JP6516053B1 - Flux, core solder and soldering method - Google Patents

Abstract

The present invention provides a flux which is low in residue and excellent in processability, and core solder, flux coat solder and soldering method using this flux. A flux contains 70 wt% to 99.5 wt% of a solid solvent, and 0.5 wt% to 30 wt% of an activator. Further, the flux contains 70 wt% or more and 100 wt% or less of the phenolic solid solvent, and 0 wt% or more and 30 wt% or less of the activator. Furthermore, the flux contains more than 0 wt% to 30 wt% or less of a phenolic solid solvent, 70 wt% to 99.5 wt% of a solid solvent other than a phenolic solid solvent, and 0 wt% to 30 wt% of an activator. 【Selection chart】 None

Description

The present invention, the flux for solder cored, 及 Bihanda with a method of solder cored using a flux for solder fall into this killing.

  In general, the flux used for soldering chemically removes the metal oxides present on the metal surface of the soldering object to be soldered and allows the movement of metal elements at the boundary between the two. Have the effect of For this reason, by soldering using a flux, an intermetallic compound can be formed between the solder and the metal surface of the bonding object, and a strong bonding can be obtained.

  As a solder used in soldering, a solder called flux cored solder filled with linear solder is known. The flux which assumes that it is used by such a core solder is proposed (for example, refer to patent documents 1).

  The flux used in the core solder is required to be in the form of solid or liquid even in the form of high viscosity in terms of processability.

  As a soldering method using core solder, it is known to use a heating member called a soldering iron. On the other hand, a technique has been proposed in which a through hole is provided on a central axis of a soldering iron, and solder is supplied by entering the through hole into the through hole to perform soldering (for example, see Patent Document 2). Further, in the flux used in the soldering iron described in Patent Document 2, in order to solve a soldering defect caused by the carbonized residual flux residue, a low residue is made with a rosin-based flux. A technology that has been realized has been proposed (see, for example, Patent Document 3).

JP, 2017-113776, A JP, 2009-195938, A Unexamined-Japanese-Patent No. 2018-61978

  The flux used in the core solder is required to have a predetermined viscosity so as not to flow out of the solder at normal temperature, and conventionally, the flux contains a predetermined amount of rosin. Rosin is difficult to volatilize due to the heat history assumed in soldering, and becomes a main component of the residue.

  When soldering is performed using a soldering iron as described in Patent Document 2, the flux of solder supplied to the through hole may become a residue after heating and adhere to the inner surface of the through hole. . In the soldering using the soldering iron described in Patent Document 2, the core solder is supplied to the through hole while the soldering iron is controlled to maintain a predetermined temperature exceeding the melting point of the solder. Soldering takes place continuously. As a result, deposits such as residue continue to be heated and become carbides, causing charring in the through holes. Then, carbide may be deposited in the through hole of the soldering iron, the diameter of the through hole may be reduced, and the solder may not be supplied. In the flux described in Patent Document 3, low residue is realized by the selection of rosin. However, at the time of heating, it has been required to secure fluidity more quickly than when using rosin.

The present invention has been made to solve such problems, the flux for cored solder excellent killing a low residue and processability, solder cored using a flux for solder enters the arrows an object of the present invention is to provide a 及 Bihanda with method.

  The solid solvent and the phenolic solid solvent can make the flux have a predetermined viscosity, and are hardly volatile when heated to the temperature range assumed for soldering, and the effect of removing metal oxides is obtained. Furthermore, it has been found that the heat history assumed in soldering is volatile, and carbonization in continuous heating is suppressed.

Therefore, the present invention uses a core solder made of flux-filled solder, and heats the core solder with a soldering iron to a temperature exceeding the melting point of the solder to heat the object to be joined. A soldering method for melting the solder, wherein the soldering iron is supplied with the solder in the through hole formed along the central axis, and the temperature of the soldering iron exceeds the melting point of the solder For solid core solder containing 70 wt% to 99.5 wt% of solid solvent and 0.5 wt% to 30 wt% of activator used in the soldering method of heating and heating the core solder supplied to the through holes. It is a flux.

Further, the present invention uses a core solder made of flux-filled solder, and heats the core solder with a soldering iron to a temperature exceeding the melting point of the solder to heat the object to be joined. A soldering method for melting the solder, wherein the soldering iron is supplied with the solder in the through hole formed along the central axis, and the temperature of the soldering iron exceeds the melting point of the solder Flux for flux core solder containing 70 wt% or more and 100 wt% or less of phenolic solid solvent and 0 wt% or more and 30 wt% or less of activator used in the soldering method of heating and heating core solder supplied to through holes. It is.

Furthermore, the present invention uses a core solder consisting of solder filled with flux, and heats the core solder with a soldering iron to a temperature exceeding the melting point of the solder to heat the object to be joined. A soldering method for melting the solder, wherein the soldering iron is supplied with the solder in the through hole formed along the central axis, and the temperature of the soldering iron exceeds the melting point of the solder More than 0 wt% of a phenolic solid solvent used for the soldering method of heating and heating the cored solder supplied to the through holes, and 70 wt% or more and 99.5 wt% or less of solid solvents other than phenolic solid solvents It is a flux for a core solder containing 0 wt% or more and 30 wt% or less of an activator.

  In the present invention, the flux is preferably a solid at 25 ° C. or a liquid having a viscosity of 3500 Pa · s or more. The activator is any of an organic acid, an amine, an organic halogen compound, an amine hydrohalide, or a combination of two or more of an organic acid, an amine, an organic halogen compound, and an amine hydrohalide. Is preferred.

Furthermore, the present invention provides a flux for solder cored described above is solder cored filled in the solder.

Further, the present invention, 70 wt% or more 99.5 wt% of solid solvent below using solder enters the active agent consisting of solder flux has been filled, including more than 0.5 wt% 30 wt% or less killing, No it is to a temperature above the melting point, the solder cored by heating with a soldering iron, as well as heating the bonding target, the soldering method of melting the solder cored, soldering iron, along the central axis formed A solder is supplied to the through holes, and the soldering iron maintains a temperature exceeding the melting point of the solder, and heats the solder supplied to the through holes .

Furthermore, the present invention is a phenol-based solid solvent 70 wt% or more 100 wt% or less, the active agent using a cored solder comprising killing of solder flux has been filled, including more than 0 wt% 30 wt% or less, does Dano melting point to a temperature above the solder cored by heating with a soldering iron, as well as heating the bonding target, the soldering method of melting the solder cored, soldering iron is formed along the central axis The solder is supplied to the through hole, and the soldering iron maintains the temperature exceeding the melting point of the solder and heats the solder supplied to the through hole .

Furthermore, the present invention is filled with a flux containing more than 0 wt% of phenolic solid solvent and not more than 30 wt%, solid solvent other than phenolic solid solvent of 70 wt% to 99.5 wt%, and activator of 0 wt% to 30 wt%. by using a solder enters made of solder arrow, the solder to a temperature above the melting point of solder, the solder cored by heating with a soldering iron, as well as heating the bonding target, to melt the solder cored In the soldering method , the soldering iron is supplied into the through holes formed along the central axis, and the solder is supplied, the soldering iron maintains a temperature exceeding the melting point of the solder, and the welding iron is supplied to the through holes. It is a soldering method which heats a solder .

  The solid solvent or the phenolic solid solvent, or the flux containing the solid solvent and the phenolic solid solvent is in a form having a solid or a predetermined viscosity at normal temperature.

  In addition, when it does not contain a phenolic solid solvent, it contains an activator, and when it contains a phenolic solid solvent, it has sufficient activity for metal oxides without containing any activator, and solder In the process of heating to a temperature range exceeding the melting point of the above, the viscosity of the solid solvent and the phenolic solid solvent decreases and flows.

Thus, in the present invention, using OJ solder cored, it is possible to obtain sufficient activity for removing metal oxides. Moreover, since it does not flow at normal temperature, it is suitable as a flux of core solder. Furthermore, solid solvents and phenolic solid solvents are suitable for low-residue applications because they have volatility with the heat history assumed for soldering.

It is explanatory drawing which shows an example of the soldering iron used by the soldering method of this Embodiment. It is an explanatory view showing a soldering method of this embodiment. It is an explanatory view showing a soldering method of this embodiment. It is an explanatory view showing a soldering method of this embodiment. It is an explanatory view showing a soldering method of this embodiment.

<An example of the flux of the present embodiment>
The flux of the present embodiment includes a solid solvent or a phenolic solid solvent, or a solid solvent and a phenolic solid solvent.

  The flux containing the solid solvent has a predetermined viscosity such that it does not solidify or flow out at normal temperature. Further, even a flux containing a phenolic solid solvent has a predetermined viscosity such that it does not solidify or flow out at normal temperature. Furthermore, solid solvents and phenolic solid solvents whose boiling points are close to the temperature range assumed for soldering have volatility with a heat history assumed for soldering.

  A flux containing such a solid solvent has a function of removing metal oxides by containing an activator such as an organic acid. In addition, the phenolic solid solvent can also function as an activator. Thus, the flux containing a phenolic solid solvent has a function of removing metal oxides without containing other activators such as organic acids.

  In a solder filled with flux, the flux is required to have a predetermined viscosity to prevent the flux from flowing out of the solder. When the flux of the present embodiment is applied to core solder, if the amount of solid solvent is small, it is necessary to increase the amount of rosin in order to secure the viscosity. However, rosin is hardly volatile when heated to the temperature range assumed for soldering, and the amount of residue increases as the amount of rosin increases, and is not suitable for low residue applications.

  Therefore, the flux according to the first embodiment includes 70 wt% or more and 99.5 wt% or less of the solid solvent, and 0.5 wt% or more and 30 wt% or less of the activator.

  When the flux contains a phenolic solid solvent, it can function as a flux without containing an activator. Therefore, the flux of the second embodiment includes 70 wt% or more and 100 wt% or less of the phenolic solid solvent, and 0 wt% or more and 30 wt% or less of the activator.

  The flux according to the third embodiment includes 70 wt% to 99.5 wt% of the solid solvent, more than 0 wt% to 30 wt% of the phenolic solid solvent, and 0 wt% to 30 wt% of the activator. The flux of each embodiment is preferably a solid at 25 ° C. or a liquid having a viscosity of 3500 Pa · s or more.

  Examples of solid solvents include neopentyl glycol (2,2-dimethyl-1,3-propanediol), dioxane glycol and the like. Moreover, 4- (1,1,3,3-tetramethyl butyl) phenol, catechol etc. are mentioned as a phenol type solid solvent.

  The flux of each embodiment may contain 0 wt% or more and 30 wt% or less of rosin. Moreover, the flux of each embodiment contains 0 wt% or more and 30 wt% or less of an organic acid, 0 wt% or more and 5 wt% or less of an amine as an activator, and 0 wt% or more and 4 wt% or less of an amine hydrohalide salt And 0 wt% or more and 10 wt% or less. When an organic acid and an amine are added to the flux, a predetermined amount of the organic acid and the amine react to form a salt. Therefore, the reaction between the organic acid and the amine may be suppressed by adding two or more of the organic acid and the amine to be in the form of a salt and then adding them.

  Furthermore, the flux of each embodiment contains 0 wt% or more and 5 wt% of silicone, 0 wt% or more and 10 wt% or less of organic phosphorus compound, and 0 wt% or more and 3 wt% or less of an antifoaming agent as additives. It may further contain a surfactant and a colorant.

  Rosins include, for example, natural rosins such as gum rosin, wood rosins and tall oil rosins, and derivatives obtained from natural rosins. Examples of rosin derivatives include purified rosin, polymerized rosin, hydrogenated rosin, disproportionated rosin, hydrogenated disproportionated rosin, acid modified rosin, phenol modified rosin and α, β unsaturated carboxylic acid modified product (acrylated rosin Maleated rosins, fumarized rosins, etc.), and purified products, hydrides and disproportionates, esters of the polymerized rosins, and purified products, hydrides and disproportionates of the α, β-unsaturated carboxylic acid modified products And one or more of these can be used.

  The flux of each embodiment may further contain other resin such as acrylic resin in addition to rosin, and as other resin, acrylic resin, terpene resin, modified terpene resin, terpene phenol resin, modified terpene phenol resin, Furthermore, at least one resin selected from styrene resin, modified styrene resin, xylene resin, modified xylene resin, polyethylene, polypropylene, polyvinyl acetate, polyvinyl alcohol, polyethylene polypropylene copolymer, and polyethylene polyvinyl acetate copolymer Can be included. As a modified terpene resin, aromatic modified terpene resin, hydrogenated terpene resin, hydrogenated aromatic modified terpene resin etc. can be used. A hydrogenated terpene phenol resin etc. can be used as a modified terpene phenol resin. As the modified styrene resin, styrene acrylic resin, styrene maleic acid resin and the like can be used. As the modified xylene resin, a phenol modified xylene resin, an alkylphenol modified xylene resin, a phenol modified resol type xylene resin, a polyol modified xylene resin, a polyoxyethylene addition xylene resin, and the like can be used. The amount of the other resin is 15 wt% or less of the rosin, preferably 10 wt% or less of the rosin, more preferably 5 wt% or less of the rosin, when the total amount of the rosin is 100.

  As organic acids, glutaric acid, adipic acid, azelaic acid, eicosan diacid, citric acid, glycolic acid, succinic acid, salicylic acid, diglycolic acid, dipicolinic acid, dibutyl aniline diglycolic acid, suberic acid, sebacic acid, thioglycol Acid, phthalic acid, isophthalic acid, terephthalic acid, dodecanedioic acid, parahydroxyphenylacetic acid, picolinic acid, phenylsuccinic acid, fumaric acid, maleic acid, malonic acid, lauric acid, benzoic acid, tartaric acid, trisocyanate isocyanurate Carboxyethyl), glycine, 1,3-cyclohexanedicarboxylic acid, 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (hydroxymethyl) butanoic acid, 4-tert-butylbenzoic acid, 2,3- Dihydroxybenzoic acid, 2,4-diethyl glutaric acid, 2-Q Phosphoric acid, 3-hydroxybenzoic acid, malic acid, p- anisic acid, palmitic acid, stearic acid, 12-hydroxystearic acid, oleic acid, linoleic acid, and linolenic acid.

  Further, as organic acids, hydrogen was added to dimer acid which is a reaction product of oleic acid and linoleic acid, trimer acid which is a reaction product of oleic acid and linoleic acid, and dimer acid which is a reaction product of oleic acid and linoleic acid Either hydrogenated dimer acid or hydrogenated trimer acid obtained by adding hydrogen to trimer acid which is a reactant of oleic acid and linoleic acid, or dimer acid which is a reactant of oleic acid and linoleic acid, oleic acid and linoleic acid And a hydrogenated dimer acid obtained by adding hydrogen to a dimer acid obtained by reacting oleic acid and linoleic acid, and a hydrogenated trimer obtained by adding hydrogen to a trimer acid obtained by reacting oleic acid and linoleic acid An acid etc. are mentioned. Furthermore, hydrogen was added to the dimer acid other than the reactant of oleic acid and linoleic acid, the trimer acid other than the reactant of oleic acid and linoleic acid, and the dimer acid other than the reactant of oleic acid and linoleic acid as the organic acid Hydrogenated dimer acid or hydrogenated trimer acid obtained by adding hydrogen to trimer acid other than the reactant of oleic acid and linoleic acid Dimer acid which is a reactant of acrylic acid, trimer acid which is a reactant of acrylic acid, methacrylic acid The dimer acid which is a reactant of this, the trimer acid which is a reactant of methacrylic acid, the dimer acid which is a reactant of acrylic acid and methacrylic acid, the reactant of trimer acid which is a reactant of acrylic acid and methacrylic acid, and oleic acid Some dimer acids, trimer acid which is a reactant of oleic acid, dimer acid which is a reactant of linoleic acid, and tore which is a reactant of linoleic acid Meric acid, dimer acid which is a reactant of linolenic acid, trimer acid which is a reactant of linolenic acid, dimer acid which is a reactant of acrylic acid and oleic acid, trimer acid which is a reactant of acrylic acid and oleic acid, acrylic Dimer acid which is a reaction product of acid and linoleic acid, trimer acid which is a reaction product of acrylic acid and linoleic acid, dimer acid which is a reaction product of acrylic acid and linolenic acid, trimer acid which is a reaction product of acrylic acid and linolenic acid A dimer acid which is a reaction product of methacrylic acid and oleic acid, a trimer acid which is a reaction product of methacrylic acid and oleic acid, a dimer acid which is a reaction product of methacrylic acid and linoleic acid, a reaction product of methacrylic acid and linoleic acid Trimer acid, dimer acid which is a reaction product of methacrylic acid and linolenic acid, trimer which is a reaction product of methacrylic acid and linolenic acid The dimer acid which is a reaction product of oleic acid and linolenic acid, the trimer acid which is a reaction product of oleic acid and linolenic acid, the dimer acid which is a reaction product of linoleic acid and linolenic acid, the reaction product of linoleic acid and linolenic acid Trimer acid, hydrogenated dimer acid obtained by adding hydrogen to dimer acid other than the reaction product of oleic acid and linoleic acid, hydrogenated trimer acid obtained by adding hydrogen to trimer acid other than the reaction product of oleic acid and linoleic acid, etc. It can be mentioned.

  Examples of amines include monoethanolamine, diphenylguanidine, ethylamine, triethylamine, ethylenediamine, triethylenetetramine, 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4 -Methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2 Undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellite 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-ethyl-4'-methylimidazolyl- (1')]-ethyl-s- Triazine, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5- Dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo [1,2-a] benzimidazo 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2-phenylimidazoline, 2,4-diamino-6-vinyl-s-triazine, 2,4-diamino-6-vinyl -S-Triazine isocyanuric acid adduct, 2,4-diamino-6-methacryloyloxyethyl-s-triazine, epoxy-imidazole adduct, 2-methylbenzimidazole, 2-octylbenzimidazole, 2-pentylbenzimidazole, 2- (1-ethyl pentyl) benzimidazole, 2-nonyl benzimidazole, 2- (4-thiazolyl) benzimidazole, benzimidazole, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2 ') -Hydroxy-3'-tert- Butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-amylphenyl) benzotriazole, 2- (2'-hydroxy-5'-) tert-Octylphenyl) benzotriazole, 2,2'-methylenebis [6- (2H-benzotriazol-2-yl) -4-tert-octylphenol], 6- (2-benzotriazolyl) -4-tert- Octyl-6'-tert-butyl-4'-methyl-2,2'-methylenebisphenol, 1,2,3-benzotriazole, 1- [N, N-bis (2-ethylhexyl) aminomethyl] benzotriazole, Carboxybenzotriazole, 1- [N, N-bis (2-ethylhexyl) aminomethyl] methylbenzotria , 2,2 '-[[(methyl-1H-benzotriazol-1-yl) methyl] imino] bisethanol, 1- (1', 2'-dicarboxyethyl) benzotriazole, 1- (2,2, 3-dicarboxypropyl) benzotriazole, 1-[(2-ethylhexylamino) methyl] benzotriazole, 2,6-bis [(1H-benzotriazol-1-yl) methyl] -4-methylphenol, 5-methyl Benzotriazole, 5-phenyltetrazole and the like can be mentioned.

  The amine hydrohalide is a compound obtained by reacting an amine and a hydrogen halide, and includes aniline hydrochloride, aniline hydrobromide and the like. As the amine of the amine hydrohalide salt, the above-mentioned amine can be used, and ethylamine, ethylenediamine, triethylamine, methylimidazole, 2-ethyl-4-methylimidazole and the like can be mentioned, and as the hydrogen halide, chlorine, Examples thereof include bromine, iodine and hydrides of fluorine (hydrogen chloride, hydrogen bromide, hydrogen iodide, hydrogen fluoride). Moreover, it may replace with an amine hydrohalide salt, or it may combine with an amine hydrohalide salt, and a borofluoride may be included, and boro hydrofluoric acid etc. are mentioned as a borofluoride.

  Examples of the organic halogen compounds include trans-2,3-dibromo-1,4-butenediol which is an organic bromo compound, triallyl isocyanurate hexabromide, 1-bromo-2-butanol, 1-bromo-2-propanol, 3 -Bromo-1-propanol, 3-bromo-1,2-propanediol, 1,4-dibromo-2-butanol, 1,3-dibromo-2-propanol, 2,3-dibromo-1-propanol, 2, 3-dibromo-1,4-butanediol, 2,3-dibromo-2-butene-1,4-diol, trans-2,3-dibromo-2-butene-1,4-diol, cis-2,3 -Dibromo-2-butene-1,4-diol, tetrabromophthalic acid, bromosuccinic acid, 2,2,2-tribromoethanol and the like. In addition, chlorochloroalkanes which are organic chloro compounds, chlorinated fatty acid esters, hetic acid, hetic acid anhydride and the like can be mentioned. Further, fluorine-based surfactants which are organic fluoro compounds, surfactants having a perfluoroalkyl group, polytetrafluoroethylene and the like can be mentioned.

  As silicone, dimethyl silicone oil, cyclic silicone oil, methyl phenyl silicone oil, methyl hydrogen silicone oil, higher fatty acid modified silicone oil, alkyl modified silicone oil, alkyl / aralkyl modified silicone oil, amino modified silicone oil, epoxy modified silicone oil And polyether modified silicone oil, alkyl polyether modified silicone oil, carbinol modified silicone oil and the like.

  Examples of organophosphorus compounds include methyl acid phosphate, ethyl acid phosphate, isopropyl acid phosphate, monobutyl acid phosphate, butyl acid phosphate, dibutyl acid phosphate, butoxyethyl acid phosphate, 2-ethyl acid phosphate Fate, bis (2-ethylhexyl) phosphate, monoisodecyl acid phosphate, isodecyl acid phosphate, lauryl acid phosphate, isotridecyl acid phosphate, stearyl acid phosphate, oleyl acid phosphate, beef tallow phosphate, Coconut oil phosphate, isostearyl acid phosphate, alkyl acid phosphate, tetracosyl acid phosphate, ethylene glycol Lumpur acid phosphate, 2-hydroxyethyl methacrylate acid phosphate, dibutyl pyrophosphate acid phosphate, 2-ethylhexyl phosphonic acid mono-2-ethylhexyl, alkyl (alkyl) phosphonates, and the like.

  As an antifoamer, an acrylic polymer, vinyl ether polymer, butadiene polymer etc. are mentioned.

<Example of configuration of core wire solder of this embodiment>
The core solder of this embodiment may be a columnar shape such as a pellet, a disk, a ring, a tip, a ball, or a column called a column other than the linear solder filled with the flux described above. The flux used for the solder core is required to be solid at room temperature or to have a predetermined high viscosity so as not to flow out in the process of processing the solder. In addition, the viscosity calculated | required by the flux in the case of using with solder paste is 3500 Pa.s or more, for example. The wire diameter of the core solder is 0.1 mm or more and 1.6 mm or less, preferably 0.3 mm or more and 1.3 mm or less, and more preferably 0.6 mm or more and 1.0 mm or less. The content of the flux filled in the core solder is 0.5 wt% or more and 6 wt% or less, and preferably 1.5 wt% or more and 3 wt% or less, where 100 is core solder.

  The solder may be Sn alone, or Sn-Ag, Sn-Cu, Sn-Ag-Cu, Sn-Bi, Sn-In, Sn-Zn, Sn-Pb, or the like. The alloy is made of an alloy obtained by adding Sb, Bi, In, Cu, Zn, As, Ag, Cd, Fe, Ni, Co, Au, Ge, P, Pb, Zr and the like.

<Configuration Example of Flux-Coated Solder of this Embodiment>
The flux-coated solder of the present embodiment is a solder coated with the flux described above. The flux-coated solder may have a columnar shape such as a pellet, a disk, a ring, a tip, a ball, or a cylinder called a column, in addition to the linear solder. The flux coated with the solder is a solid that adheres to the surface of the solder at normal temperature.

  The solder may be Sn alone, or Sn-Ag, Sn-Cu, Sn-Ag-Cu, Sn-Bi, Sn-In, Sn-Zn, Sn-Pb, or the like. The alloy is made of an alloy obtained by adding Sb, Bi, In, Cu, Zn, As, Ag, Cd, Fe, Ni, Co, Au, Ge, P, Pb, Zr and the like.

<The effect example of the flux of this embodiment, core solder and flux coated solder>
The solid solvent or the phenolic solid solvent, or the flux containing the solid solvent and the phenolic solid solvent is in a form having a solid or a predetermined viscosity at normal temperature.

  In addition, when it does not contain a phenolic solid solvent, it contains an activator, and when it contains a phenolic solid solvent, it has sufficient activity for metal oxides without containing any activator, and solder In the process of heating to a temperature range exceeding the melting point of the above, the viscosity of the solid solvent and the phenolic solid solvent decreases and flows.

  Thereby, the flux of the present embodiment can be used for core solder and flux coated solder to obtain sufficient activity for removing metal oxides. Moreover, since it does not flow at normal temperature, it is suitable as a flux of core solder. Furthermore, solid solvents and phenolic solid solvents are suitable for low-residue applications because they have volatility with the heat history assumed for soldering.

<An example of the soldering method of this embodiment>
FIG. 1 is an explanatory view showing an example of a soldering iron used in the soldering method of the present embodiment, and FIGS. 2A, 2B, 2C and 2D are illustrations showing the soldering method of the present embodiment. FIG.

  The soldering method of the present embodiment is applied to through-hole mounting, a single-sided board, and the like. In the soldering iron 1A used in the soldering method of the present embodiment, the through holes 2 are formed along the central axis of the soldering iron 1A, and the heater 3 is provided as heating means for heating the soldering iron 1A.

In the soldering iron 1A, the diameter D of the through hole 2 is larger than the diameter d ₁ of the entering solder H, and the soldering H can be supplied to the tip 10 of the soldering iron 1A through the through hole 2 It is. Further, soldering iron 1A, the diameter D of the through-holes 2 is greater than the diameter _{d 2} of the lead terminals 101 of the electronic component 100, the tip portion 10 of the through hole 2 it is possible to insert the lead terminal 101.

  In the soldering method of the present embodiment, as shown in FIG. 2A, the lead terminals 101 of the electronic component 100 are inserted into the through holes 201 formed in the substrate 200. Further, the soldering iron 1A is heated by the heater 3 until it exceeds the melting point of the solder, and the soldering iron 1A is controlled so as to maintain a predetermined temperature exceeding the melting point of the solder. Next, as shown in FIG. 2B, the tip portion 10 of the soldering iron 1A is brought into contact with or in proximity to the through hole 201 into which the lead terminal 101 is inserted, and the lead terminal 101 is inserted into the through hole 2 of the soldering iron 1A. Do.

  Next, the solder H cut into a predetermined length is supplied to the through hole 2 of the soldering iron 1A, and the solder H is brought into contact with the lead terminal 101 inserted in the through hole 2.

  By controlling the soldering iron 1A to maintain a predetermined temperature exceeding the melting point of the solder, as shown in FIG. 2C, the core solder is heated and the solder melts, and the through hole 201 and the lead terminal 101 is heated.

  When heating the solder H with the soldering iron 1A to a temperature exceeding the melting point of the solder, the viscosity of the flux in the solder decreases, and the flux flows to the through holes 201 and the lead terminals 101. The metal oxide on the surface of the through hole 201 and the lead terminal 101 is removed, and the molten solder wets and spreads.

  Next, as shown in FIG. 2D, by separating the soldering iron 1A from the through hole 201, the solder wetted to the through hole 201 and the lead terminal 101 is hardened.

  In the above-described soldering method, when the flux used in the core solder H is the flux of the present embodiment, the flux contains a solid solvent or a phenolic solid solvent, or a solid solvent and a phenolic solid solvent. Thus, the flux can be made solid or have a predetermined high viscosity. This is suitable as a flux of core solder.

  Moreover, solid solvents and phenolic solid solvents have volatility with the heat history assumed for soldering. On the other hand, even when the resin does not contain rosin or contains rosin, the amount of rosin can be made 30 wt% or less, the flux can be made solid or predetermined high viscosity, and the content of rosin can be reduced.

  As a result, the amount of flux that has been supplied to the through holes 2 of the soldering iron 1A and becomes a residue after heating is suppressed. For this reason, even if soldering iron H is supplied to the through hole 2 and soldering is performed continuously while the soldering iron 1A is controlled to maintain a predetermined temperature exceeding the melting point of the solder, Accumulation of residual carbides in the through holes 2 is suppressed, and the occurrence of defects such as clogging of the through holes 2 of the soldering iron with residual carbides can be suppressed.

  The fluxes of Examples and Comparative Examples were prepared with the compositions shown in Tables 1 and 2 below, and the residual amount and processability were verified. The composition ratio in Tables 1 and 2 is wt (wt)% when the total amount of flux is 100.

<Evaluation of residual amount>
(1) Verification method As a test evaluation method by the TG method (thermogravimetry), 10 mg of the flux of each Example and each Comparative Example is packed in an aluminum pan, and 25 ° C. under N ₂ atmosphere using TGD 9600 manufactured by ULVAC. It heated by -10 degreeC / min of temperature rising rates to -350 degreeC. It was determined whether the weight of each flux after heating was less than 15% before heating.

(2) Judgment criteria :: The weight was 15% or less before heating x: The weight was larger than 15% before heating

  It can be said that, in the flux whose weight after heating became 15% or less before heating, the components in the flux were sufficiently volatilized by heating. It can be said that the flux whose weight was greater than 15% before heating had insufficient volatilization of the components in the flux. When flux with insufficient volatilization is used for core solder and applied to the above-mentioned soldering method, a large amount of residual carbide deposits on the through hole of the soldering iron, and core solder can not be supplied properly. Cause problems such as

<Evaluation of processability>
(1) Verification method The flux of the example and the comparative example was used as a sample, and the state at 25 ° C. was observed to determine whether it was solid or liquid. When the flux was liquid, the viscosity of the flux was measured by rotating the plate at 6 Hz after sandwiching the flux between the plates of a rheometer (Thermo Scientific HAAKE MARS IIITM). And the workability at the time of manufacturing a core solder was evaluated by the criteria shown below.

(2) Judgment standard O: The state at 25 ° C. was solid. Or although the state in 25 degreeC is a liquid, the viscosity measured by the rheometer was more than 3500 Pa.s. While the state of the flux at 25 ° C. was solid or the state at 25 ° C. was liquid, it was possible to make a core solder when the viscosity measured by the rheometer is 3500 Pa · s or more.
X: The state at 25 ° C. was liquid, and the viscosity measured by the rheometer was less than 3500 Pa · s. When the state of the flux at 25 ° C. was liquid and the viscosity measured by the rheometer was less than 3500 Pa · s, the flux flowed, and it was not possible to make a core solder.

<Overall evaluation>
:: The amount of residue and the evaluation of processability were both ×: the amount of residue and the evaluation of processability were all or all x

  In Example 1 containing 95 wt% of neopentyl glycol as a solid solvent within the range specified in the present invention and 5 wt% of adipic acid as the organic acid within the range specified in the present invention, the state at 25 ° C. is solid Alternatively, even when the state at 25 ° C. is liquid, the viscosity is 3500 Pa · s or more, and a sufficient effect on the processability at the time of producing the core solder is obtained. In addition, when the amount of residue is 15 wt% or less, a sufficient effect of suppressing the amount of residue to make a low residue is obtained.

  The present invention comprises 70 wt% reduced neopentyl glycol as a solid solvent within the range specified in the present invention, 5 wt% adipic acid as an organic acid, 25 wt% eicosane diacid, and a combination of two or more organic acids according to the present invention Even in Example 2 which is within the range defined in, sufficient effects on the processability were obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  Within the range specified in the present invention, neopentyl glycol as a solid solvent is increased to 99.5 wt%, and N, N-diethylaniline hydrobromide as the amine hydrohalide salt is defined in the present invention Even in Example 3 containing 0.5 wt% of the inside, a sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  Even in Example 4 containing 95 wt% of dioxane glycol as a solid solvent within the range specified in the present invention and containing 5 wt% of adipic acid as the organic acid within the range specified in the present invention, sufficient effect on processability was gotten. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  Within the range specified in the present invention, 95 wt% of 4- (1,1,3,3-tetramethylbutyl) phenol is contained as the phenolic solid solvent, and within the range specified in the present invention, adipic acid as the organic acid Even in Example 5 containing 5 wt%, a sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  Even in Example 6 containing 95 wt% of catechol as the phenolic solid solvent within the range specified in the present invention and 5 wt% of the adipic acid as the organic acid within the range specified in the present invention, sufficient for processability The effect was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  Even in Example 7 which contains 100 wt% of 4- (1,1,3,3-tetramethylbutyl) phenol as a phenolic solid solvent within the range specified in the present invention and does not contain any other activator such as an organic acid. And sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  Even in Example 8 containing 100 wt% of catechol as a phenolic solid solvent within the range specified in the present invention and no other activator such as an organic acid, a sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  70 wt% of neopentyl glycol as a solid solvent within the range specified in the present invention, and 4- (1,1,3,3-tetramethylbutyl) phenol as a phenolic solid solvent within the range specified in the present invention Even in Example 9 containing 30 wt% of Hg and containing no other activator such as an organic acid, a sufficient effect on processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  Even in Example 10, which contains 95 wt% of neopentyl glycol as a solid solvent within the range specified in the present invention and 5 wt% of pimelic acid as the organic acid within the range specified in the present invention, sufficient for processability. The effect was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  Even in Example 11 containing 95 wt% of neopentyl glycol as a solid solvent within the range specified in the present invention and 5 wt% of suberic acid as the organic acid within the range specified in the present invention is sufficient for processability. The effect was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  Even Example 12 containing 95 wt% of neopentyl glycol as a solid solvent within the range specified in the present invention and 5 wt% of dodecanedioic acid as the organic acid within the range specified in the present invention is sufficient for processability. Effect was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  Within the range specified in the present invention, 95 wt% of 4- (1,1,3,3-tetramethylbutyl) phenol is contained as the phenolic solid solvent, and within the range specified in the present invention, 2-phenylimidazole as the amine Also in Example 13 containing 5 wt% of Sb, a sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  In the range specified in the present invention, 96 wt% of neopentyl glycol as a solid solvent, and 4 wt% of N, N-diethylaniline hydrobromide as an amine hydrohalide salt in the range specified in the present invention Also in Example 14 containing, sufficient effects on the processability were obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  90 wt% of 4- (1,1,3,3-tetramethylbutyl) phenol as a phenolic solid solvent within the range specified in the present invention, and 2,2,2-tribromoethanol as an organic halogen compound Even in Example 15 containing 10 wt% within the range defined by the invention, a sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  99% by weight of 4- (1,1,3,3-tetramethylbutyl) phenol as a phenolic solid solvent within the range specified in the present invention, and trans-2,3-dibromo-2-butene as an organic halogen compound The sufficient effect on the processability was obtained also in Example 16 in which 1 wt% of 1,4-diol was contained in the range specified in the present invention. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  99% by weight of 4- (1,1,3,3-tetramethylbutyl) phenol as a phenolic solid solvent within the range specified in the present invention, and triallyl isocyanurate hexabromide as an organic halogen compound is specified in the present invention Even in Example 17 containing 1 wt% within the range, a sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  90 wt% of neopentyl glycol as solid solvent within the range defined in the present invention, 5 wt% of adipic acid as organic acid within the range defined in the present invention, dimethyl silicone oil as silicone is defined in the present invention Also in Example 18 containing 5 wt% of the metal oxide, a sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  85 wt% of neopentyl glycol as solid solvent in the range specified in the present invention, 5 wt% of adipic acid as organic acid in the range specified in the present invention, and isodecyl acid phosphate as organic phosphorus compound Even in Example 19 containing 10 wt% within the range defined by the invention, sufficient effects on the processability were obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  92 wt% of neopentyl glycol as solid solvent in the range specified in the present invention, 5 wt% of adipic acid in the range specified in the present invention as organic acid, acrylic polymer as the antifoam agent in the present invention Even in Example 20 containing 3 wt% within the above range, a sufficient effect on processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  90% by weight of neopentyl glycol as solid solvent within the range specified in the present invention, 5% by weight of hydrogenated rosin as the rosin derivative within the range specified by the present invention, eicosanninic acid as the organic acid according to the present invention Even in Example 21 containing 5 wt% of the above range, a sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  Containing 85 wt% neopentyl glycol as a solid solvent within the range specified in the present invention, containing 10 wt% hydrogenated rosin as the rosin derivative within the range specified in the present invention, and defining eicosanninic acid as an organic acid in the present invention Even in Example 22 containing 5 wt% of the above range, a sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  70 wt% of 4- (1,1,3,3-tetramethylbutyl) phenol as a phenolic solid solvent within the range specified in the present invention, and within the range specified in the present invention as hydrogenated rosin as a rosin derivative Also in Example 23 containing 30 wt% of, sufficient effect on processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  90 wt% of 4- (1,1,3,3-tetramethylbutyl) phenol as a phenolic solid solvent within the range specified in the present invention, and 5 wt% of a natural rosin within the range specified in the present invention Also in Example 24 containing 5 wt% of eicosanninic acid as an organic acid within the range specified in the present invention, a sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  90 wt% of 4- (1,1,3,3-tetramethylbutyl) phenol as a phenolic solid solvent within the range specified in the present invention, and polymerized rosin as the rosin derivative within the range specified in the present invention Even in Example 25 containing 5 wt% and containing 5 wt% of eicosanninic acid as an organic acid within the range specified in the present invention, a sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  90 wt% of 4- (1,1,3,3-tetramethylbutyl) phenol as a phenolic solid solvent within the range defined in the present invention, and a range defined in the present invention as disproportionated rosin as a rosin derivative Even in Example 26 which contains 5 wt% of Eikosan and 5 wt% of eicosanninic acid as an organic acid within the range specified in the present invention, a sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  90% by weight of 4- (1,1,3,3-tetramethylbutyl) phenol as a phenolic solid solvent within the range specified in the present invention, hydrogenated disproportionated rosin as the rosin derivative is specified in the present invention Also in Example 27 which contains 5 wt% of eicosanninic acid as an organic acid within the range specified in the present invention, a sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  90 wt% of 4- (1,1,3,3-tetramethylbutyl) phenol as a phenolic solid solvent within the range defined in the present invention, and an acrylic acid-modified rosin as the rosin derivative in the range defined in the present invention Even in Example 28 which contains 5 wt% of Eikosan and 5 wt% of eicosanninic acid as an organic acid within the range specified in the present invention, a sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  90% by weight of 4- (1,1,3,3-tetramethylbutyl) phenol as a phenolic solid solvent within the range specified in the present invention, acrylic acid modified hydrogenated rosin as the rosin derivative is specified in the present invention Also in Example 29 containing 5 wt% of eicosanninic acid as an organic acid within the range specified in the present invention, a sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  90 wt% of 4- (1,1,3,3-tetramethylbutyl) phenol as a phenolic solid solvent within the range specified in the present invention, and a rosin ester as the rosin derivative within the range specified in the present invention Even in Example 30 which contains 5 wt% and contains 5 wt% of eicosanninic acid as an organic acid within the range specified in the present invention, a sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  In the range specified in the present invention, 75 wt% of 4- (1,1,3,3-tetramethylbutyl) phenol is contained as a phenolic solid solvent, 5 wt% of natural rosin, 5 wt% of polymerized rosin as a rosin derivative, 5 wt% disproportionated rosin and 5 wt% acrylic acid modified rosin, and a combination of two or more rosins is within the range defined in the present invention, and within the range defined in the present invention, eicosanninic acid as the organic acid Even in Example 31 containing 5 wt% of Sb, a sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  Within the range specified in the present invention, 75 wt% of 4- (1,1,3,3-tetramethylbutyl) phenol is contained as a phenolic solid solvent, and 5 wt% of hydrogenated rosin as a rosin derivative, hydrogenated heterogeneous addition 5 wt% of rosin, 5 wt% of acrylic acid-modified hydrogenated rosin, 5 wt% of rosin ester, and a combination of two or more rosins is within the range specified in the present invention, and eicosanninic acid as an organic acid in the present invention Even in Example 32 containing 5 wt% of the specified range, a sufficient effect on the processability was obtained. Moreover, the sufficient effect of suppressing the amount of residues and making it a low residue was acquired.

  On the other hand, it contains 50 wt% of neopentyl glycol as a solid solvent below the range specified in the present invention, 45 wt% of an acrylic acid-modified rosin as the rosin derivative exceeds the range specified in the present invention, as an organic acid In Comparative Example 1 containing 5 wt% of eicosanninic acid within the range defined in the present invention, the effect of reducing the residue was obtained, but the state at 25 ° C. is a liquid and the viscosity is less than 3500 Pa · s, Sufficient effect was not obtained on the processability at the time of producing the inlay solder.

  It contains 50% by weight of 4- (1,1,3,3-tetramethylbutyl) phenol as a solid phenolic solvent below the range specified in the present invention, and a polymerized rosin as the rosin derivative exceeds the range specified in the present invention In Comparative Example 2 containing 45 wt% and containing 5 wt% of eicosanninic acid as an organic acid in the range defined in the present invention, the amount of residue exceeds 15 wt%, the amount of residue can not be suppressed, and the effect of making low residue is obtained. It was not. In addition, sufficient effect on the processability was not obtained.

  In Comparative Example 3 containing 40 wt% of hexyl diglycol as a solvent, 50 wt% of natural rosin as a solvent, and 10 wt% of eicosanninic acid as an organic acid, the effect of obtaining a low residue is obtained. However, sufficient effect on the processability was not obtained.

  From the above, a flux containing 70 wt% to 99.5 wt% of solid solvent and 0.5 wt% to 30 wt% of activator, 70 wt% to 100 wt% of phenolic solid solvent, 0 wt% or more of activator Flux containing 30 wt% or less, 70 wt% to 99.5 wt% of solid solvent, more than 0 wt% to 30 wt% of phenolic solid solvent, 0 wt% to 30 wt% of activator, or any of these fluxes In the used core solder and flux coat solder, the effect of suppressing the amount of residue was obtained. Moreover, the effect that processability becomes favorable was acquired.

  These effects were not inhibited by the inclusion of rosins and additives within the range defined in the present invention.

Claims (9)

Using a core solder made of flux-filled solder, the core solder is heated with a soldering iron to a temperature exceeding the melting point of the solder to heat the object to be joined, and A soldering method for melting the contained solder,
The solder iron is supplied to the through hole formed along the central axis and the solder is supplied, the solder iron maintains a temperature exceeding the melting point of the solder, and the solder iron is supplied to the through hole. 70 wt% or more and 99.5 wt% or less of solid solvent used for the soldering method of heating the core solder
A flux for a core solder , characterized by containing 0.5 wt% or more and 30 wt% or less of an activator. Using a core solder made of flux-filled solder, the core solder is heated with a soldering iron to a temperature exceeding the melting point of the solder to heat the object to be joined, and A soldering method for melting the contained solder,
The solder iron is supplied to the through hole formed along the central axis and the solder is supplied, the solder iron maintains a temperature exceeding the melting point of the solder, and the solder iron is supplied to the through hole. 70 wt% or more and 100 wt% or less of phenolic solid solvent used in the soldering method of heating the core solder
A flux for a core solder, comprising 0 wt% or more and 30 wt% or less of an activator. Using a core solder made of flux-filled solder, the core solder is heated with a soldering iron to a temperature exceeding the melting point of the solder to heat the object to be joined, and A soldering method for melting the contained solder,
The solder iron is supplied to the through hole formed along the central axis and the solder is supplied, the solder iron maintains a temperature exceeding the melting point of the solder, and the solder iron is supplied to the through hole. 0% by weight or more and 30% by weight or less of phenolic solid solvent used for the soldering method of heating the core solder
70 wt% to 99.5 wt% of solid solvent other than phenolic solid solvent,
A flux for a core solder, comprising 0 wt% or more and 30 wt% or less of an activator. The flux for the core solder according to any one of claims 1 to 3, which is solid at 25 ° C or liquid having a viscosity of 3500 Pa · s or more. The activator is any of an organic acid, an amine, an organic halogen compound, an amine hydrohalide, or a combination of two or more of an organic acid, an amine, an organic halogen compound, and an amine hydrohalide. The flux for the core solder according to any one of claims 1 to 4, characterized in that A flux for the core solder according to any one of claims 1 to 5 filled in the solder. A core solder as set forth in any one of claims 1 to 5. The core solder is made of solder filled with flux containing 70 wt% to 99.5 wt% of solid solvent and 0.5 wt% to 30 wt% of activator, and the temperature is higher than the melting point of the solder. In the soldering method of heating the solder to heat the joint object and heating the bonding object and melting the solder in the above-mentioned manner,
The solder iron is supplied to the through hole formed along the central axis and the solder is supplied, the solder iron maintains a temperature exceeding the melting point of the solder, and the solder iron is supplied to the through hole. Heat the solder
A soldering method characterized by A core solder made of solder filled with a flux containing 70 wt% to 100 wt% of a phenolic solid solvent and 0 wt% to 30 wt% of an activator, is used until the temperature exceeds the melting point of the solder In the soldering method, the core solder is heated with a soldering iron to heat the object to be joined and the core solder is melted,
The solder iron is supplied to the through hole formed along the central axis and the solder is supplied, the solder iron maintains a temperature exceeding the melting point of the solder, and the solder iron is supplied to the through hole. Heat the solder
A soldering method characterized by A solder filled with flux containing more than 0 wt% to 30 wt% of a phenolic solid solvent, 70 wt% to 99.5 wt% of a solid solvent other than a phenolic solid solvent, and 0 wt% to 30 wt% of an activator. In the soldering method, the core solder is heated with a soldering iron to a temperature exceeding the melting point of the solder by using the core solder, and the bonding target is heated and the core solder is melted. ,
The solder iron is supplied to the through hole formed along the central axis and the solder is supplied, the solder iron maintains a temperature exceeding the melting point of the solder, and the solder iron is supplied to the through hole. Heat the solder
A soldering method characterized by

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