing vinyl esters is not particularly limited, but examples include solution polymerization, bulk polymerization, and suspension polymerization.
• polymerization catalysts used in polymerizing the vinyl esters include 2-ethylhexyl peroxydicarbonate (Trigonox EHP, manufactured by Tianjin McEIT), 2,2'-azobisisobutyronitrile (AIBN), t-butyl peroxyneodecanoate, bis(4-t-butylcyclohexyl) peroxydicarbonate, di-n-propyl peroxydicarbonate, di-n-butyl peroxydicarbonate, di-cetyl peroxydicarbonate, and di-s-butyl peroxydicarbonate. Only one of the above polymerization catalysts may be used, or two or more of them may be used in combination.
• the polyvinyl alcohol resin may be a saponified polymer of a vinyl ester and another unsaturated monomer.
• the other unsaturated monomers include monomers other than the vinyl esters and having an unsaturated double bond such as a vinyl group. Specific examples include olefins, (meth)acrylic acid and salts thereof, (meth)acrylic acid esters, unsaturated acids other than (meth)acrylic acid, salts and esters thereof, (meth)acrylamides, N-vinyl amides, vinyl ethers, nitriles, vinyl halides, allyl compounds, vinyl silyl compounds, isopropenyl acetate, sulfonic acid group-containing compounds, and amino group-containing compounds.
• Examples of the olefins include ethylene, propylene, 1-butene, and isobutene.
• examples of the (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate.
• Examples of unsaturated acids other than (meth)acrylic acid, and their salts and esters include maleic acid and its salts, maleic acid esters, itaconic acid and its salts, itaconic acid esters, methylenemalonic acid and its salts, and methylenemalonic acid esters.
• Examples of (meth)acrylamides include acrylamide, n-methylacrylamide, N-ethylacrylamide, N,N-dimethylacrylamide, etc.
• Examples of N-vinylamides include N-vinylpyrrolidone, etc.
• vinyl ethers include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl ether, n-butyl vinyl ether, etc.
• the nitriles include (meth)acrylonitrile, etc.
• the vinyl halides include vinyl chloride and vinylidene chloride, etc.
• the allyl compounds include allyl acetate and allyl chloride, etc.
• the vinylsilyl compounds include vinyltrimethoxysilane, etc.
• Examples of the sulfonic acid group-containing compound include (meth)acrylamidealkanesulfonic acids such as (meth)acrylamidepropanesulfonic acids (e.g., 2-acrylamide-2-methylpropanesulfonic acid) and salts thereof; and olefinsulfonic acids such as ethylenesulfonic acid, allylsulfonic acid, and methallylsulfonic acid and salts thereof.
• the amino group-containing compound include allylamine, polyoxyethylene allylamine, polyoxypropylene allylamine, polyoxyethylene vinylamine, and polyoxypropylene vinylamine.
• the temporary protective material of the present invention may further contain an alcohol compound.
• the alcohol compound has two or more hydroxyl groups. By including the alcohol compound, the removability with water can be further improved.
• the alcohol compound is different from the organic solvent.
• the hydroxyl value of the alcohol compound is preferably 40 or less, more preferably 36 or less, and particularly preferably 33 or less. There is no particular lower limit, but it is preferably 18 or more, and more preferably 25 or more.
• the hydroxyl value is a value obtained by dividing the molecular weight of the alcohol compound by the number of hydroxyl groups in one molecule.
• the hydroxyl value can be determined by multiplying the content (wt%) of each alcohol compound in the entire alcohol compound by the hydroxyl value, dividing the product by 100, and then adding up the product.
• Examples of the alcohol compounds include glycols, glycerins, sugar alcohols, and the like.
• Examples of the glycols include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, isoprene glycol, 1,3-butylene glycol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol, and 1,2-decanediol.
• Examples of the glycerins include glycerin, diglycerin, and polyglycerin.
• sugar alcohol examples include xylitol, trehalose, maltitol, mannitol, sorbitol, erythritol, arabitol, ribitol, galactitol, glucitol, and raffinose.
• glycerins and sugar alcohols are preferred, and glycerin, erythritol, and xylitol are more preferred.
• the content of the above alcohol compound is preferably 1% by weight or more, more preferably 3% by weight or more, even more preferably 5% by weight or more, particularly preferably 10% by weight or more, preferably 50% by weight or less, more preferably 30% by weight or less, and even more preferably 15% by weight or less, from the viewpoint of removability with water.
• the temporary protective material of the present invention may contain a crosslinking agent, but preferably does not contain a crosslinking agent.
• the crosslinking agent may be, for example, an oxoacid, a boron compound, a diamine, a polyamine, or the like. It may also be a metal salt of the acid.
• the oxoacid examples include boric acid, polycarboxylic acid, and hydroxycarboxylic acid.
• the polycarboxylic acid is an acid having two or more carboxyl groups
• the hydroxycarboxylic acid is preferably an acid having two or more carboxyl groups.
• Metal salts of the acids may also be used.
• boric acid examples include orthoboric acid, metaboric acid, and tetraboric acid.
• the boron compound may be, for example, a salt of boric acid other than the boric acid exemplified as the oxo acid.
• the boron compound may be a hydrate.
• the salt of boric acid may be an alkali metal salt such as borax, an alkaline earth metal salt such as calcium salt, or an organic amine salt such as triethylamine.
• alkali metal salt such as borax
• alkaline earth metal salt such as calcium salt
• organic amine salt such as triethylamine.
• polycarboxylic acid include oxalic acid, malonic acid, succinic acid, and phthalic acid.
• Examples of the hydroxycarboxylic acid include tartronic acid, malic acid, tartaric acid, citramalic acid, citric acid, and isocitric acid.
• the content of the above-mentioned crosslinking agent in the temporary protective material of the present invention is preferably 0.1% by weight or less, and more preferably 0% by weight, from the viewpoint of removability with water.
• the temporary protective material of the present invention may contain other components such as storage stabilizers, mechanical property improvers, thickeners, preservatives, antifungal agents, dispersion stabilizers, surfactants, spacers (gap adjustment materials), etc., as necessary, but it is preferable that the main components consist of a polyvinyl alcohol resin and a crosslinking agent.
• the temporary protective material of the present invention has a gel fraction of 50% by weight or less when ultrasonic vibrations are applied for 3 minutes in water having a water temperature of 35 ⁇ 5°C at the start of ultrasonic application under conditions of a frequency of 45 ⁇ 5 kHz and an ultrasonic output of 100 ⁇ 10 W/2.5 ⁇ 0.5 L of water. If the gel fraction is 50% by weight or less, excellent removability with water can be achieved.
• the gel fraction is preferably 30% by weight or less, more preferably 10% by weight or less, even more preferably 5% by weight or less, and particularly preferably 3% by weight or less. Since the gel fraction is preferably as low as possible from the viewpoint of improving cleaning properties, the preferred lower limit is not particularly limited, but is substantially 0% by weight or more.
• the gel fraction of the temporary protective material of the present invention is preferably as low as possible, but may be increased by additives added for the purpose of improving the moisture resistance of the protective film or for other various purposes.
• the gel fraction may be increased by adding polyvalent carboxylic acid or polyvalent metal ion as a preservative when the temporary protective material solution is prepared, or by adding a surfactant for the purpose of improving washability. Even in such a case, it is important to keep the gel fraction within the above range, but it is generally possible to control the gel fraction by controlling the amount of addition.
• boric acid is a typical crosslinking agent for polyvinyl alcohol resins, and by making the molar ratio of boric acid to polyvinyl alcohol resin less than 1, the crosslinking coefficient can be made less than 1, and gelation can be prevented.
• the crosslinking coefficient that can achieve a gel fraction of 50% by weight or less varies depending on the system, so it cannot be said in general, but since the gel fraction rapidly decreases with the decrease in the crosslinking coefficient, if the content of the crosslinking agent is 0.1% by weight or less, in most cases, the crosslinking coefficient is significantly less than 1, and the gel fraction can be controlled to 50% by weight or less.
• the above-mentioned gel fraction can be obtained by applying the temporary protective material of the present invention, drying and molding to obtain a molded body, immersing the body in water having a water temperature of 35 ⁇ 5°C at the start of application of ultrasonic waves, stirring and dissolving the body using an ultrasonic cleaner, measuring the weight of the undissolved components, and calculating the ratio of the weight of the undissolved components to the weight of the molded body before immersion.
• a predetermined weight that can be measured as the dry weight of the temporary protective material may be collected, and ultrasonic waves may be applied as described above to determine the gel fraction.
• the composition may be brittle and unable to maintain its shape by itself.
• the frequency of the applied ultrasonic waves is appropriately selected within the range of 45 ⁇ 5 kHz, taking into consideration the cleaning performance and damage to the object to be cleaned. An example is 45 kHz.
• the cleaning power is improved, but the load on the object to be cleaned increases, while at higher frequencies the cleaning power is somewhat reduced, but the load on the object to be cleaned decreases.
• the ultrasonic output is appropriately selected within the range of 100 ⁇ 10 W/2.5 ⁇ 0.5 L of water, and an example is 100 W/2.5 L of water.
• the temporary protective material of the present invention can be removed within one minute when it is applied to a silicon wafer that has been subjected to a passivation treatment to a thickness of 1 ⁇ m to form a protective film, and then shower cleaning is performed by spraying pure water at 20° C.
• the coating method include casting, roll coating, lip coating, spin coating, screen coating, fountain coating, dipping, and spraying.
• the drying method include a method of natural drying and a method of drying by heating at a temperature equal to or lower than the glass transition temperature of the polyvinyl alcohol-based resin.
• Methods for spraying pure water include, for example, a method using a general manual or electric sprayer, as well as a method using a simple device combining a water flow pump and a spray nozzle.
• the passivation process refers to oxidizing the surface of metals and the like to make them passivated.
• passivation refers to coating the surface of an element with a passive film to prevent the surface from being affected by the outside air and from attracting dust.
• the surface is protected by a quartz film (SiO 2 ) or glass layer that is automatically formed during the manufacturing process, but it is common to further coat the surface with silicon nitride (SiN) by CVD (chemical vapor deposition) before dicing.
• the method for producing the temporary protective material of the present invention is not particularly limited, and examples thereof include a method in which a polyvinyl alcohol-based resin including a modified polyvinyl alcohol-based resin having a polar group, a solvent including water, and additives such as an alcohol compound are mixed to prepare a temporary protective material solution, which is then coated and dried.
• the temporary protective material solution further contains a solvent in addition to the components of the temporary protective material of the present invention.
• the present invention also includes the temporary protective material of the present invention and a temporary protective material solution containing a solvent including water.
• the temporary protective material solution of the present invention contains a solvent.
• the solvent includes water.
• the solvent content in the temporary protective material solution of the present invention is preferably 75% by weight or more, more preferably 85% by weight or more, particularly preferably 88% by weight or more, preferably 98% by weight or less, more preferably 96% by weight or less, particularly preferably 94% by weight or less.
• the water content in the above solvent is preferably 50% by weight or more, more preferably 60% by weight or more, even more preferably 80% by weight or more, and preferably 100% by weight or less, more preferably 95% by weight or less, even more preferably 90% by weight or less.
• the solvent may include an organic solvent.
• an organic solvent examples include alcohols such as methanol, ethanol, and isopropanol, and ketones such as acetone and methyl ethyl ketone.
• the content of the organic solvent in the above solvent is preferably 0% by weight or more, more preferably 5% by weight or more, even more preferably 10% by weight or more, and preferably 50% by weight or less, more preferably 40% by weight or less, even more preferably 20% by weight or less.
• 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 parts such as semiconductor devices and display devices.
• the temporary protective material of the present invention can be used to protect the component mounting surface by applying a temporary protective material solution of the present invention to the component mounting surface and drying it to form a protective film, which can be easily removed with water.
• Examples of methods for applying the temporary protective material solution of the present invention include casting, roll coating, lip coating, spin coating, screen coating, fountain coating, dipping, and spraying.
• Examples of the drying method include a method of natural drying and a method of drying by heating at a temperature equal to or lower than the glass transition temperature of the polyvinyl alcohol-based resin.
• the present invention provides a temporary protective material and a temporary protective material solution that can be easily removed with water at room temperature or low temperature.
• Example 1 is a photograph showing the cleaning properties of the temporary protective material obtained in Example 1.
• Example 1 is a photograph showing the cleaning properties of the temporary protective material obtained in Comparative Example 1.
• Example 1 A temporary protective material solution was prepared by dissolving 100 parts by weight of a polyvinyl alcohol resin in 900 parts by weight of water.
• the polyvinyl alcohol resin used was a modified polyvinyl alcohol resin PVA-A (saponification degree 95.4 mol%, average polymerization degree 1200, content of sulfonic acid group-containing structural units 4 mol%) having a structural unit having a sulfonic acid group represented by the following formula (1-1-1).
• the saponification degree of the polyvinyl alcohol resin was measured by a method in accordance with JIS K6726.
• the average polymerization degree of the polyvinyl alcohol resin was determined by measuring the viscosity of an aqueous solution in accordance with JIS K6726. Furthermore, the content of the structural unit having a sulfonic acid group was measured using 13 C-NMR.
• Example 2 to 10 Comparative Example 1
• a temporary protective material solution was prepared in the same manner as in Example 1, except that the polyvinyl alcohol-based resin, the alcohol compound, and the type and content of the solvent were as shown in Table 1.
• the polyvinyl alcohol resin in addition to PVA-A, an unmodified polyvinyl alcohol resin PVA-B (saponification degree 88 mol %, average polymerization degree 600) was used.
• the obtained temporary protective material solution was applied to a polyethylene terephthalate (PET) film that had been subjected to a release treatment using a Baker-type applicator so that the thickness after drying would be 20 ⁇ m, and the solution was dried in a hot air circulating oven at 80° C. to remove the solvent, and a molded body (temporary protective material) was produced on the PET film.
• PET polyethylene terephthalate
• the molded body was peeled off from the PET film and cut to 5 cm ⁇ 5 cm to produce a test piece, and the initial weight was measured.
• the obtained temporary protective material solution was applied onto a substrate (a test silicon wafer passivated with silicon nitride) using a spin coater so that the thickness after drying would be 1 ⁇ m, and the substrate was dried by leaving it to stand in an oven at 80° C. for 30 minutes to form a protective film (temporary protective material).
• the obtained protective film was sprayed with 10°C pure water at 280 g/min using a sprayer (Koshin battery-powered sprayer 3LGT-3S) from a distance of 10 cm from the protective film, and after 10 seconds, the water droplets on the surface were immediately removed with an air duster to check whether there was any remaining protective film.
• the present invention provides a temporary protective material and a temporary protective material solution that can be easily removed with water at room temperature or low temperature.

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• 2024
  • 2024-07-18 KR KR1020257033779A patent/KR20260042344A/ko active Pending
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