JP6575702B1 - Flux and solder paste - Google Patents

Abstract

The present invention provides a flux and a solder paste using a flux that imparts thixotropy and is excellent in printability, printing sag suppression ability, and heating sag suppression ability. A flux includes a thixotropic agent, an acid-modified rosin, and a solvent. The thixotropic agent includes a cyclic amide compound obtained by cyclic polycondensation of dicarboxylic acid and / or tricarboxylic acid and diamine and / or triamine, and monocarboxylic acid. It consists of an acyclic amide compound in which an acid, a dicarboxylic acid and / or a tricarboxylic acid are acyclic polycondensed. In the cyclic amide compound, the carbon number of the dicarboxylic acid and the tricarboxylic acid is 3 to 10 and the carbon number of the diamine and the triamine is 2 to 54, and the cyclic amide compound is 0.1 wt% to 8.0 wt%, acyclic The amide compound is contained in an amount of 0.5 wt% or more and 8.0 wt% or less, and the total amount of the cyclic amide compound and the non-cyclic amide compound is 1.5 wt% or more and 10.0 wt% or less. [Selection figure] None

Description

  The present invention relates to a flux used for soldering and a solder paste using the flux.

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

  In such a soldering flux and a solder paste containing metal powder, thixotropy is imparted by a thixotropic agent contained in the flux. The thixotropic agent builds a network in the flux and imparts thixotropic properties. When the flux has a thixotropy, when the shearing force is applied, the viscosity is lowered, so that workability such as printability is improved. In addition, by including a thixotropic agent, the sag of the solder paste after printing called printing sag and the sag of the solder paste when melted by heating called heating sag are retained by the network formed by the thixotropic agent. Sag is suppressed.

  As the thixotropic agent, an amide-based thixotropic agent comprising an amide compound obtained by dehydration condensation of a fatty acid and an amine is used from the viewpoint of imparting thixotropy, improving printability, suppressing printing sagging, and heating sagging (for example, Patent Documents). 1). As the thixotropic agent, an ester-based thixotropic agent made of castor oil is used.

Japanese Patent No. 3350767

  Amide-based thixotropic agents easily form hydrogen bonds within and between molecules due to amide bonds, and when they become polymers, they have poor compatibility and are difficult to disperse uniformly, thereby making printability unstable. Further, when the amount of the polymer amide compound is increased, the viscosity becomes extremely high, so that the printability is deteriorated. Furthermore, even with ester thixotropic agents, heating sag cannot be sufficiently suppressed. In addition, the finish after mounting, for example, the wetting speed may be completely different depending on the difference in thermal history during soldering. Therefore, there is a demand for a flux that enables stable soldering with a good finish regardless of the thermal history.

  The present invention has been made in order to solve such problems, and provides a thixotropy and has excellent printability, ability to suppress printing sag, ability to suppress heat sag, and excellent solder wetting speed. It aims at providing the solder paste using.

  A thixotropic agent composed of a cyclic amide compound and an acyclic amide compound and a flux containing an acid-modified rosin improves thixotropy. A solder paste containing this flux and metal powder improves printability, and It was found that heating sag can be suppressed. Moreover, when soldering was performed using this flux, it discovered that the wetting speed of the solder improved.

Therefore, the present invention includes an acid-modified rosin, a thixotropic agent, and a solvent, and includes an acid-modified rosin of 5.0 wt% to 50.0 wt% and a rosin other than the acid-modified rosin of 0 wt% to 50 wt%. The total content of the acid-modified rosin and the other rosin is 35 wt% or more and 60 wt% or less, and the thixotropic agent is composed of a cyclic amide compound and an acyclic amide compound. %, A non-cyclic amide compound is contained in an amount of 0.5 wt% or more and 8.0 wt% or less, and the total of the cyclic amide compound and the non-cyclic amide compound is 1.5 wt% or more and 10.0 wt% or less. Is an amide compound having a molecular weight of 3000 or less obtained by cyclic polycondensation of dicarboxylic acid and / or tricarboxylic acid and diamine and / or triamine. Bromide compound is a flux is amide compound monocarboxylic acids, dicarboxylic acids and / or tricarboxylic acids, monoamines, diamines and / or triamines fused to acyclic.

  The cyclic amide compound preferably has 3 to 10 carbon atoms in the dicarboxylic acid and the tricarboxylic acid, and the cyclic amide compound has more preferably 6 to 10 carbon atoms in the dicarboxylic acid and the tricarboxylic acid.

  The cyclic amide compound preferably has 2 or more and 54 or less carbon atoms in the diamine and triamine, and the cyclic amide compound more preferably has 6 carbon atoms in the diamine and triamine.

  Further, the cyclic amide compound is preferably an amide compound obtained by cyclic polycondensation of a dicarboxylic acid having 3 to 10 carbon atoms and a diamine having 2 to 54 carbon atoms, and the cyclic amide compound has a carbon number. It is more preferably an amide compound obtained by cyclic polycondensation of 6 or more and 10 or less dicarboxylic acid and a diamine having 6 carbon atoms.

  The cyclic amide compound has a carbon number of dicarboxylic acid and tricarboxylic acid of 3 or more and 10 or less, and the diamine and triamine have a carbon number of 2 or more and 54 or less, and the acyclic amide compound is a monocarboxylic acid, dicarboxylic acid or tricarboxylic acid. It is preferable that carbon number of 2 or more and 28 or less, and monoamine, diamine and triamine have 0 or more and 54 or less carbon atoms.

  Moreover, it is preferable that a thixotropic agent contains an ester compound further, and it is more preferable that a thixotropic agent contains a castor hydrogenated oil as an ester compound.

  Further, the thixotropic agent preferably contains a cyclic amide compound in an amount of 0.5 wt% to 1.5 wt% and an acyclic amide compound in an amount of 0.5 wt% to 4.0 wt%, and the thixotropic agent contains an ester compound in an amount of 0 wt%. It is preferable to contain 8.0 wt% or less.

  Furthermore, the organic acid is 0 wt% or more and 10 wt% or less, the amine is 0 wt% or more and 20 wt%, the organic halogen compound is 0 wt% or more and 5 wt% or less, the amine hydrohalide is 0 wt% or more and 2 wt% or less, and the antioxidant is 0 wt%. % To 5 wt% or less is preferable.

  Moreover, this invention is the solder paste containing the flux mentioned above and metal powder.

  In the thixotropic agent consisting of a cyclic amide compound and a non-cyclic amide compound, the non-cyclic amide compound is cross-linked with a low-molecular cyclic amide compound. And thixotropy can be improved without increasing content of an acyclic amide compound, and precipitation of a thixotropic agent can be suppressed. The acid-modified rosin has heat resistance in the temperature range assumed for soldering and functions as an activator during soldering.

  With the solder paste using this flux, it is possible to obtain good printability in which bleeding, blurring and the like are suppressed, and it is possible to suppress printing sag through which the solder paste after printing flows. Furthermore, the heating sag of the solder paste due to heating during soldering can be suppressed. In addition, a good wetting rate is exhibited even under conditions with a large heat load, and a desired wetting rate is obtained.

It is a schematic diagram which shows the outline | summary of the molecular structure of dicarboxylic acid. It is a schematic diagram which shows the outline | summary of the molecular structure of diamine. It is a schematic diagram which shows the outline | summary of the molecular structure of an acyclic amide compound. It is a schematic diagram which shows the outline | summary of the molecular structure of an acyclic amide compound. It is a schematic diagram which shows the outline | summary of the molecular structure of a cyclic amide compound. It is a schematic diagram which shows the outline | summary of the molecular structure which bridge | crosslinked the acyclic amide compound with the cyclic amide compound.

<Example of flux of this embodiment>
The flux of the present embodiment includes a thixotropic agent, an acid-modified rosin, and a solvent. The thixotropic agent is composed of a cyclic amide compound and an acyclic amide compound.

  The cyclic amide compound is a low molecular amide compound having a molecular weight of 3000 or less, particularly a molecular weight of 1000 or less, obtained by cyclic polycondensation of dicarboxylic acid and / or tricarboxylic acid and diamine and / or triamine. Further, the acyclic amide compound is a non-cyclic amide oligomer having a molecular weight of 3000 or less, which is a non-cyclic polycondensation of monocarboxylic acid, dicarboxylic acid and / or tricarboxylic acid and monoamine, diamine and / or triamine, or a molecular weight of more than 3000. This is an acyclic high molecular amide polymer.

  FIG. 1 is a schematic diagram showing an outline of the molecular structure of a dicarboxylic acid, FIG. 2 is a schematic diagram showing an outline of the molecular structure of a diamine, and FIG. 3 is a schematic diagram showing an outline of the molecular structure of an acyclic amide compound. . As shown in FIG. 3, an acyclic amide compound is synthesized by polycondensation (dehydration condensation) of the dicarboxylic acid shown in FIG. 1 and the diamine shown in FIG.

The thixotropic agent composed of the acyclic amide compound shown in FIG. 3 is an amide group in which the carboxyl group (COOH) of the dicarboxylic acid shown in FIG. 1 and the amino group (NH ₂ ) of the diamine shown in FIG. A network is formed by hydrogen bonding between hydrogen (H) and oxygen (O) in C (═O) —NH within and between molecules. The amide bond site is indicated by (A), and the hydrogen bond site is indicated by (B).

  FIG. 4 is a schematic diagram showing an outline of the molecular structure of an acyclic amide compound. When the acyclic amide compound is polymerized, as shown in FIG. 4, hydrogen bonding (B) proceeds in the molecule, so that the solubility (compatibility) becomes very poor in the flux and coarse in the flux. May occur, resulting in poor thixotropy. In addition, a solder paste in which such a flux and metal powder are mixed has poor printability, and printing sagging and heating sagging occur.

  Therefore, by using a cyclic amide compound in combination with an acyclic amide compound, the cyclic amide compound crosslinks the acyclic amide compound with a non-covalent interaction, and constructs a relatively uniform thixotropic agent component network. Inhibits excessive thixotropic agent precipitation.

  FIG. 5 is a schematic diagram showing an outline of the molecular structure of a cyclic amide compound. Now, by dicondensing the dicarboxylic acid shown in FIG. 1 and the diamine shown in FIG. 2, a cyclic amide compound is synthesized as a low molecular amide as shown in FIG.

  Since the cyclic amide compound has higher symmetry than the non-cyclic amide compound, it has a property of being easily crystallized as compared with the non-cyclic low-molecular amide. On the other hand, acyclic low molecular weight amides have polar end groups, so that they are easily compatible with the flux and difficult to crystallize, so that it is difficult to impart thixotropy due to network formation. On the other hand, since the cyclic amide compound does not have a polar end group, the cyclic amide compound is hardly compatible with the flux and easily imparts thixotropy due to network formation.

  As a result, in the thixotropic agent consisting of a cyclic amide compound and an acyclic amide compound, hydrogen bonding between the cyclic amide compound and the acyclic amide compound is promoted, and the hydrogen bond in the molecule of the acyclic amide compound is inhibited. It is thought that it is done.

  FIG. 6 is a schematic diagram showing an outline of a molecular structure in which a non-cyclic amide compound is crosslinked with a cyclic amide compound. In the thixotropic agent comprising a cyclic amide compound and an acyclic amide compound, as shown in FIG. 6, the cyclic amide compound and the acyclic amide compound are hydrogen bonded (B), so that the cyclic amide compound is non-cyclic amide compound. It is believed that a network of relatively uniform components crosslinked by covalent interactions is constructed.

  Therefore, in a flux containing a thixotropic agent composed of a cyclic amide compound and an acyclic amide compound, excessive precipitation of the thixotropic agent is suppressed and thixotropic properties are excellent as compared with a thixotropic agent composed of an acyclic amide compound. Further, a solder paste made of a metal powder and a flux containing a thixotropic agent composed of a cyclic amide compound and an acyclic amide compound is excellent in printability, suppresses printing sag, and further suppresses heat sag.

  The cyclic amide compound and the non-cyclic amide compound are represented as [n + n] type, where n is the number of carboxylic acids and n is the number of amines. The cyclic amide compound is constructed from [1 + 1] type to [n + n] type, preferably [1 + 1] type to [3 + 3] type, particularly preferably [2 + 2] type. FIG. 5 shows an example of the [2 + 2] type in which dicarboxylic acid and diamine are cyclically condensed, and the cyclic amide compound is preferably [2 + 2] type in which dicarboxylic acid and diamine are cyclically condensed.

  The cyclic amide compound is a [2 + 2] type in which tricarboxylic acid and diamine are polycondensed cyclically, and one of the functional groups of tricarboxylic acid is in an unbonded state with other compounds. Examples include [2 + 3] type in which a cyclic polycondensation forms a cage structure, and [3 + 2] type in which a dicarboxylic acid and triamine are polycondensed into a cage structure to form a cage structure.

  Thus, the cyclic amide compound includes an amide oligomer obtained by cyclic polycondensation of dicarboxylic acid and diamine, an amide oligomer obtained by cyclic polycondensation of tricarboxylic acid and diamine, an amide oligomer obtained by cyclic polycondensation of dicarboxylic acid and triamine, and tricarboxylic acid. Amide oligomer obtained by cyclic polycondensation of triamine, amide oligomer obtained by cyclic polycondensation of dicarboxylic acid and tricarboxylic acid and diamine, amide oligomer obtained by cyclic polycondensation of dicarboxylic acid and tricarboxylic acid and triamine, dicarboxylic acid, diamine and triamine are cyclic Any of amide oligomers polycondensed to amides, amide oligomers obtained by cyclic polycondensation of tricarboxylic acid with diamine and triamine, and amide oligomers obtained by cyclic polycondensation of dicarboxylic acid and tricarboxylic acid with diamine and triamine It may be.

  Further, the acyclic amide compound is an amide compound in which a monocarboxylic acid and a diamine and / or triamine are acyclic polycondensed, and a dicarboxylic acid and / or a tricarboxylic acid and a monoamine are acyclic polycondensed. In some cases, when the amide compound contains a monocarboxylic acid or a monoamine, the monocarboxylic acid and the monoamine function as terminal molecules, resulting in an acyclic amide oligomer having a reduced molecular weight. The acyclic amide compound becomes an acyclic polymer amide polymer when it is an amide compound part in which dicarboxylic acid and / or tricarboxylic acid and diamine and / or triamine are non-cyclically polycondensed. Furthermore, the acyclic amide compound includes an amide compound obtained by polycondensing a monocarboxylic acid and a monoamine in an acyclic manner.

  The reason why an amide compound in which a monocarboxylic acid and a monoamine are condensed non-cyclically can form a network will be described below.

  The molecular structure of the monocarboxylic acid is shown in the following chemical formula (1), the molecular structure of the monoamine is shown in the chemical formula (2) below, and the molecular structure of the acyclic amide compound in which the monocarboxylic acid and the monoamine are condensed is shown below. It is shown in the formula (3).

When the carboxyl group (COOH) of the monocarboxylic acid represented by the chemical formula (1) and the amino group (NH ₂ ) of the monoamine represented by the chemical formula ( ₂ ) are amide-bonded by condensation, the non-functionality represented by the chemical formula (3) A cyclic amide compound is formed. In addition, the hydrogen (H) and oxygen (O) of the amide group C (═O) —NH of the acyclic amide compound are connected by hydrogen bonding between molecules. The amide bond site in the molecule of the acyclic amide compound is indicated by (A), and the hydrogen bond site between the molecules of the acyclic amide compound is indicated by (B).

  Thus, monoamides (monoamides) having one amide group in the molecule are connected by hydrogen bonds. This aggregate of monoamides by hydrogen bonding is treated as a supramolecule. A supramolecule refers to a collection of molecules constructed from non-covalent interactions such as hydrogen bonds and hydrophobic interactions. Hydrogen bonds show strong interactions and become a stable structure.

  Acyclic amide compounds, which are monoamides condensed with monocarboxylic acids and monoamines, are linked by hydrogen bond interactions derived from amide bonds, and in addition, molecular chains connected by hydrogen bond interactions, especially main chain amides. A cross-linked site is formed by a hydrogen bond derived from a bond or an interaction between molecular chains by a hydrophobic interaction by a side chain, and grows into a three-dimensional network.

  As described above, an acyclic amide compound obtained by condensing a monocarboxylic acid and a monoamine has only one amide group, but can form a network by bonding by noncovalent interaction by hydrogen bonding.

  Thereby, the acyclic amide compound may include an amide compound in which a monocarboxylic acid and a monoamine are polycyclicly condensed.

  The cyclic amide compound contained as a thixotropic agent is an amide compound obtained by cyclic polycondensation of dicarboxylic acid and / or tricarboxylic acid and diamine and / or triamine, and has two or more amide groups.

  Thereby, when a cyclic amide compound is added to the thixotropic agent, an acyclic amide compound that is an aggregate of monoamides connected by an interaction by hydrogen bonding is connected via the cyclic amide compound.

  In a solder paste using a flux in which the thixotropic agent includes a cyclic amide compound and an acyclic amide compound, thixotropic properties are considered to be imparted by forming a network between the cyclic amide compound and the acyclic amide compound.

  However, if the content of the cyclic amide compound and the non-cyclic amide compound is too small, a sufficient network cannot be formed, so that thixotropy is not imparted.

  On the other hand, in a thixotropic agent that does not contain a cyclic amide compound or contains less cyclic amide compound than the amount specified in the present invention, if the acyclic amide compound is excessive, the intramolecular and intermolecular amounts of the acyclic amide compound are increased. In this case, the particles are excessively interacted with each other, and aggregation / precipitation is likely to occur.

  As a result, the rheological properties as a flux are impaired (the printability due to crystal precipitation is poor), and the density of the thixotropic agent is low at the portion where the aggregate is not formed, and the thixotropic agent is substantially insufficient as described above. It is considered that it becomes impossible to demonstrate the effect.

  On the other hand, dicarboxylic acid and / or tricarboxylic acid, cyclic amide compound in which diamine and / or triamine are polycondensed cyclically, monocarboxylic acid, dicarboxylic acid and / or tricarboxylic acid, monoamine, diamine and / or triamine By using together a non-cyclic amide compound condensed in a non-cyclic manner at a content specified in the present invention, the non-cyclic amide compound is cross-linked by a non-covalent interaction with the cyclic amide compound, and is relatively uniform. A network of thixotropic agent components can be constructed to suppress excessive thixotropic agent precipitation. As long as the content of the cyclic amide compound and the non-cyclic amide compound is within the range specified by the present invention, the effect of combining the cyclic amide compound and the non-cyclic amide compound is that even if the molecular weight of the non-cyclic amide compound is 3000 or less. It is also demonstrated at over 3000.

  In addition, if the ratio of the total number of moles of the carboxyl group of dicarboxylic acid and / or tricarboxylic acid to the total number of moles of the amino group of diamine and / or triamine is 1: 1, the acyclic amide compound has a maximum molecular weight. Become. On the other hand, if the ratio of the total number of moles of carboxyl groups of dicarboxylic acid and / or tricarboxylic acid to the total number of moles of amino groups of diamine and / or triamine is 1: m or m: 1 (m> 1). It becomes an acyclic amide oligomer having a small molecular weight. Preferably it is 1: 2 to 2: 1.

  In the cyclic amide compound, the dicarboxylic acid and the tricarboxylic acid have 3 to 10 carbon atoms, and the dicarboxylic acid and the tricarboxylic acid have 6 to 10 carbon atoms.

  Moreover, as for a cyclic amide compound, it is more preferable that carbon number of diamine and a triamine is 2 or more and 54 or less, and carbon number of a diamine and a triamine is 6.

  Further, in the acyclic amide compound, the monocarboxylic acid, dicarboxylic acid and tricarboxylic acid preferably have 2 to 28 carbon atoms, and the monocarboxylic acid, dicarboxylic acid and tricarboxylic acid preferably have 2 or more carbon atoms. 18 or less, more preferably 2 or more and 10 or less, and still more preferably 6 or more and 10 or less. The acyclic amide compound preferably has 0 to 54 carbon atoms of monoamine, diamine and triamine, more preferably 0 to 18 carbon atoms, still more preferably 0 to 10 carbon atoms. More preferably, it is 6 or more and 10 or less.

  Examples of the dicarboxylic acid in the cyclic amide compound and the non-cyclic amide compound include adipic acid having 6 carbon atoms and sebacic acid having 10 carbon atoms.

  The dicarboxylic acid in the cyclic amide compound and the non-cyclic amide compound is malonic acid having 3 carbon atoms, succinic acid having 4 carbon atoms, glutaric acid having 5 carbon atoms, pimelic acid having 7 carbon atoms, suberic acid having 8 carbon atoms, Examples thereof include aliphatic dicarboxylic acids such as azelaic acid having 9 carbon atoms and cyclohexanedicarboxylic acid having 8 carbon atoms, and aromatic dicarboxylic acids such as phthalic acid having 6 carbon atoms and terephthalic acid having 6 carbon atoms.

  Furthermore, examples of the tricarboxylic acid in the cyclic amide compound and the non-cyclic amide compound include cyclohexane tricarboxylic acid having 9 carbon atoms and benzene tricarboxylic acid having 9 carbon atoms.

  In addition, the monocarboxylic acid in the acyclic amide compound includes acetic acid having 2 carbon atoms, palmitic acid having 16 carbon atoms, stearic acid having 18 carbon atoms, 12-hydroxystearic acid having 18 carbon atoms, behenic acid having 22 carbon atoms, carbon Examples include montanic acid of formula 28.

  Examples of the diamine in the cyclic amide compound and the non-cyclic amide compound include 1,6-hexanediamine.

  The diamines in the cyclic amide compound and the non-cyclic amide compound are ethylene diamine having 2 carbon atoms, 1,3-diaminopropane having 3 carbon atoms, 1,4-diaminobutane having 4 carbon atoms, dimer diamine having 36 carbon atoms, carbon Examples thereof include phenylenediamine having 6 carbon atoms, metaxylylenediamine having 8 carbon atoms, paraxylylenediamine having 8 carbon atoms, and 2,4-diaminotoluene having 8 carbon atoms.

  Furthermore, examples of the triamine in the cyclic amide compound and the non-cyclic amide compound include a triaminocyclohexane having 6 carbon atoms and a trimeric triamine having 54 carbon atoms.

  Examples of the monoamine in the acyclic amide compound include ammonia having 0 carbon atoms, ethylamine having 2 carbon atoms, hexylamine having 6 carbon atoms, octylamine having 8 carbon atoms, and stearylamine having 18 carbon atoms.

  Examples of the [1 + 1] -type acyclic amide compound obtained by condensing a monocarboxylic acid and a monoamine include stearic acid amide and p-toluamide. Moreover, ethylenediamine monostearic acid amide etc. are mentioned as a [1 + 1] type acyclic amide compound which monocarboxylic acid and diamine condensed.

  Examples of the [2 + 1] type acyclic amide compound in which monocarboxylic acid and diamine are condensed include ethylenediamine bisstearic acid amide, ethylenediamine bispalmitic acid amide, metaxylylenediamine bisstearic acid amide, and the like.

  Examples of the [1 + 2] type acyclic amide compound in which dicarboxylic acid and monoamine are condensed include succinic acid bisstearylamide, adipic acid bisstearylamide, sebacic acid bisstearylamide, and the like.

  The acyclic amide compound may be substituted even by ring-opening polymerization of lactam, and examples thereof include 6-nylon obtained by ring-opening polymerization of ε-caprolactam and 12-nylon obtained by ring-opening polymerization of lauryl lactam.

  The flux of the present embodiment is 0.1 wt% or more and 8.0 wt% or less of the cyclic amide compound described above as the thixotropic agent, more preferably 0.5 wt% or more and 1.5 wt% or less of the cyclic amide compound. 0.5 wt% or more and 8.0 wt% or less of the compound, more preferably 0.5 wt% or more and 4.0 wt% or less of the acyclic amide compound, and the total of the cyclic amide compound and the acyclic amide compound is 1.5 wt% % To 10.0 wt%.

  If the amount of the cyclic amide compound is less than 0.1 wt%, the thixotropy is deteriorated. Further, it is not possible to suppress printing sag and heating sag. On the other hand, when the amount of the cyclic amide compound is more than 8.0 wt%, the total amount of the amide-based thixotropic agent is increased, so that precipitation occurs in the flux and printability is deteriorated. Even if the amount of the cyclic amide compound is 0.1 wt%, if the total of the cyclic amide compound and the acyclic amide compound is less than 1.5 wt%, the thixotropy is deteriorated. Further, it is not possible to suppress printing sag and heating sag. In addition, even if the amount of the cyclic amide compound is less than 0.1 wt%, if the content of the acyclic amide compound is increased, thixotropy, printing sag, and heat sag are improved, but precipitation occurs in the flux, Printability deteriorates.

  Further, the flux of the present embodiment contains 5.0 wt% or more and 50.0 wt% or less of acid-modified rosin. The acid-modified rosin has heat resistance in a temperature range assumed for soldering and functions as an activator during soldering. When the content of the acid-modified rosin is less than 5.0 wt%, the solder wetting rate decreases. Examples of the acid-modified rosin include acrylic acid-modified rosin, acrylic acid-modified hydrogenated rosin, maleic acid-modified rosin, and maleic acid-modified hydrogenated rosin, and one or more of these can be used.

  The flux of the present embodiment contains other rosins other than acid-modified rosin in an amount of 0 wt% to 50 wt%, more preferably 25 wt% to 45 wt%. When the content of other rosins exceeds 0 wt%, the total content of the acid-modified rosin and other rosins is 60 wt% or less.

  Examples of other rosins include raw material rosins such as gum rosin, wood rosin and tall oil rosin, and derivatives obtained from the raw rosin. Examples of the derivatives include purified rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, phenol-modified rosin and α, β-unsaturated carboxylic acid-modified products (acrylic rosin, maleated rosin, fumarated rosin, etc.), And a purified product, a hydride and a disproportionate of the polymerized rosin, and a purified product, a hydride and a disproportionate of the α, β-unsaturated carboxylic acid modified product. Can be used.

  The flux of the present embodiment may further contain an organic acid, an amine, and a halogen. The organic acid is 0 wt% or more and 10 wt% or less, more preferably, the organic acid is 0.2 wt% or more and 5 wt% or less, and the amine is 0 wt%. % To 20 wt%, more preferably 0 to 5 wt% of amine, 0 to 5 wt% of organic halogen compound as halogen, and 0 to 2 wt% of amine hydrohalide.

  The flux of the present embodiment may contain an ester compound as a thixotropic agent, and contains 0 wt% or more and 8.0 wt% or less of the ester compound, more preferably 0 wt% or more and 4.0 wt% or less.

  The flux of the present embodiment may further contain an antioxidant, and contains 0 wt% or more and 5 wt% or less of the antioxidant. The balance of the flux of the present embodiment is a solvent.

  Organic acids include glutaric acid, adipic acid, azelaic acid, eicosane diacid, citric acid, glycolic acid, succinic acid, salicylic acid, diglycolic acid, dipicolinic acid, dibutylaniline diglycolic acid, suberic acid, sebacic acid, thioglycol Acid, terephthalic acid, dodecanedioic acid, parahydroxyphenylacetic acid, picolinic acid, phenylsuccinic acid, phthalic acid, fumaric acid, maleic acid, malonic acid, lauric acid, benzoic acid, tartaric acid, tris (2-carboxyethyl) isocyanurate Glycine, 1,3-cyclohexanedicarboxylic acid, 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (hydroxymethyl) butanoic acid, 2,3-dihydroxybenzoic acid, 2,4-diethylglutaric acid 2-quinolinecarboxylic acid, 3-hydroxybenzoic acid, malic acid, - anisic acid, stearic acid, 12-hydroxystearic acid, oleic acid, linoleic acid, and linolenic acid.

  Examples of the organic acid include dimer acid that is a dimer of a reaction product of monocarboxylic acid, hydrogenated dimer acid obtained by adding hydrogen to dimer acid, trimer acid that is a trimer of a reaction product of monocarboxylic acid, and trimer acid. Examples thereof include hydrogenated trimer acid obtained by adding hydrogen to an acid.

  Dimer acid and trimer acid are 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, dimer acid which is a reaction product of acrylic acid, and a reaction product of acrylic acid. Dimer acid, a reaction product of trimer acid, methacrylic acid, trimer acid, a reaction product of methacrylic acid, dimer acid, a reaction product of acrylic acid and methacrylic acid, trimer acid, a reaction product of acrylic acid and methacrylic acid, olein Dimer acid that is a reaction product of acid, trimer acid that is a reaction product of oleic acid, dimer acid that is a reaction product of linoleic acid, trimer acid that is a reaction product of linoleic acid, dimer acid that is a reaction product of linolenic acid, linolenic acid Trimer acid that is a reaction product of acid, dimer acid that is a reaction product of acrylic acid and oleic acid, and a reaction product of acrylic acid and oleic acid. Trimer acid, dimer acid which is a reaction product of acrylic 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, reaction of acrylic acid and linolenic acid Trimer acid, a reaction product of methacrylic acid and oleic acid, dimer acid, a reaction product of methacrylic acid and oleic acid, dimer acid, a reaction product of methacrylic acid and linoleic acid, methacrylic acid and linoleic acid Trimer acid, reaction product of methacrylic acid and linolenic acid, dimer acid, reaction product of methacrylic acid and linolenic acid, dimer acid, reaction product of oleic acid and linolenic acid, and oleic acid Trimer acid, a reaction product of linolenic acid, dimer acid, a reaction product of linoleic acid and linolenic acid, and linoleic acid Trimer acid is a reaction product of alkylene acid, hydrogenated dimer acid which is a hydrogenation product of the dimer acid as described above, hydrogenated trimer acid, and the like are hydrogenated products of the trimer acid described above. For example, dimer acid, which is a reaction product of oleic acid and linoleic acid, is a dimer having 36 carbon atoms. Further, trimer acid, which is a reaction product of oleic acid and linoleic acid, is a trimer having 54 carbon atoms.

  Examples of amines include monoethanolamine, diphenylguanidine, ethylamine, triethylamine, ethylenediamine, triethylenetetramine, 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, and 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-ethylpentyl) benzimidazole, 2-nonylbenzimidazole, 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, 3-dicarboxypropyl) benzotriazole, 1-[(2-ethylhexylamino) methyl] benzotriazole, 2,6-bis [(1H-benzotriazol-1-yl) methyl] -4-methylphenol, 5-methyl Examples include benzotriazole and 5-phenyltetrazole.

  Examples of the organic halogen compound include trans-2,3-dibromo-1,4-butenediol, 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, and the like.

  An amine hydrohalide is a compound obtained by reacting an amine with a hydrogen halide, and examples thereof include aniline hydrogen chloride and aniline hydrogen bromide. As the amine of the amine hydrohalide, the above-described amines can be used, and examples include ethylamine, ethylenediamine, triethylamine, methylimidazole, 2-ethyl-4-methylimidazole, and the like. Examples include hydrides of bromine, iodine, and fluorine (hydrogen chloride, hydrogen bromide, hydrogen iodide, hydrogen fluoride). Further, a borofluoride may be included instead of the amine hydrohalide or together with the amine hydrohalide, and examples of the borofluoride include borohydrofluoric acid.

  Examples of the solvent include water, alcohol solvents, glycol ether solvents, terpineols and the like. As alcohol solvents, isopropyl alcohol, 1,2-butanediol, isobornylcyclohexanol, 2,4-diethyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, 2,5 -Dimethyl-2,5-hexanediol, 2,5-dimethyl-3-hexyne-2,5-diol, 2,3-dimethyl-2,3-butanediol, 1,1,1-tris (hydroxymethyl) Ethane, 2-ethyl-2-hydroxymethyl-1,3-propanediol, 2,2'-oxybis (methylene) bis (2-ethyl-1,3-propanediol), 2,2-bis (hydroxymethyl) -1,3-propanediol, 1,2,6-trihydroxyhexane, bis [2,2,2-tris (hydroxymethyl) ethyl] ate 1-ethynyl-1-cyclohexanol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, erythritol, threitol, guaiacol glycerol ether, 3,6-dimethyl-4-octyne-3,6-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol and the like. Examples of the glycol ether solvent include hexyl diglycol, diethylene glycol mono-2-ethylhexyl ether, ethylene glycol monophenyl ether, 2-methylpentane-2,4-diol, diethylene glycol dibutyl ether, and triethylene glycol monobutyl ether. Examples of the ester compound as a thixotropic agent include castor oil. Examples of the antioxidant include hindered phenol antioxidants.

<Example of solder paste of this embodiment>
The solder paste of the present embodiment includes the above-described flux and metal powder. The metal powder may be Sn powder of Sn alone, Sn—Ag, Sn—Cu, Sn—Ag—Cu, Sn—Bi, Sn—In, etc., or an alloy of these with Sb, Bi, In, Cu, Zn, As, Ag, Cd, Fe, Ni, Co, Au, Ge, P, Pb, etc. are used to form a solder alloy powder.

  The solder alloy has As: 25 mass ppm to 300 mass ppm, Sb: more than 0 mass ppm to 3000 mass ppm, Bi: more than 0 mass ppm to 10000 mass ppm, and Pb: more than 0 mass ppm to less than 5100 mass ppm. It is preferable to have an alloy composition of at least one kind and the balance being Sn. The solder alloy may further contain at least one of Ag: 0% by mass to 4% by mass and Cu: 0% by mass to 0.9% by mass.

  As is an element that can suppress the change with time of the viscosity of the solder paste. It is presumed that As has a low reactivity with the flux and is a noble element with respect to Sn, and thus can exhibit a thickening suppressing effect. The lower limit of the As content is, for example, 25 ppm by mass or more, preferably 50 ppm by mass or more, and more preferably 100 ppm by mass or more. On the other hand, when there is too much As, the wettability of the solder alloy deteriorates. The upper limit of As content is 300 mass ppm or less, for example, Preferably it is 250 mass ppm or less, More preferably, it is 200 mass ppm or less.

  Sb is an element that has low reactivity with the flux and exhibits a thickening suppressing effect. When the solder alloy contains Sb, the lower limit of the Sb content is, for example, more than 0 ppm by mass, preferably 25 ppm by mass or more, more preferably 50 ppm by mass or more, and further preferably 100 ppm by mass or more. Especially preferably, it is 300 mass ppm or more. On the other hand, if the Sb content is too large, the wettability deteriorates, so it is necessary to adjust the content appropriately. The upper limit of Sb content is 3000 mass ppm or less, for example, Preferably it is 1150 mass ppm or less, More preferably, it is 500 mass ppm or less.

  Bi and Pb are elements that have a low reactivity with the flux and exhibit a thickening suppressing effect, as in Sb. Bi and Pb are elements that can suppress deterioration of wettability due to As in order to lower the liquidus temperature of the solder alloy and reduce the viscosity of the molten solder.

  If at least one element of Sb, Bi and Pb is present, deterioration of wettability due to As can be suppressed. When the solder alloy contains Bi, the lower limit of the Bi content is, for example, more than 0 ppm by mass, preferably 25 ppm by mass or more, more preferably 50 ppm by mass or more, and further preferably 75 ppm by mass or more. And is particularly preferably 100 ppm by mass or more, and most preferably 250 ppm by mass or more. When the solder alloy contains Pb, the lower limit of the Pb content is more than 0 ppm by mass, preferably 25 ppm by mass or more, more preferably 50 ppm by mass or more, and further preferably 75 ppm by mass or more. Particularly preferred is 100 ppm by mass or more, and most preferred is 250 ppm by mass or more.

  On the other hand, if the content of these elements is too large, the solidus temperature is remarkably lowered, so that ΔT, which is the temperature difference between the liquidus temperature and the solidus temperature, becomes too wide. If ΔT is too wide, a liquid phase Bi or Pb is concentrated because a high melting point crystal phase with a small content of Bi or Pb is precipitated in the solidification process of the molten solder. Thereafter, when the temperature of the molten solder further decreases, a low melting point crystal phase having a high concentration of Bi or Pb is segregated. For this reason, the mechanical strength and the like of the solder alloy are deteriorated, and the reliability is inferior. In particular, since the crystal phase with a high Bi concentration is hard and brittle, the segregation in the solder alloy significantly reduces the reliability.

  From such a viewpoint, when the solder alloy contains Bi, the upper limit of the Bi content is, for example, 10000 mass ppm or less, preferably 1000 mass ppm or less, more preferably 600 mass ppm or less, Preferably it is 500 mass ppm or less. When the solder alloy contains Pb, the upper limit of the Pb content is, for example, 5100 mass ppm or less, preferably 5000 mass ppm or less, more preferably 1000 mass ppm or less, and even more preferably 850 mass ppm or less. And particularly preferably 500 ppm by mass or less.

  The solder alloy preferably satisfies the following formula (1).

275 ≦ 2As + Sb + Bi + Pb (1)
In the above formula (1), As, Sb, Bi, and Pb each represent the content (mass ppm) in the alloy composition.

  As, Sb, Bi, and Pb are all elements that exhibit a thickening suppressing effect. The total of these is preferably 275 ppm by mass or more. The reason why the As content is doubled in the equation (1) is that As has a higher viscosity-inhibiting effect than Sb, Bi, and Pb.

  The lower limit of the formula (1) is preferably 350 or more, more preferably 1200 or more. On the other hand, the upper limit of (1) is not particularly limited in terms of the effect of suppressing thickening, but is preferably 25200 or less, more preferably 10200 or less, from the viewpoint of making ΔT a suitable range. More preferably, it is 5300 or less, Most preferably, it is 3800 or less.

  Those in which the upper limit and the lower limit are appropriately selected from the above preferred embodiments are the following formulas (1a) and (1b).

275 ≦ 2As + Sb + Bi + Pb ≦ 25200 (1a)
275 ≦ 2As + Sb + Bi + Pb ≦ 5300 (1b)
In the above formulas (1a) and (1b), As, Sb, Bi, and Pb each represent the content (mass ppm) in the alloy composition.

  The solder alloy preferably satisfies the following formula (2).

0.01 ≦ (2As + Sb) / (Bi + Pb) ≦ 10.00 (2)
In the above formula (2), As, Sb, Bi, and Pb each represent the content (mass ppm) in the alloy composition.

  When the content of As and Sb is large, the wettability of the solder alloy deteriorates. On the other hand, Bi and Pb suppress deterioration of wettability due to containing As, but if the content is too large, ΔT increases. In particular, in an alloy composition containing Bi and Pb simultaneously, ΔT tends to increase. In view of these, if the Bi and Pb contents are increased to excessively improve the wettability, ΔT spreads. On the other hand, when the content of As or Sb is increased to improve the thickening suppressing effect, the wettability deteriorates. Therefore, when it is divided into the group of As and Sb and the group of Bi and Pb, and the total amount of both groups is within an appropriate predetermined range, the thickening suppression effect, the narrowing of ΔT, and the wettability are all simultaneously. It is satisfied.

  If the formula (2) is less than 0.01, the total content of Bi and Pb is relatively larger than the total content of As and Pb, and therefore ΔT spreads. The lower limit of the formula (2) is preferably 0.02 or more, more preferably 0.41 or more, further preferably 0.90 or more, particularly preferably 1.00 or more, and most preferably. Is 1.40 or more. On the other hand, if the formula (2) exceeds 10.00, the sum of the contents of As and Sb becomes relatively larger than the sum of the contents of Bi and Pb, so that the wettability deteriorates. The upper limit of (2) is preferably 5.33 or less, more preferably 4.50 or less, still more preferably 2.67 or less, and particularly preferably 2.30 or less.

  The denominator of the equation (2) is “Bi + Pb”, and the equation (2) is not established unless these are included. Therefore, it is preferable that the solder alloy contains at least one of Bi and Pb. The alloy composition not containing Bi and Pb has poor wettability as described above.

  What selected the upper limit and the lower limit appropriately from the above preferred embodiments is the following formula (2a).

0.31 ≦ (2As + Sb) / (Bi + Pb) ≦ 10.00 (2a)
In the above formula (2a), As, Sb, Bi and Pb each represent the content (mass ppm) in the alloy composition.

  Ag is an optional element that can improve the reliability of the solder alloy by forming Ag3Sn at the crystal interface. Further, Ag is an element having an ionization coefficient that is noble with respect to Sn, and promotes these thickening suppressing effects by coexisting with As, Pb, and Bi. The Ag content is preferably 0% by mass to 4% by mass, more preferably 0.5% by mass to 3.5% by mass, and still more preferably 1.0% by mass to 3.0% by mass. It is.

  Cu is an optional element that can improve the joint strength of the solder joint. Further, Cu is an element having an ionization coefficient that is noble with respect to Sn, and coexists with As, Pb, and Bi to promote these thickening suppressing effects. The Cu content is preferably 0% by mass to 0.9% by mass, more preferably 0.1% by mass to 0.8% by mass, and further preferably 0.2% by mass to 0.7% by mass. % Or less.

  The balance of the solder alloy is preferably Sn. The solder alloy may contain inevitable impurities in addition to the aforementioned elements. Even when inevitable impurities are contained, the above-mentioned effects are not affected. If the content of In is too large, ΔT spreads. Therefore, if the content is 1000 ppm by mass or less, the above-described effects are not affected.

<Examples of effects of flux and solder paste of this embodiment>
Thixotropic agent, dimer acid, hydrogenated dimer acid, trimer acid, hydrogenated trimer acid, or two or more of dimer acid, hydrogenated dimer acid, trimer acid, hydrogenated trimer acid, rosin, solvent The thixotropic agent is a flux comprising a cyclic amide compound and a non-cyclic amide compound, and thixotropy can be increased without increasing the content of the non-cyclic amide compound compared to the case where the thixotropic agent is comprised of a non-cyclic amide compound. It can be improved, and precipitation of thixotropic agents can be suppressed. With the solder paste using this flux, it is possible to obtain good printability in which bleeding, blurring and the like are suppressed, and it is possible to suppress printing sag through which the solder paste after printing flows. Furthermore, the heating sag of the solder paste due to heating during soldering can be suppressed.

  The acid-modified rosin has heat resistance in the temperature range assumed for soldering and functions as an activator during soldering. Thereby, in the flux containing acid-modified rosin and the solder paste using this flux, the wetting speed of the solder is improved and a desired wetting speed is obtained.

  In the compositions shown in Table 1, Table 2, and Table 3 below, the fluxes of Examples and Comparative Examples are prepared, and the solder paste is prepared using this flux to suppress the thixotropy of the flux and the printing sag of the solder paste. Performance, printability, ability to suppress heat sag, and solder wetting speed. In addition, the composition ratio in Table 1, Table 2, and Table 3 is wt (weight)% when the total amount of flux is 100.

  The solder paste has a flux of 11.0 wt% and metal powder of 89.0 wt%. Further, the metal powder in the solder paste is Sn-Ag-Cu based solder alloy in which Ag is 3.0% by mass, Cu is 0.5% by mass and the balance is Sn when the total amount of the metal powder is 100. The average particle diameter of the metal powder is φ20 μm.

<Evaluation of flux thixotropy>
(1) Verification method The thixotropy was evaluated using a spiral viscometer in accordance with JIS Z3284-3 4.2. The rotation speed of the viscometer was set to 3 rpm and 30 rpm, the viscosity after rotation for a predetermined time was read, and the thixo ratio was calculated.

(2) Criteria 〇〇: Thixo ratio is 0.60 or more 〇: Thixo ratio is 0.30 or more and less than 0.60 ×: Thixo ratio is less than 0.30

<Evaluation of printing sag suppression ability of solder paste>
(1) Verification method The evaluation of the ability to suppress the printing sag of the solder paste is based on JIS Z3284-3 4.3, using a stainless steel metal mask in which the solder paste printing part is formed with a predetermined pattern on the copper plate. After the paste is printed and the metal mask is removed, it is stored at room temperature 25 ± 5 ° C. and relative humidity 50 ± 10% for 10-20 minutes. Of the printed patterns, all the printed solder pastes are not integrated. The minimum spacing was confirmed visually. The thickness of the metal mask is 0.2 mm, the solder paste printing part is a rectangular opening, and the size is 3.0 × 1.5 mm. In the solder paste printing section, a plurality of openings of the same size are arranged at different intervals, and the interval L of the openings is 0.2-0.3-0.4-0.5-0.6-0.7- 0.8-0.9-1.0-1.1-1.2 mm.

(2) Judgment criteria ○: Minimum interval that does not become integrated after printing is 0.2 mm or less ×: Minimum interval that does not become integrated after printing exceeds 0.2 mm

<Evaluation of printability of solder paste>
(1) Verification method The evaluation of the printability of the solder paste is based on JIS Z3284-3 4.1, and the solder paste is applied to the copper plate using a stainless steel metal mask in which the solder paste printing part is formed in a predetermined pattern. After printing, it was visually confirmed whether there was any blur or blurring at the initial printing stage or during continuous printing.

(2) Criteria ◯: No smearing or blurring after printing ×: Smearing or blurring after printing

<Evaluation of heat sag suppression ability of solder paste>
(1) Verification method The evaluation of the heat sag suppressing ability of the solder paste is based on JIS Z3284-3 4.4, and the solder is applied to the copper plate using a stainless steel metal mask in which the solder paste printing part is formed with a predetermined pattern. After the paste was printed and the metal mask was removed, heating was performed at 150 ± 10 ° C. for 10 minutes, and among the printed patterns, the minimum interval at which all the printed solder paste was not integrated was visually confirmed. The thickness of the metal mask is 0.2 mm, the solder paste printing part is a rectangular opening, and the size is 3.0 × 1.5 mm. In the solder paste printing section, a plurality of openings of the same size are arranged at different intervals, and the interval L of the openings is 0.2-0.3-0.4-0.5-0.6-0.7- 0.8-0.9-1.0-1.1-1.2 mm.

(2) Criteria ◯: Minimum interval not integrated is 1.0 mm or less ×: Minimum interval not integrated is over 1.0 mm

<Evaluation of wetting speed>
(1) Verification method For evaluating the wetting rate, a flux was applied to a copper oxide plate, and the zero cross time was measured by the menisograph method. The measurement conditions are as follows.

Solid sample: copper oxide plate, width 5 mm × length 25 mm, thickness 0.5 mm, 150 ° C. 1 h
Solder composition: Sn-3.0Ag-0.5Cu (Sn 96.5 wt%, Ag 3.0 wt%, Cu 0.5 wt%)
Solder bath temperature: 250 ° C. JIS Z 3198-4
Immersion speed: 5 mm / sec JIS Z 3198-4
Immersion depth: 2mm JIS Z 3198-4
Measurement time: 10 sec JIS Z 3198-4
Flux application amount: Flux application at the needle tip so that the flux covers the surface of the copper oxide plate until the immersion depth of the copper oxide plate is 3 mm

(2) Criteria ◯: Zero cross time value was 2.5 seconds or less.
X: The zero cross time value was more than 2.5 seconds.

<Comprehensive evaluation>
○: Evaluation of flux thixotropy ○○ or ○, evaluation of solder paste printing sag suppression ability, evaluation of solder paste printing ability, evaluation of solder paste heating sag suppression ability, evaluation of solder wetting speed ×: Evaluation of flux thixotropy, evaluation of solder paste print sag suppression, evaluation of solder paste printability, evaluation of solder paste heat sag suppression, evaluation of solder wetting speed Any or all of was X

  Examples 1 to 3 were obtained by changing the amount of acid-modified rosin. In Example 1, acrylic acid-modified rosin was contained as an acid-modified rosin within a range defined by the present invention, and contained 25.0 wt%. As another rosin, a polymerized rosin is contained at 25.0 wt% within the range defined by the present invention. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as the thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid, which is a dicarboxylic acid having 10 carbon atoms, and 1,6-hexanediamine, which is a diamine having 6 carbon atoms, is defined in the present invention. An acyclic amide compound in which sebacic acid, which is 2.0% by weight within the range, is a dicarboxylic acid having 10 carbon atoms, and 1,6-hexanediamine, which is a diamine having 6 carbon atoms, is acyclically condensed. The content is 4.0 wt% within the range specified in the invention. The total content of the cyclic amide compound and the non-cyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. 44.0 wt% of tetraethylene glycol monomethyl ether is contained within the range defined by the present invention with the balance being the solvent.

  In Example 1, the thixo ratio was 0.60 or more, the thixotropy of the flux could be improved, a sufficient effect on the thixotropy was obtained, and precipitation of the thixotropic agent could be suppressed. Moreover, in the solder paste using this flux, the minimum gap that is not integrated after printing is 0.2 mm or less, and it is possible to suppress the printing sag through which the solder paste after printing flows, and to suppress the printing sag of the solder paste. A sufficient effect on the performance was obtained. Further, after printing, no blur or blur was observed, and good printability with suppressed blur, blur and the like was obtained, and a sufficient effect on printability was obtained. In addition, the minimum gap that is not integrated after heating is 1.0 mm or less, and it is possible to suppress the heating sagging of the solder paste due to the heating at the time of soldering, and a sufficient effect is obtained for the ability to suppress the heating sagging. It was. Furthermore, when the zero cross time value was 2.5 seconds or less, the wetting rate satisfied the above-described criteria, and a sufficient effect on the wetting rate was obtained.

  In Example 2, an acrylic acid-modified rosin is added as an acid-modified rosin within the range defined by the present invention, and 50.0 wt% is contained, and no other rosin is contained. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total content of the cyclic amide compound and the non-cyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. 44.0 wt% of tetraethylene glycol monomethyl ether is contained within the range defined by the present invention with the balance being the solvent.

  In Example 2, by increasing the content of the acid-modified rosin within the range defined by the present invention, a sufficient effect on thixotropy was obtained even if other rosins were not included. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 3, the acrylic acid-modified rosin is reduced as the acid-modified rosin within the range defined by the present invention to include 5.0 wt%, and the hydrogenated rosin as the other rosin is within the range defined by the present invention. Contains 45.0 wt%. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total content of the cyclic amide compound and the non-cyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. 44.0 wt% of tetraethylene glycol monomethyl ether is contained within the range defined by the present invention with the balance being the solvent.

  In Example 3, even if the content of the acid-modified rosin was reduced within the range defined by the present invention, a sufficient effect on thixotropy was obtained by including other rosins. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Examples 4 to 6, the kind of acid-modified rosin was changed. In Example 4, acrylic acid-modified hydrogenated rosin was used as the acid-modified rosin within the range defined by the present invention, and the content was 25.0 wt%. In addition, 25.0 wt% of a polymerized rosin is contained within the range defined by the present invention as another rosin. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total content of the cyclic amide compound and the non-cyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. 44.0 wt% of tetraethylene glycol monomethyl ether is contained within the range defined by the present invention with the balance being the solvent.

  Also in Example 4, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 5, maleic acid-modified rosin is contained as an acid-modified rosin within a range specified by the present invention in an amount of 25.0 wt%, and polymerized rosin as another rosin within a range specified by the present invention is 25.0 wt%. % Is included. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total content of the cyclic amide compound and the non-cyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. 44.0 wt% of tetraethylene glycol monomethyl ether is contained within the range defined by the present invention with the balance being the solvent.

  Also in Example 5, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 6, maleic acid-modified hydrogenated rosin was contained as an acid-modified rosin in an amount of 25.0 wt% within the range specified by the present invention, and polymerized rosin was added as another rosin within the range specified by the present invention. 0.0wt% is included. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. The non-cyclic polycondensed non-cyclic amide compound is contained in an amount of 4.0 wt% within the range specified in the present invention. The total content of the cyclic amide compound and the non-cyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. 44.0 wt% of tetraethylene glycol monomethyl ether is contained within the range defined by the present invention with the balance being the solvent.

  Also in Example 6, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 7, acid-modified rosin was added in combination. As acid-modified rosin, acrylic acid-modified rosin was used within the range defined by the present invention, and 10.0 wt% acrylic acid-modified hydrogenated rosin. 5.0 wt% maleic acid-modified rosin within the specified range, 5.0 wt% maleic acid-modified hydrogenated rosin within the range specified by the present invention, and 5. within the range specified by the present invention. Contains 0 wt%. The total content of acid-modified rosin is 25 wt%, and is within the range defined by the present invention. Moreover, 25.0 wt% of polymerized rosins are contained in the range prescribed | regulated by this invention as another rosin. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total content of the cyclic amide compound and the non-cyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. 44.0 wt% of tetraethylene glycol monomethyl ether is contained within the range defined by the present invention with the balance being the solvent.

  Also in Example 7, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  Examples 8 to 10 are obtained by changing the kind of acid-modified rosin and adding other rosin in combination. In Example 8, acrylic acid-modified hydrogenated rosin is defined as the acid-modified rosin in the present invention. 25.0 wt% in the range. Further, as other rosin, polymerized rosin, 10.0 wt% within the range specified in the present invention, hydrogenated rosin, 10.0 wt% within the range specified by the present invention, disproportionated rosin, 5.0 wt% is included within the range specified by the invention. The total content of other rosins is 25 wt%, and is within the range defined by the present invention. The total content of the acid-modified rosin and other rosins is 50.0 wt%, which is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total content of the cyclic amide compound and the non-cyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. 44.0 wt% of tetraethylene glycol monomethyl ether is contained within the range defined by the present invention with the balance being the solvent.

  In Example 8, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 9, 25.0 wt% of maleic acid-modified rosin is contained as the acid-modified rosin within the range defined by the present invention. Further, as other rosin, polymerized rosin, 10.0 wt% within the range specified in the present invention, hydrogenated rosin, 10.0 wt% within the range specified by the present invention, disproportionated rosin, 5.0 wt% is included within the range specified by the invention. The total content of other rosins is 25 wt%, and is within the range defined by the present invention. The total content of the acid-modified rosin and other rosins is 50.0 wt%, which is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total content of the cyclic amide compound and the non-cyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. 44.0 wt% of tetraethylene glycol monomethyl ether is contained within the range defined by the present invention with the balance being the solvent.

  Even in Example 9, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 10, maleic acid-modified hydrogenated rosin is contained as an acid-modified rosin within a range specified by the present invention at 25.0 wt%. Further, as other rosin, polymerized rosin, 10.0 wt% within the range specified in the present invention, hydrogenated rosin, 10.0 wt% within the range specified by the present invention, disproportionated rosin, 5.0 wt% is included within the range specified by the invention. The total content of other rosins is 25 wt%, and is within the range defined by the present invention. The total content of the acid-modified rosin and other rosins is 50.0 wt%, which is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total content of the cyclic amide compound and the non-cyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. 44.0 wt% of tetraethylene glycol monomethyl ether is contained within the range defined by the present invention with the balance being the solvent.

  Even in Example 10, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 11, acid-modified rosin and other rosins were added in combination. As the acid-modified rosin, acrylic acid-modified rosin was added within the range specified by the present invention, and 10.0 wt% acrylic acid-modified hydrogenated rosin. Within the range specified by the present invention, 5.0 wt% maleic acid-modified rosin, within the range specified by the present invention 5.0 wt% maleic acid-modified hydrogenated rosin, the range specified by the present invention Including 5.0 wt%. The total content of acid-modified rosin is 25 wt%, and is within the range defined by the present invention. Further, as other rosin, polymerized rosin, 10.0 wt% within the range specified in the present invention, hydrogenated rosin, 10.0 wt% within the range specified by the present invention, disproportionated rosin, 5.0 wt% is included within the range specified by the invention. The total content of other rosins is 25 wt%, and is within the range defined by the present invention. Furthermore, the total content of acid-modified rosin and other rosins is 50.0 wt%, which is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total content of the cyclic amide compound and the non-cyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. 44.0 wt% of tetraethylene glycol monomethyl ether is contained within the range defined by the present invention with the balance being the solvent.

  Even in Example 11, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 12, an organic acid was added, and acrylic acid-modified rosin was contained as an acid-modified rosin within a range defined by the present invention in an amount of 25.0 wt%, and polymerized rosin was defined as another rosin according to the present invention. Within the range, 25.0 wt% is included. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total content of the cyclic amide compound and the non-cyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. Further, glutaric acid is included as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the remainder as a solvent includes tetraethylene glycol monomethyl ether within a range specified by the present invention as 41.0 wt%.

  Also in Example 12, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Examples 13 and 14, the addition amount of the cyclic amide compound and the non-cyclic amide compound was changed. In Example 13, acrylic acid-modified rosin was used as the acid-modified rosin within the range defined by the present invention. It contains 25.0 wt%, and polymerized rosin as another rosin is contained within the range specified in the present invention, 25.0 wt%. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as the thixotropic agent, 0.5% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. The non-cyclic amide compound in which is non-cyclically polycondensed is contained in an amount of 8.0 wt% within the range specified in the present invention. The total amount of the cyclic amide compound and the non-cyclic amide compound is 8.5 wt%, which is within the range defined by the present invention. Further, glutaric acid is contained as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the balance is tetraethylene glycol monomethyl ether as a solvent within a range specified by the present invention in an amount of 38.5 wt%.

  In Example 13, by including 0.5 wt% of the cyclic amide compound, a sufficient effect on thixotropy was obtained even when 8 wt% of the acyclic amide compound was included. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 14, the addition amount of the cyclic amide compound and the non-cyclic amide compound was changed. In Example 13, acrylic acid-modified rosin was used as the acid-modified rosin within the range specified by the present invention, and 25.0 wt%. In addition, 25.0 wt% of a polymerized rosin is contained within the range defined by the present invention as another rosin. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 8.0 wt%, and sebacic acid and 1,6-hexanediamine are included. The non-cyclic amide compound in which is non-cyclically polycondensed is contained in an amount of 2.0 wt% within the range specified in the present invention. The total amount of the cyclic amide compound and the non-cyclic amide compound is 10.0 wt%, which is within the range defined by the present invention. Further, glutaric acid is included as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the balance is tetraethylene glycol monomethyl ether as a solvent within a range specified by the present invention.

  Even in Example 14, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained. Thus, in Example 14, even if the cyclic amide compound is contained at 8.0 wt%, the thixotropy of the flux, the solder paste printing sag suppressing ability, the printing ability, the heating sag suppressing ability, and the wetting speed are not inhibited. A sufficient effect was obtained for these. Thus, acid-modified rosin, or acid-modified rosin and other rosins, and cyclic amide compounds in which a dicarboxylic acid having 10 carbon atoms and a diamine having 6 carbon atoms are cyclically condensed, and a dicarboxylic acid having 10 carbon atoms And an acyclic amide compound in which a diamine having 6 carbons is acyclic polycondensed within the range specified in the present invention, the thixotropy of the flux, the ability to suppress the printing sag of the solder paste, the printability, and the heating Sufficient effects were obtained on sagging suppression ability and wetting speed.

  In Example 15, the types of the cyclic amide compound and the non-cyclic amide compound were changed. The acid-modified rosin contained 25.0 wt% of acrylic acid-modified rosin within the range defined by the present invention. The polymerized rosin is contained at 25.0 wt% within the range defined by the present invention. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. The thixotropic agent contains 2.0 wt% of a cyclic amide compound obtained by cyclic polycondensation of adipic acid, which is a dicarboxylic acid having 6 carbon atoms, and 1,6-hexanediamine, which is a diamine having 6 carbon atoms, It contains 4.0 wt% of an acyclic amide compound obtained by acyclic polycondensation of adipic acid, which is a dicarboxylic acid having 6 carbon atoms, and 1,6-hexanediamine, which is a diamine having 6 carbon atoms. The total amount of the cyclic amide compound and the acyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. Further, glutaric acid is included as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the remainder as a solvent includes tetraethylene glycol monomethyl ether within a range specified by the present invention as 41.0 wt%.

  Even in Example 15, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained. Thus, in Example 15, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of adipic acid and 1,6-hexanediamine and a non-cyclic polycondensation of adipic acid and 1,6-hexanediamine were prepared. Even if the cyclic amide compound is included within the range specified in the present invention, the thixotropy of the flux, the printing sag suppressing ability of the solder paste, the printing ability, the ability to suppress the heating sag, and the wetting wide speed are not inhibited. A sufficient effect was obtained. Thus, acid-modified rosin, or acid-modified rosin and other rosins, and cyclic amide compounds obtained by cyclic polycondensation of a dicarboxylic acid having 6 carbon atoms and a diamine having 6 carbon atoms, and a dicarboxylic acid having 6 carbon atoms And acyclic amide compounds in which a diamine having 6 carbon atoms is acyclically polycondensed within the range specified by the present invention, the thixotropy of the flux, the ability to suppress the printing sag of the solder paste, the printability, and the heating Sufficient effects were obtained on sagging suppression ability and wetting speed.

  Examples 16 to 18 were obtained by changing the types of other organic acids. In Example 16, acrylic acid-modified rosin was contained as an acid-modified rosin within a range defined by the present invention, and contained 25.0 wt%. As another rosin, 25.0 wt% of a polymerized rosin is included within the range defined by the present invention. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total amount of the cyclic amide compound and the acyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. Further, succinic acid is included as an organic acid within a range specified by the present invention, and 3.0 wt% within the range specified in the present invention, and tetraethylene glycol monomethyl ether as a solvent is included within a range specified by the present invention as 41.0 wt%.

  Also in Example 16, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 17, acrylic acid-modified rosin is contained as an acid-modified rosin within a range specified by the present invention in an amount of 25.0 wt%, and polymerized rosin as another rosin within a range specified by the present invention is 25.0 wt%. % Is included. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total amount of the cyclic amide compound and the acyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. Further, adipic acid is included as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the remainder as a solvent includes tetraethylene glycol monomethyl ether within a range specified by the present invention as 41.0 wt%.

  In Example 17, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 18, the acid-modified rosin contains acrylic acid-modified rosin within a range specified by the present invention in an amount of 25.0 wt%, and other rosin contains a polymerized rosin within a range specified by the present invention of 25.0 wt%. % Is included. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total amount of the cyclic amide compound and the acyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. Further, hydrogenated dimer acid as an organic acid is contained in an amount of 3.0 wt% within the range specified in the present invention, and the remainder is used as a solvent with tetraethylene glycol monomethyl ether in a range specified by the present invention as 41.0 wt%. Including.

  In Example 18, sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 19, an organic acid was added in a composite, and acrylic acid-modified rosin was contained as an acid-modified rosin within a range defined by the present invention in an amount of 25.0 wt%, and polymerized rosin as another rosin. 25.0 wt% is included within the specified range. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total amount of the cyclic amide compound and the acyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. Further, succinic acid as an organic acid, 1.0 wt% within the range defined by the present invention, glutaric acid within the range defined by the present invention, 1.0 wt%, hydrogenated dimer acid, It contains 1.0 wt% within the specified range. The total amount of the two or more organic acids is also within the range defined by the present invention. 41.0 wt% of tetraethylene glycol monomethyl ether is contained within the range defined by the present invention with the balance being the solvent.

  Also in Example 19, sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 20, the addition amount of the organic acid was changed, and acrylic acid-modified rosin was contained as an acid-modified rosin within a range defined by the present invention in an amount of 25.0 wt%, and polymerized rosin was used as another rosin. 25.0 wt% is included within the range specified by the invention. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total amount of the cyclic amide compound and the acyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. Furthermore, glutaric acid is contained as an organic acid within a range specified by the present invention in an amount of 2.0 wt%, and hydrogenated dimer acid is included within a range specified by the present invention in an amount of 8.0 wt%. The total amount of the two or more organic acids is also within the range defined by the present invention. Tetraethylene glycol monomethyl ether containing 34.0 wt% within the range specified in the present invention is used with the balance being the solvent.

  Also in Example 20, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  As shown in Example 16 to Example 20, acid-modified rosin, or acid-modified rosin and other rosins, and cyclic amide compounds and acyclic amide compounds as thixotropic agents are included within the range specified in the present invention. Therefore, changing the type of organic acid within the range specified in the present invention, combining multiple types of organic acids, changing the amount of organic acid, flux thixotropy, solder paste printing droop suppression ability, printing Sufficient effect on the properties, heat sagging suppression ability, and wetting speed were obtained.

  Example 21 was prepared by adding an amine, containing 25.0 wt% of acrylic acid-modified rosin as the acid-modified rosin within the range defined by the present invention, and polymerized rosin as the other rosin. 25.0 wt% in the range. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total amount of the cyclic amide compound and the acyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. Further, glutaric acid is included as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and 2-phenylimidazole is included as an amine within a range specified by the present invention in an amount of 5.0 wt%. Tetraethylene glycol monomethyl ether is contained 36.0 wt% within the range defined by the present invention with the balance being the solvent.

  Also in Example 21, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 22, the type of amine was changed, and acrylic acid-modified rosin was contained as an acid-modified rosin within a range defined by the present invention in an amount of 25.0 wt%, and polymerized rosin as another rosin. 25.0 wt% is included within the specified range. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total amount of the cyclic amide compound and the acyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. Furthermore, glutaric acid is included as an organic acid within a range specified by the present invention at 3.0 wt%, and 2-phenyl-4-methylimidazole is included as an amine within a range specified by the present invention at 5.0 wt%. . Tetraethylene glycol monomethyl ether is contained 36.0 wt% within the range defined by the present invention with the balance being the solvent.

  Also in Example 22, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  As shown in Example 21 to Example 22, acid-modified rosin, or acid-modified rosin and other rosins, and cyclic amide compounds and acyclic amide compounds as thixotropic agents are included within the range specified in the present invention. Therefore, even if the amine is contained within the range specified in the present invention, sufficient effects can be obtained with respect to the thixotropy of the flux, the printing sag suppressing ability of the solder paste, the printing property, the heating sag suppressing ability, and the wetting speed. It was.

  Example 23 was obtained by adding halogen, containing 25.0 wt% of acrylic acid-modified rosin as the acid-modified rosin within the range defined by the present invention, and polymerized rosin as the other rosin. 25.0 wt% in the range. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total amount of the cyclic amide compound and the acyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. Further, glutaric acid is included as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and diphenylguanidine / HBr is included as an amine hydrohalide within a range specified by the present invention. Including. 39.0 wt% of tetraethylene glycol monomethyl ether is contained within the range defined by the present invention with the balance being the solvent.

  Also in Example 23, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 24, the kind of halogen was changed, and acrylic acid-modified rosin was contained as an acid-modified rosin within a range defined by the present invention in an amount of 25.0 wt%, and polymerized rosin as another rosin. 25.0 wt% is included within the specified range. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total amount of the cyclic amide compound and the acyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. Furthermore, glutaric acid is included as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and trans-2,3-dibromo-2-butene-1,4-diol is included as an organic halogen compound in the present invention. Within the specified range, 5.0 wt% is included. Tetraethylene glycol monomethyl ether is contained 36.0 wt% within the range defined by the present invention with the balance being the solvent.

  Also in Example 24, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  As shown in Examples 23 to 24, an acid-modified rosin, or an acid-modified rosin and other rosins, and a cyclic amide compound and an acyclic amide compound as a thixotropic agent are included within the range specified in the present invention. Thus, even if halogen is contained within the range specified in the present invention, sufficient effects can be obtained with respect to flux thixotropy, solder paste printing sag suppression ability, printability, heating sag suppression ability, and wetting speed. It was.

  In Example 25, an antioxidant was added, and acrylic acid-modified rosin was contained as an acid-modified rosin within a range specified by the present invention in an amount of 25.0 wt%, and polymerized rosin as another rosin. 25.0 wt% is included within the specified range. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total amount of the cyclic amide compound and the acyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. Furthermore, glutaric acid is included as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and a hindered phenol antioxidant as an antioxidant is included within a range specified by the present invention at 5.0 wt%. Including. Tetraethylene glycol monomethyl ether is contained 36.0 wt% within the range defined by the present invention with the balance being the solvent.

  Also in Example 25, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  As shown in Example 25, an acid-modified rosin, or an acid-modified rosin and another rosin, and a cyclic amide compound and an acyclic amide compound as a thixotropic agent within the range defined by the present invention Even when the antioxidant is contained within the range specified in the invention, sufficient effects are obtained with respect to the thixotropy of the flux, the ability to suppress the printing sag of the solder paste, the printability, the heating sag suppressing ability, and the wetting speed.

  In Example 26, an amine, a halogen, and an antioxidant were added, and acrylic acid-modified rosin was contained as an acid-modified rosin within a range defined by the present invention, and 25.0 wt%, and polymerized rosin as another rosin. 25.0 wt% is included within the range specified by the present invention. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total amount of the cyclic amide compound and the acyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. Further, succinic acid is included as an organic acid within a range specified by the present invention in an amount of 0.2 wt%, and 2-phenylimidazole is included as an amine within a range specified by the present invention in an amount of 5.0 wt%. In the present invention, diphenylguanidine · HBr is contained in the range specified by the present invention in an amount of 1.0 wt% as a hydrogen salt, and trans-2,3-dibromo-2-butene-1,4-diol is present in the present invention as an organic halogen compound. In the range specified in (1), 3.0 wt% is included, and as the antioxidant, a hindered phenol-based antioxidant is included in the range specified in the present invention (3.0 wt%). 31.8 wt% of tetraethylene glycol monomethyl ether is contained within the range defined by the present invention with the balance being the solvent.

  Also in Example 26, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  As shown in Example 26, an acid-modified rosin, or an acid-modified rosin and another rosin, and a cyclic amide compound and an acyclic amide compound as a thixotropic agent within the range defined by the present invention Even if it contains amine, halogen, and antioxidant within the range specified in the invention, it has sufficient effect on flux thixotropy, solder paste print sag suppression ability, printability, heat sag suppression ability, and wetting speed. Obtained.

  In Examples 27 and 28, the amounts of acid-modified rosin and other rosins were changed. In Example 27, acrylic acid-modified rosin was used as the acid-modified rosin within the range defined by the present invention. It contains 0 wt% and contains 25.0 wt% of polymerized rosin as another rosin within the range defined by the present invention. The total content of the acid-modified rosin and other rosins is 35.0 wt%, which is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total amount of the cyclic amide compound and the acyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. Further, glutaric acid is included as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the balance is tetraethylene glycol monomethyl ether as a solvent within a range specified by the present invention as 56.0 wt%.

  Also in Example 27, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  Example 28 contains 30.0 wt% of acrylic acid-modified rosin as the acid-modified rosin within the range defined by the present invention, and polymerized rosin as the other rosin within the range defined by the present invention of 30.0 wt%. % Is included. The total content of acid-modified rosin and other rosins is 60.0 wt%, which is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total amount of the cyclic amide compound and the acyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. Furthermore, glutaric acid is contained as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the remainder is contained as a solvent and tetraethylene glycol monomethyl ether is contained within a range specified by the present invention at 31.0 wt%.

  Also in Example 28, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Examples 29 to 47, an ester compound was further added as a thixotropic agent. In Example 29, acrylic acid-modified rosin was contained as an acid-modified rosin within a range specified by the present invention in an amount of 25.0 wt%. As another rosin, 25.0 wt% of a polymerized rosin is included within the range defined by the present invention. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, 1.5% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. Of non-cyclic polycondensed acyclic amide compound within a range specified by the present invention in an amount of 2.5 wt%, castor oil as an ester compound as a thixotropic agent, and within a range specified by the present invention 2 0.0wt% is included. The total amount of the cyclic amide compound and the non-cyclic amide compound is 4.0 wt%, which is within the range defined by the present invention. Further, succinic acid is included as an organic acid within a range specified by the present invention, and 3.0 wt% within the range specified in the present invention, and tetraethylene glycol monomethyl ether as a solvent is included within a range specified by the present invention as 41.0 wt%.

  Also in Example 29, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 30, the acid-modified rosin contains acrylic acid-modified rosin within a range specified by the present invention in an amount of 25.0 wt%, and other rosin contains a polymerized rosin within a range specified by the present invention of 25.0 wt%. % Is included. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, 1.5% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. Of non-cyclic polycondensed acyclic amide compound within a range specified by the present invention in an amount of 2.5 wt%, castor oil as an ester compound as a thixotropic agent, and within a range specified by the present invention 2 0.0wt% is included. The total amount of the cyclic amide compound and the non-cyclic amide compound is 4.0 wt%, which is within the range defined by the present invention. Further, adipic acid is included as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the remainder as a solvent includes tetraethylene glycol monomethyl ether within a range specified by the present invention as 41.0 wt%.

  Also in Example 30, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 31, acrylic acid-modified rosin was contained as an acid-modified rosin within a range specified by the present invention in an amount of 25.0 wt%, and polymerized rosin as another rosin within a range specified by the present invention was 25.0 wt%. % Is included. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, 1.5% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. Of non-cyclic polycondensed acyclic amide compound within a range specified by the present invention in an amount of 2.5 wt%, castor oil as an ester compound as a thixotropic agent, and within a range specified by the present invention 2 0.0wt% is included. The total amount of the cyclic amide compound and the non-cyclic amide compound is 4.0 wt%, which is within the range defined by the present invention. Further, hydrogenated dimer acid as an organic acid is contained in an amount of 3.0 wt% within the range specified in the present invention, and the remainder is used as a solvent with tetraethylene glycol monomethyl ether in a range specified by the present invention as 41.0 wt%. Including.

  Also in Example 31, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 32, an organic acid was added in a composite, and acrylic acid-modified rosin was contained as an acid-modified rosin within a range defined by the present invention in an amount of 25.0 wt%, and polymerized rosin as another rosin. 25.0 wt% is included within the specified range. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, 1.5% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. Of non-cyclic polycondensed acyclic amide compound within a range specified by the present invention in an amount of 2.5 wt%, castor oil as an ester compound as a thixotropic agent, and within a range specified by the present invention 2 0.0wt% is included. The total amount of the cyclic amide compound and the non-cyclic amide compound is 4.0 wt%, which is within the range defined by the present invention. Further, succinic acid as an organic acid, 1.0 wt% within the range defined by the present invention, glutaric acid within the range defined by the present invention, 1.0 wt%, hydrogenated dimer acid, It contains 1.0 wt% within the specified range. The total amount of the two or more organic acids is also within the range defined by the present invention. 41.0 wt% of tetraethylene glycol monomethyl ether is contained within the range defined by the present invention with the balance being the solvent.

  Also in Example 32, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 33, the addition amount of the organic acid was changed. The acid-modified rosin contained acrylic acid-modified rosin in an amount of 25.0 wt% within the range defined by the present invention, and the other rosin was polymerized rosin. 25.0 wt% is included within the range specified by the invention. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, 1.5% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. Of non-cyclic polycondensed acyclic amide compound within a range specified by the present invention in an amount of 2.5 wt%, castor oil as an ester compound as a thixotropic agent, and within a range specified by the present invention 2 0.0wt% is included. The total amount of the cyclic amide compound and the non-cyclic amide compound is 4.0 wt%, which is within the range defined by the present invention. Furthermore, glutaric acid is contained as an organic acid within a range specified by the present invention in an amount of 2.0 wt%, and hydrogenated dimer acid is included within a range specified by the present invention in an amount of 8.0 wt%. The total amount of the two or more organic acids is also within the range defined by the present invention. Tetraethylene glycol monomethyl ether containing 34.0 wt% within the range specified in the present invention is used with the balance being the solvent.

  Also in Example 33, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  As shown in Examples 29 to 33, acid-modified rosin, or acid-modified rosin and other rosins, and cyclic amide compounds and acyclic amide compounds as thixotropic agents are included within the range specified in the present invention. Therefore, even if the organic acid is included within the range assumed in the present invention, and the ester compound is further included within the range defined by the present invention as a thixotropic agent, the thixotropy of the flux and the printing sagging of the solder paste are suppressed. A sufficient effect was obtained with respect to performance, printability, ability to suppress heat sag, and wetting speed.

  In Example 34, an amine was added, and acrylic acid-modified rosin was contained as an acid-modified rosin within a range defined by the present invention in an amount of 25.0 wt%. Polymerized rosin was defined as another rosin according to the present invention. 25.0 wt% in the range. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, 1.5% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. Of non-cyclic polycondensed acyclic amide compound within a range specified by the present invention in an amount of 2.5 wt%, castor oil as an ester compound as a thixotropic agent, and within a range specified by the present invention 2 0.0wt% is included. The total amount of the cyclic amide compound and the non-cyclic amide compound is 4.0 wt%, which is within the range defined by the present invention. Further, glutaric acid is included as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and 2-phenylimidazole is included as an amine within a range specified by the present invention in an amount of 5.0 wt%. Tetraethylene glycol monomethyl ether is contained 36.0 wt% within the range defined by the present invention with the balance being the solvent.

  Also in Example 34, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 35, the type of amine was changed, and acrylic acid-modified rosin was contained as an acid-modified rosin within a range defined by the present invention in an amount of 25.0 wt%, and polymerized rosin as another rosin. 25.0 wt% is included within the specified range. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, 1.5% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. Of non-cyclic polycondensed acyclic amide compound within a range specified by the present invention in an amount of 2.5 wt%, castor oil as an ester compound as a thixotropic agent, and within a range specified by the present invention 2 0.0wt% is included. The total amount of the cyclic amide compound and the non-cyclic amide compound is 4.0 wt%, which is within the range defined by the present invention. Furthermore, glutaric acid is included as an organic acid within a range specified by the present invention at 3.0 wt%, and 2-phenyl-4-methylimidazole is included as an amine within a range specified by the present invention at 5.0 wt%. . Tetraethylene glycol monomethyl ether is contained 36.0 wt% within the range defined by the present invention with the balance being the solvent.

  Also in Example 35, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  As shown in Examples 34 to 35, an acid-modified rosin, or an acid-modified rosin and other rosins, and a cyclic amide compound and an acyclic amide compound as a thixotropic agent are included within the range specified in the present invention. Thus, including an amine within the range specified in the present invention, and further including an ester compound as a thixotropic agent within the range specified by the present invention, the thixotropy of the flux, the ability to suppress printing sag of the solder paste, Sufficient effects were obtained for printability, heat sagging suppression ability, and wetting speed.

  Example 36 was obtained by adding halogen, containing 25.0 wt% of acrylic acid-modified rosin as the acid-modified rosin within the range defined by the present invention, and polymerized rosin as the other rosin. 25.0 wt% in the range. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, 1.5% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. Of non-cyclic polycondensed acyclic amide compound within a range specified by the present invention in an amount of 2.5 wt%, castor oil as an ester compound as a thixotropic agent, and within a range specified by the present invention 2 0.0wt% is included. The total amount of the cyclic amide compound and the non-cyclic amide compound is 4.0 wt%, which is within the range defined by the present invention. Further, glutaric acid is included as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and diphenylguanidine / HBr is included as an amine hydrohalide within a range specified by the present invention. Including. 39.0 wt% of tetraethylene glycol monomethyl ether is contained within the range defined by the present invention with the balance being the solvent.

  Also in Example 36, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 37, the halogen type was changed, and acrylic acid-modified rosin was contained as an acid-modified rosin within a range defined by the present invention in an amount of 25.0 wt%, and polymerized rosin as another rosin. 25.0 wt% is included within the specified range. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, 1.5% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. Of non-cyclic polycondensed acyclic amide compound within a range specified by the present invention in an amount of 2.5 wt%, castor oil as an ester compound as a thixotropic agent, and within a range specified by the present invention 2 0.0wt% is included. The total amount of the cyclic amide compound and the non-cyclic amide compound is 4.0 wt%, which is within the range defined by the present invention. Furthermore, glutaric acid is included as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and trans-2,3-dibromo-2-butene-1,4-diol is included as an organic halogen compound in the present invention. Within the specified range, 5.0 wt% is included. Tetraethylene glycol monomethyl ether is contained 36.0 wt% within the range defined by the present invention with the balance being the solvent.

  Also in Example 37, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  As shown in Examples 36 to 37, an acid-modified rosin, or an acid-modified rosin and other rosins, and a cyclic amide compound and an acyclic amide compound as a thixotropic agent are included within the range specified in the present invention. Therefore, including the halogen within the range specified in the present invention, and further including an ester compound as a thixotropic agent within the range specified by the present invention, the thixotropy of the flux, the ability to suppress printing sag of the solder paste, Sufficient effects were obtained for printability, heat sagging suppression ability, and wetting speed.

  In Example 38, an antioxidant was added, and acrylic acid-modified rosin was contained as an acid-modified rosin within a range defined by the present invention in an amount of 25.0 wt%, and polymerized rosin as another rosin. 25.0 wt% is included within the specified range. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, 1.5% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. Of non-cyclic polycondensed acyclic amide compound within a range specified by the present invention in an amount of 2.5 wt%, castor oil as an ester compound as a thixotropic agent, and within a range specified by the present invention 2 0.0wt% is included. The total amount of the cyclic amide compound and the non-cyclic amide compound is 4.0 wt%, which is within the range defined by the present invention. Furthermore, glutaric acid is included as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and a hindered phenol antioxidant as an antioxidant is included within a range specified by the present invention at 5.0 wt%. Including. Tetraethylene glycol monomethyl ether is contained 36.0 wt% within the range defined by the present invention with the balance being the solvent.

  Also in Example 38, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  As shown in Example 38, an acid-modified rosin, or an acid-modified rosin and other rosins, and a cyclic amide compound and an acyclic amide compound as thixotropic agents within the scope defined by the present invention Even if it contains an antioxidant within the range specified by the invention and further contains an ester compound as a thixotropic agent within the range specified by the present invention, the thixotropy of the flux, the ability to suppress the printing sag of the solder paste, and the printability Sufficient effects were obtained with respect to the heat sag suppressing ability and the wetting speed.

  In Example 39, an amine, a halogen, and an antioxidant were added. As the acid-modified rosin, acrylic acid-modified rosin was contained within the range specified by the present invention in an amount of 25.0 wt%, and polymerized rosin was contained as another rosin. 25.0 wt% is included within the range specified by the present invention. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, 1.5% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. Of non-cyclic polycondensed acyclic amide compound within a range specified by the present invention in an amount of 2.5 wt%, castor oil as an ester compound as a thixotropic agent, and within a range specified by the present invention 2 0.0wt% is included. The total amount of the cyclic amide compound and the non-cyclic amide compound is 4.0 wt%, which is within the range defined by the present invention. Further, succinic acid is included as an organic acid within a range specified by the present invention in an amount of 0.2 wt%, and 2-phenylimidazole is included as an amine within a range specified by the present invention in an amount of 5.0 wt%. In the present invention, diphenylguanidine · HBr is contained in the range specified by the present invention in an amount of 1.0 wt% as a hydrogen salt, and trans-2,3-dibromo-2-butene-1,4-diol is present in the present invention as an organic halogen compound. In the range specified in (1), 3.0 wt% is included, and as the antioxidant, a hindered phenol-based antioxidant is included in the range specified in the present invention (3.0 wt%). 31.8 wt% of tetraethylene glycol monomethyl ether is contained within the range defined by the present invention with the balance being the solvent.

  Also in Example 39, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  As shown in Example 39, acid-modified rosin, or acid-modified rosin and other rosins, and cyclic amide compounds and acyclic amide compounds as thixotropic agents within the scope defined by the present invention Including the amine, halogen, and antioxidant within the range specified in the invention, and further including an ester compound as a thixotropic agent within the range specified in the present invention, the thixotropy of the flux and the suppression of the printing sag of the solder paste A sufficient effect was obtained with respect to performance, printability, ability to suppress heat sag, and wetting speed.

  In Examples 40 and 41, the amounts of acid-modified rosin and other rosins were changed. In Example 40, acrylic acid-modified rosin was used as the acid-modified rosin within the range defined by the present invention. It contains 0 wt% and contains 25.0 wt% of polymerized rosin as another rosin within the range defined by the present invention. The total content of the acid-modified rosin and other rosins is 35.0 wt%, which is within the range defined by the present invention. Further, as a thixotropic agent, 1.5% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. Of non-cyclic polycondensed acyclic amide compound within a range specified by the present invention in an amount of 2.5 wt%, castor oil as an ester compound as a thixotropic agent, and within a range specified by the present invention 2 0.0wt% is included. The total amount of the cyclic amide compound and the non-cyclic amide compound is 4.0 wt%, which is within the range defined by the present invention. Further, glutaric acid is included as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the balance is tetraethylene glycol monomethyl ether as a solvent within a range specified by the present invention as 56.0 wt%.

  Also in Example 40, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  Example 41 contains 30.0 wt% of acrylic acid-modified rosin as the acid-modified rosin within the range defined by the present invention, and polymerized rosin as the other rosin within the range defined by the present invention of 30.0 wt. % Is included. The total content of acid-modified rosin and other rosins is 60.0 wt%, which is within the range defined by the present invention. Further, as a thixotropic agent, 1.5% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. Of non-cyclic polycondensed acyclic amide compound within a range specified by the present invention in an amount of 2.5 wt%, castor oil as an ester compound as a thixotropic agent, and within a range specified by the present invention 2 0.0wt% is included. The total amount of the cyclic amide compound and the non-cyclic amide compound is 4.0 wt%, which is within the range defined by the present invention. Furthermore, glutaric acid is contained as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the remainder is contained as a solvent and tetraethylene glycol monomethyl ether is contained within a range specified by the present invention at 31.0 wt%.

  Also in Example 41, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 42, the acid-modified rosin contains acrylic acid-modified rosin within a range specified by the present invention in an amount of 25.0 wt%, and other rosin contains a polymerized rosin within a range specified by the present invention of 25.0 wt%. % Is included. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. Is a non-cyclic polycondensed acyclic amide compound within a range specified by the present invention in an amount of 4.0 wt%, and castor oil as an ester compound as a thixotropic agent is 0% within the range specified by the present invention. .5 wt% included. The total amount of the cyclic amide compound and the acyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. Furthermore, glutaric acid is contained as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the balance is tetraethylene glycol monomethyl ether as a solvent within a range specified by the present invention in an amount of 40.5 wt%.

  Also in Example 42, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 43, the acid-modified rosin contains 25.0 wt% of acrylic acid-modified rosin within the range defined by the present invention, and the polymerized rosin as another rosin within the range defined by the present invention 25.0 wt%. % Is included. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as the thixotropic agent, 0.5% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. Is a non-cyclic polycondensed acyclic amide compound within a range specified by the present invention in an amount of 1.0 wt%, and castor oil as an ester compound as a thixotropic agent is added within the range specified by the present invention. 0.0wt% is included. The total amount of the cyclic amide compound and the non-cyclic amide compound is 1.5 wt%, which is within the range defined by the present invention. Further, glutaric acid is contained as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the remainder as a solvent contains tetraethylene glycol monomethyl ether within a range specified by the present invention as 41.5 wt%.

  Also in Example 43, the thixo ratio was 0.30 or more and less than 0.60, and a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 44, acrylic acid-modified rosin was contained as an acid-modified rosin within a range specified by the present invention in an amount of 25.0 wt%, and polymerized rosin as another rosin within a range specified by the present invention was 25.0 wt%. % Is included. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, 1.5% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. Is a non-cyclic polycondensed acyclic amide compound within the range specified by the present invention in an amount of 0.5 wt%, and castor oil as an ester compound as a thixotropic agent is added within the range specified by the present invention. 0.0wt% is included. The total amount of the cyclic amide compound and the non-cyclic amide compound is 2.0 wt%, which is within the range defined by the present invention. Further, glutaric acid is included as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the remainder as a solvent includes tetraethylene glycol monomethyl ether within a range specified by the present invention as 41.0 wt%.

  Also in Example 44, the thixo ratio was 0.30 or more and less than 0.60, and a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 45, the acid-modified rosin contains acrylic acid-modified rosin within a range specified by the present invention in an amount of 25.0 wt%, and other rosin contains a polymerized rosin within a range specified by the present invention of 25.0 wt%. % Is included. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as the thixotropic agent, 0.5% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. Is a non-cyclic polycondensed acyclic amide compound within a range specified by the present invention in an amount of 1.5 wt%, and castor oil as an ester compound as a thixotropic agent is added within a range specified by the present invention. 0.0wt% is included. The total amount of the cyclic amide compound and the non-cyclic amide compound is 2.0 wt%, which is within the range defined by the present invention. Further, glutaric acid is included as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the remainder as a solvent includes tetraethylene glycol monomethyl ether within a range specified by the present invention as 41.0 wt%.

  Also in Example 45, the thixo ratio was 0.30 or more and less than 0.60, and a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 46, acrylic acid-modified rosin was contained as an acid-modified rosin within a range specified by the present invention in an amount of 25.0 wt%, and polymerized rosin as another rosin within a range specified by the present invention was 25.0 wt%. % Is included. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, 0.1% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. Of non-cyclic polycondensed non-cyclic amide compound within the range specified in the present invention, 2.5 wt%, castor oil as an ester compound as a thixotropic agent, 4 within the range specified in the present invention. 0.0wt% is included. The total amount of the cyclic amide compound and the non-cyclic amide compound is 2.6 wt%, which is within the range defined by the present invention. Further, glutaric acid is contained as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the balance is tetraethylene glycol monomethyl ether as a solvent within a range specified by the present invention in an amount of 40.4 wt%.

  Also in Example 46, the thixo ratio was 0.30 or more and less than 0.60, and a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 47, the acid-modified rosin contains acrylic acid-modified rosin within a range specified by the present invention in an amount of 25.0 wt%, and other rosin contains a polymerized rosin within a range specified by the present invention of 25.0 wt%. % Is included. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, it contains 0.3 wt% of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine within the range defined by the present invention, and contains sebacic acid and 1,6-hexanediamine. Of non-cyclic polycondensed acyclic amide compound within a range specified by the present invention in an amount of 2.5 wt%, castor oil as an ester compound as a thixotropic agent, within a range specified by the present invention. 0.0wt% is included. The total amount of the cyclic amide compound and the non-cyclic amide compound is 2.8 wt%, which is within the range defined by the present invention. Further, glutaric acid is included as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the balance is tetraethylene glycol monomethyl ether as a solvent within a range specified by the present invention.

  Also in Example 47, the thixo ratio was 0.30 or more and less than 0.60, and a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  In Example 48, the addition amount of the cyclic amide compound and the non-cyclic amide compound was changed. As the acid-modified rosin, acrylic acid-modified rosin was contained at 25.0 wt% within the range defined by the present invention. As a polymerized rosin, 25.0 wt% is contained within the range specified in the present invention. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, it contains 0.3 wt% of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine within the range defined by the present invention, and contains sebacic acid and 1,6-hexanediamine. The non-cyclic amide compound in which is non-cyclically polycondensed is contained in an amount of 8.0 wt% within the range specified in the present invention. The total amount of the cyclic amide compound and the non-cyclic amide compound is 8.3 wt%, which is within the range defined by the present invention. Further, glutaric acid is contained as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the balance is tetraethylene glycol monomethyl ether as a solvent within a range specified by the present invention.

  Also in Example 48, a sufficient effect on thixotropy was obtained. Moreover, with the solder paste using this flux, a sufficient effect was obtained with respect to the ability to suppress the sagging of the solder paste. Furthermore, a sufficient effect on printability was obtained. In addition, a sufficient effect on the ability to suppress heating sag was obtained. Furthermore, a sufficient effect on the wetting rate was obtained.

  On the other hand, Comparative Example 1 contains acrylic acid-modified rosin as acid-modified rosin within a range specified by the present invention at 25.0 wt%, and polymerized rosin as other rosin within the range specified by the present invention. 25.0 wt%. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, 0.1% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. The non-cyclic amide compound in which is non-cyclically polycondensed is contained in an amount of 0.1 wt% outside the range specified in the present invention. The total amount of the cyclic amide compound and the acyclic amide compound is 0.2 wt%, which is outside the range specified in the present invention. Further, glutaric acid is contained as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the remainder is contained as a solvent, and tetraethylene glycol monomethyl ether is contained within a range specified by the present invention as 46.8 wt%.

  Even if the content of the cyclic amide compound is within the range specified by the present invention, the content of the acyclic amide compound is less than the range specified by the present invention, and the cyclic amide compound and the non-cyclic amide compound In Comparative Example 1 in which the total amount is less than the range specified in the present invention, no effect was obtained with respect to the thixotropy of the flux, the printing sagging suppression ability of the solder paste, the printing ability, and the heating sagging suppression ability.

  Comparative Example 2 contains acrylic acid-modified rosin as an acid-modified rosin within a range specified by the present invention in an amount of 25.0 wt%, and polymerized rosin as another rosin within a range specified by the present invention in an amount of 25.0 wt. % Is included. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, as a thixotropic agent, 0.1% by weight of a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is included within the range specified by the present invention, and sebacic acid and 1,6-hexanediamine are included. The non-cyclic amide compound obtained by polycondensing non-cyclically is contained in an amount of 0.5 wt% within the range specified in the present invention. However, the total amount of the cyclic amide compound and the non-cyclic amide compound is 0.6 wt%, which is outside the range defined in the present invention. Further, glutaric acid is contained as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the remainder as a solvent contains tetraethylene glycol monomethyl ether within a range specified by the present invention as 46.4 wt%.

  Comparison in which the total amount of the cyclic amide compound and the non-cyclic amide compound is less than the range specified in the present invention even if the content of the cyclic amide compound and the non-cyclic amide compound is within the range specified in the present invention. In Example 2, the effect was not acquired with respect to the thixotropy of a flux, the printing droop suppression capability of a solder paste, printability, and a heating droop suppression capability.

  Comparative Example 3 contains acrylic acid-modified rosin as acid-modified rosin within a range specified by the present invention in an amount of 25.0 wt%, and polymerized rosin as another rosin within a range specified by the present invention in an amount of 25.0 wt. % Is included. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, the thixotropic agent does not contain a cyclic amide compound, but contains 15.0 wt% of an acyclic amide compound in which sebacic acid and 1,6-hexanediamine are polycyclicly condensed outside the range specified in the present invention. Further, glutaric acid as an organic acid is contained in an amount of 3.0 wt% within the range specified in the present invention, and the remainder is contained as a solvent in an amount of 32.0 wt% of tetraethylene glycol monomethyl ether within the range specified in the present invention.

  In Comparative Example 3 that does not contain a cyclic amide compound, the amount of acyclic amide compound added is increased beyond the range specified in the present invention, so that the thixotropy of the flux, the printing sag suppressing ability of the solder paste, and the heating sag suppression are suppressed. The effect was obtained on the performance of the solder paste, but not on the printability of the solder paste.

  Comparative Example 4 contains acrylic acid-modified rosin as an acid-modified rosin within a range specified by the present invention in an amount of 25.0 wt%, and polymerized rosin as another rosin within a range specified by the present invention in an amount of 25.0 wt. % Is included. The total content of acid-modified rosin and other rosins is 50.0 wt%, and is within the range defined by the present invention. Further, the thixotropic agent does not contain a cyclic amide compound or a non-cyclic amide compound, and 5.0% by weight of castor hardened oil as an ester compound is included within the range specified in the present invention. Further, glutaric acid is contained as an organic acid within a range specified by the present invention in an amount of 3.0 wt%, and the balance is tetraethylene glycol monomethyl ether as a solvent within a range specified by the present invention in an amount of 42.0 wt%.

  In Comparative Example 4 which does not contain a cyclic amide compound or a non-cyclic amide compound, by containing an ester compound as a thixotropic agent within the range specified in the present invention, the thixotropy of the flux, the ability to suppress printing sag of the solder paste, Although the effect was obtained with respect to the property, the effect was not obtained with respect to the ability to suppress the heat sag of the solder paste.

  Comparative Example 5 does not contain an acid-modified rosin and contains 50.0 wt% of a polymerized rosin as another rosin within the range defined by the present invention. Further, as a thixotropic agent, a cyclic amide compound obtained by cyclic polycondensation of sebacic acid and 1,6-hexanediamine is contained within a range specified by the present invention in an amount of 2.0 wt%, and sebacic acid and 1,6-hexanediamine are included. In the range specified by the present invention, 4.0 wt% of the non-cyclic amide compound in which is non-cyclically polycondensed is contained. The total amount of the cyclic amide compound and the acyclic amide compound is 6.0 wt%, which is within the range defined by the present invention. 44.0 wt% of tetraethylene glycol monomethyl ether is contained within the range defined by the present invention with the balance being the solvent.

  In Comparative Example 5 containing no acid-modified rosin, no effect was obtained on the wetting rate.

  The thixotropic agent includes cyclic amide compounds and acyclic amide compounds using malonic acid, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, cyclohexanedicarboxylic acid, phthalic acid or terephthalic acid as the dicarboxylic acid. Even in this case, sufficient effects were obtained with respect to the thixotropy of the flux, the ability of the solder paste to suppress printing sag, the printability, and the ability to suppress heat sag.

  In addition, the thixotropic agent contains a cyclic amide compound and a non-cyclic amide compound using cyclohexane tricarboxylic acid, benzene tricarboxylic acid, etc. as tricarboxylic acid, so that the thixotropy of flux, the ability to suppress printing sag of solder paste, printability, heating A sufficient effect was obtained on the ability to suppress sagging.

  Furthermore, thixotropic agents used ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, dimer diamine, phenylenediamine, metaxylylenediamine, paraxylylenediamine, 2,4-diaminotoluene and the like as diamines. Even when the cyclic amide compound and the non-cyclic amide compound were included, sufficient effects were obtained with respect to the thixotropy of the flux, the printing sag suppressing ability of the solder paste, the printing property, and the heating sag suppressing ability.

  Also, thixotropic agents include cyclic amide compounds and acyclic amide compounds that use triaminocyclohexane, trimer triamine, etc. as triamines, so that flux thixotropy, solder paste printing sag suppression ability, printability, heat sag suppression A sufficient effect on the performance was obtained.

  Further, the thixotropic agent contains an acyclic amide compound using acetic acid, palmitic acid, stearic acid, 12-hydroxystearic acid, behenic acid, montanic acid or the like as a monocarboxylic acid. Sufficient effects were obtained for printing sag suppressing ability, printability, and heating sag suppressing ability.

  In addition, thixotropic agents contain acyclic amide compounds that use ammonia, ethylamine, hexylamine, octylamine, stearylamine, etc. as monoamines, so that the thixotropy of flux, the ability to suppress printing sag of solder paste, printability, heating A sufficient effect was obtained on the ability to suppress sagging.

  Furthermore, even if the thixotropic agent contains an acyclic amide compound obtained by ring-opening polymerization of lactam, sufficient effects are obtained with respect to the thixotropy of the flux, the ability to suppress the printing sag of the solder paste, the printing property, and the ability to suppress sag of heating. It was.

<Evaluation of thickening suppression effect of solder paste>
It verified also about the thickening suppression effect of the solder paste prepared using the flux of each Example mentioned above and the solder alloy of the composition shown in the following Table 4.

(1) Verification method About the obtained solder paste, according to the method described in "4.2 Viscosity characteristic test" of JIS Z 3284-3, it was rotated using a rotational viscometer (PCU-205, manufactured by Malcolm Co., Ltd.). The viscosity was continuously measured for 12 hours at a number of 10 rpm and a measurement temperature of 25 ° C. Then, the initial viscosity (viscosity after 30 minutes of stirring) was compared with the viscosity after 12 hours, and the thickening suppression effect was evaluated based on the following criteria.
(2) Criteria ◯: Viscosity after 13 hours ≦ Initial viscosity × 1.2: Small increase in viscosity over time is good x: Viscosity after 13 hours> Initial viscosity × 1.2: Large increase in viscosity over time Bad

  In the solder paste using the solder of the respective examples shown in Table 4 satisfying the fluxes of the respective examples shown in Tables 1 to 3 and the above formulas (1) and (2), the solder paste is printed. In addition to sagging suppression ability, printability, heating sagging suppression ability, and improvement in wetting speed, a sufficient effect was obtained with respect to the thickening suppression effect.

  On the other hand, in the solder paste using the flux of each example shown in Tables 1 to 3 and the solder alloy of each comparative example shown in Table 4 that does not satisfy the above formulas (1) and (2) In addition, an effect was obtained with respect to the printing sag suppressing ability, printability, heating sag suppressing ability, and improvement of the wetting speed of the solder paste, but no effect was obtained with respect to the thickening inhibiting effect.

  From the above, the acid-modified rosin, the thixotropic agent, and the solvent include a thixotropic agent, a dicarboxylic acid and / or a tricarboxylic acid and a diamine and / or a triamine cyclically condensed with a cyclic amide compound, a monocarboxylic acid, It consists of an acyclic amide compound obtained by acyclic polycondensation of dicarboxylic acid and / or tricarboxylic acid and monoamine, diamine and / or triamine, or an acyclic amide compound obtained by ring-opening polymerization of lactam. The carbon number of the tricarboxylic acid is 3 or more and 10 or less, the carbon number of the diamine and the triamine is 2 or more and 54 or less, and the acyclic amide compound is a monoamine, dicarboxylic acid or tricarboxylic acid having 2 or more and 28 or less carbon atoms. , Diamine and triamine have 0 to 54 carbon atoms, cyclic 0.1 wt% to 8.0 wt% of the amide compound, more preferably 0.5 wt% to 1.5 wt% of the cyclic amide compound, 0.5 wt% to 8.0 wt% of the non-cyclic amide compound, and more Preferably, the flux according to the present invention contains 0.5 wt% or more and 4.0 wt% or less of an acyclic amide compound, and the total of the cyclic amide compound and the acyclic amide compound is 1.5 wt% or more and 10.0 wt% or less. Then, compared with the case where a thixotropic agent consists of an acyclic amide compound, thixotropy could be improved and the precipitation of a thixotropic agent could be suppressed, without increasing the content of an acyclic amide compound.

  With the solder paste using this flux, it was possible to obtain good printability in which bleeding, blurring and the like were suppressed, and it was possible to suppress printing sag through which the solder paste after printing flowed. Furthermore, the heating sag of the solder paste due to heating during soldering could be suppressed.

  In addition, by containing 5.0 wt% or more and 50.0 wt% or less of acid-modified rosin, it exhibits a good wetting rate even under conditions of high heat load, enabling stable finishing with any heat history. We were able to provide the flux.

  Further, the flux according to the present invention contains 0 to 50 wt% of rosin other than acid-modified rosin, more preferably 25 to 45 wt% of rosin, and the content of other rosin exceeds 0 wt%. In some cases, even if the total content of acid-modified rosin and other rosins is 60 wt% or less, the thixotropic agent contains a cyclic amide compound and a non-cyclic amide compound, thereby reducing the thixotropy of the flux and preventing the solder paste from printing Performance, printability, ability to suppress heat sag, and improvement in wetting rate due to the inclusion of acid-modified rosin were not hindered, and sufficient effects were obtained.

  In addition, the flux according to the present invention includes an ester compound as a thixotropic agent in an amount of 0 wt% to 8.0 wt%, more preferably an ester compound of 0 wt% to 4.0 wt%, an organic acid of 0 wt% to 10 wt%, More preferably, the organic acid is 0.2 wt% to 5 wt%, the amine is 0 wt% to 20.0 wt%, more preferably the amine is 0 wt% to 5.0 wt%, and the organic halogen compound is 0 wt% to 5 wt%. 0.0 wt% or less, an amine hydrohalide salt is contained in an amount of 0 wt% or more and 2.0 wt% or less, an antioxidant is contained in an amount of 0 wt% or more and 5.0 wt% or less, and the balance is a solvent. With such a composition, the thixotropic agent contains a cyclic amide compound and a non-cyclic amide compound, so that the flux thixotropy, solder paste printing sag suppression ability, printability, heating sag suppression ability, and acid-modified rosin The improvement of the wetting rate due to inclusion was not hindered, and sufficient effects were obtained for these.

  Furthermore, with this flux, As: 25 mass ppm or more and 300 mass ppm or less, Sb: more than 0 mass ppm or more and 3000 mass ppm or less, Bi: more than 0 mass ppm or more and 10,000 mass ppm or less, and Pb: more than 0 mass ppm or more than 5100 mass ppm. At least one of the following, and Ag: 0% by mass to 4% by mass, Cu: 0% by mass to 0.9% by mass, and the balance is Sn, and the above formula (1) and formula (2 ) Solder paste using a solder alloy that satisfies the formula, the thixotropic agent contains a cyclic amide compound and a non-cyclic amide compound, the flux thixotropy, solder paste printing sag suppression, printability, heating sag suppression, The improvement of the wetting rate due to the inclusion of the acid-modified rosin was not hindered, and a sufficient effect was obtained with respect to the effect of suppressing the thickening.

Claims (14)

Contains acid-modified rosin, thixotropic agent, solvent,
5.0 wt% or more and 50.0 wt% or less of acid-modified rosin,
Containing 0 wt% or more and 50 wt% or less of rosin other than acid-modified rosin,
The total content of acid-modified rosin and other rosin is 35 wt% or more and 60 wt% or less,
The thixotropic agent is composed of a cyclic amide compound and an acyclic amide compound, contains the cyclic amide compound in an amount of 0.1 wt% to 8.0 wt%, the acyclic amide compound in an amount of 0.5 wt% to 8.0 wt%, and The total of the cyclic amide compound and the acyclic amide compound is 1.5 wt% or more and 10.0 wt% or less,
The cyclic amide compound is an amide compound having a molecular weight of 3000 or less obtained by cyclic polycondensation of dicarboxylic acid and / or tricarboxylic acid and diamine and / or triamine.
The flux characterized in that the acyclic amide compound is an amide compound in which a monocarboxylic acid, dicarboxylic acid and / or tricarboxylic acid and monoamine, diamine and / or triamine are condensed non-cyclically. The flux according to claim 1, wherein the cyclic amide compound has 3 or more and 10 or less carbon atoms of dicarboxylic acid and tricarboxylic acid. The flux according to claim 1, wherein the cyclic amide compound has 6 to 10 carbon atoms of dicarboxylic acid and tricarboxylic acid. The flux according to claim 2 or 3, wherein the cyclic amide compound has 2 or more and 54 or less carbon atoms of diamine and triamine. The flux according to claim 2 or 3, wherein the cyclic amide compound has 6 carbon atoms in diamine and triamine. The flux according to claim 1, wherein the cyclic amide compound is an amide compound obtained by cyclic polycondensation of a dicarboxylic acid having 3 to 10 carbon atoms and a diamine having 2 to 54 carbon atoms. The flux according to claim 1, wherein the cyclic amide compound is an amide compound obtained by cyclic polycondensation of a dicarboxylic acid having 6 to 10 carbon atoms and a diamine having 6 carbon atoms. In the cyclic amide compound, the carbon number of the dicarboxylic acid and the tricarboxylic acid is 3 or more and 10 or less, and the carbon number of the diamine and the triamine is 2 or more and 54 or less,
The carbon number of monocarboxylic acid, dicarboxylic acid and tricarboxylic acid is 2 or more and 28 or less, and the number of carbon atoms of monoamine, diamine and triamine is 0 or more and 54 or less. flux. The flux according to any one of claims 1 to 8, wherein the thixotropic agent further contains an ester compound. The flux according to claim 9, wherein the thixotropic agent includes castor oil as an ester compound. The thixotropic agent contains 0.5 wt% or more and 1.5 wt% or less of a cyclic amide compound and 0.5 wt% or more and 4.0 wt% or less of an acyclic amide compound. The flux according to claim 9 or 10, wherein the thixotropic agent contains 0 wt% or more and 8.0 wt% or less of an ester compound. Furthermore, 0 wt% or more and 10 wt% or less of organic acid,
0 wt% or more and 20 wt% of amine,
Organohalogen compounds in an amount of 0 wt% to 5 wt%
0 to 2 wt% of amine hydrohalide,
The flux according to any one of claims 1 to 12, comprising an antioxidant in an amount of 0 wt% to 5 wt% . The flux according to any one of claims 1 to 13 and metal powder.
Solder paste characterized by that.

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