Flux and solder paste

Abstract

Provided is flux that can achieve a low residue so as to make it possible to ensure solder wettability, ensure holding properties of a solder ball, and suppress the amount of residue after soldering and enable application for use without washing. The flux includes 1-15% by weight of an organic acid mixture comprising an organic acid with 10 or more carbon atoms, 50-90% by weight of isobornyl cyclohexanol, and 5-45% by weight of a different solvent. The proportion of the isobornyl cyclohexanol is 50-95% by weight, where 100% by weight is the total of the isobornyl cyclohexanol and the different solvent. The organic acid mixture comprising the organic acid with 10 or more carbon atoms comprises 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyldecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid.

Claims

1. A flux comprising: 1 wt % or more and 15 wt % or less of an organic acid mixture including an organic acid with 10 or more carbon atoms; 50 wt % or more and 90 wt % or less of isobornyl cyclohexanol; and 5 wt % or more and 45 wt % or less of a different solvent, the flux being free of a thermosetting resin, wherein, when a total amount of the isobornyl cyclohexanol and the different solvent is 100 wt %, a ratio of the isobornyl cyclohexanol is 50 wt % or more and 95 wt % or less, and wherein the organic acid mixture including an organic acid with 10 or more carbon atoms includes 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid.

2. The flux according to claim 1, further comprising: 0 wt % or more and 15 wt % or less of an organic acid with less than 12 carbon atoms; 0 wt % or more and 5 wt % or less of an amine; 0 wt % or more and 1 wt % or less of an amine hydrohalide; and 0 wt % or more and 5 wt % or less of an organohalogen compound.

3. The flux according to claim 1, wherein the organic acid mixture including an organic acid with 10 or more carbon atoms comprises 30 wt % or more and 60 wt % or less of 2-methylnonanedioic acid, 8 wt % or more and 20 wt % or less of 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 8 wt % or more and 20 wt % or less of 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 15 wt % or more and 30 wt % or less of 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid, when a total amount of the organic acid mixture is 100 wt %.

4. The flux according to claim 3, further comprising: 0 wt % or more and 15 wt % or less of an organic acid with less than 12 carbon atoms; 0 wt % or more and 5 wt % or less of an amine; 0 wt % or more and 1 wt % or less of an amine hydrohalide; and 0 wt % or more and 5 wt % or less of an organohalogen compound.

5. A solder paste, comprising: solder powder; and the flux according to claim 1.

6. The solder paste according to claim 5, wherein the flux further comprises: 0 wt % or more and 15 wt % or less of an organic acid with less than 12 carbon atoms; 0 wt % or more and 5 wt % or less of an amine; 0 wt % or more and 1 wt % or less of an amine hydrohalide; and 0 wt % or more and 5 wt % or less of an organohalogen compound.

7. The solder paste according to claim 5, wherein the organic acid mixture including an organic acid with 10 or more carbon atoms comprises 30 wt % or more and 60 wt % or less of 2-methylnonanedioic acid, 8 wt % or more and 20 wt % or less of 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 8 wt % or more and 20 wt % or less of 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 15 wt % or more and 30 wt % or less of 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid, when a total amount of the organic acid mixture is 100 wt %.

8. The solder paste according to claim 7, wherein the flux further comprises: 0 wt % or more and 15 wt % or less of an organic acid with less than 12 carbon atoms; 0 wt % or more and 5 wt % or less of an amine; 0 wt % or more and 1 wt % or less of an amine hydrohalide; and 0 wt % or more and 5 wt % or less of an organohalogen compound.

Description

EXECUTED EXAMPLES

(1) Fluxes of Executed Examples and Comparison Examples were prepared with the compositions shown in Tables 1 and 2 below to verify the solder wet spreadability, the solder ball retention, and the residue amount. The composition rates in Tables 1 and 2 are expressed in wt (weight) % when the total amount of flux is 100, excluding the ratio of isobornyl cyclohexanol.

(2) <Evaluation of Solder Wet Spreadability>

(3) (1) Verification Method

(4) Each of the fluxes of the Examples and the Comparative Examples was printed on a Cu plate with a diameter φ of 0.34 mm and a thickness t=0.2 mm. Then, solder balls made of solder containing 3 wt % of Ag, 0.5 wt % of Cu, and the balance Sn (Sn-3Ag-0.5Cu) were mounted. The solder balls each have a diameter φ of 0.3 mm. The number of targets to be evaluated is 50 in each Example and each Comparative Example. The test objects made as described above were heated up to from 25° C. to 250° C. in a N.sub.2 atmosphere at a temperature rising rate of 5° C./sec using a reflow furnace. Then, the wet spreading diameter of the molten solder was measured.

(5) (2) Criterion for Determination

(6) ∘: The wet spreading diameter was 350 μm or more.

(7) x: The wet spreading diameter was less than 350 μm.

(8) <Evaluation of Solder Ball Retention>

(9) (1) Verification Method

(10) Flux printing of each Example and each Comparative Example was performed on a Cu electrode of φ 0.24 mm SRO (solder resist opening diameter) at a thickness t=0.2 mm, and Sn-3Ag-0.5Cu solder balls of φ 0.3 mm were mounted thereon, and then it was confirmed whether the balls were retained.

(11) (2) Criterion for Determination

(12) ∘: The solder balls were retained at the mounting position at room temperature and retained on the electrode portion.

(13) x: The solder balls were not retained at the mounting position at room temperature and flowed outside the electrodes.

(14) <Evaluation of Residue Amount>

(15) (1) Verification Method

(16) As a test evaluation method by the TG method (thermogravimetry), an aluminum pan was filled with 10 mg of each of the fluxes of Examples and Comparative Examples, and TGD9600 manufactured by ULVAC was used for heating up to from 25° C. to 250° C. in a N.sub.2 atmosphere at a temperature rising rate of 1° C./sec. It was measured whether the weight of each of the fluxes after heating arrived at 15% or less of the weight before heating.

(17) (2) Criterion for Determination

(18) ∘: The weight was 15% or less of the weight before heating.

(19) x: The weight was greater than 15% of the weight before heating.

(20) The flux whose weight after heating is 15% or less of the weight before heating can be said to be a flux that does not require washing after reflow because the components in the flux are sufficiently volatilized by heating. It can be said that, in the flux whose weight was greater than 15% of the weight before heating, the components in the flux were insufficiently volatilized. If the components in the flux are insufficiently volatilized, resulting in a large amount of residues, it may cause poor conductivity due to moisture absorption or the like.

(21) <Comprehensive Evaluation>

(22) ∘: All of the wet spreading evaluation, the solder ball retention property evaluation, and the residue amount evaluation were 0.

(23) x: Any or all of the wet spreading evaluation, the solder ball retention property evaluation, and the residue amount evaluation was/were x.

(24) TABLE-US-00001 TABLE 1 Ex Ex- Ex- Ex- Ex- Ex Ex- Number ecuted ecuted ecuted ecuted ecuted ecuted ecuted of Ex- Ex- Ex- Ex Ex- Ex- Ex- carbon ample ample ample ample ample ample ample Material atoms 1 2 3 4 5 6 7 Oganic Hardly Organic acid mixture — 5 5 5 15 10 3 1 acid volatile Dodecanedioic acid 12 organic 12-Hydroxystearic acid 18 acid Dimer acid 36 Hydrogenated dimer 36 acid Trimer acid 54 Hydrogenated trimer 54 acid Volatile Glycolic acid 4 organic acid Glutaric acid 5 Rosin Polymerized rosin — Epoxy resin Bisphenol A epoxy resin — Amine 2-Phenylimidozole — 5 1 2-Ethylaminoethanol — Halogen Amine Diphenylguanidine-HBr — hydrohalide Organohalogen Trans-2,3-dibromo-2- — compound butene-1,4-diol Solvent Isobornyl Isobomylcyclohexnol — 75 90 50 65 65 77 78 cyclohexanol Different solvent 1,3-Butylen glycol — 20 5 45 20 20 20 20 Solvent ratio Ratio of isobornyl — 78.9% 94.7% 52.6% 76.5% 76.5% 79.4% 79.6% cyclohexal in all solvents Solder wet spreadability ∘ ∘ ∘ ∘ ∘ ∘ ∘ Solder ball retention ∘ ∘ ∘ ∘ ∘ ∘ ∘ Low residue ∘ ∘ ∘ ∘ ∘ ∘ ∘ Comprehensive evaluation ∘ ∘ ∘ ∘ ∘ ∘ ∘ Ex- Ex- Ex- Ex- Ex- Ex- Ex- Number ecuted ecuted ecuted ecuted ecuted ecuted ecuted of Ex- Ex- Ex- Ex- Ex- Ex- Ex- carbon ample ample ample ample ample ample ample Material atoms 8 9 10 11 12 13 14 Oganic Hardly Organic acid mixture — 1 1 1 5 5 5 acid volatile Dodecanedioic acid 12 5 organic 12-Hydroxystearic acid 18 acid Dimer acid 36 Hydrogenated dimer 306 acid Trimer acid 54 Hydrogenated trimer 54 acid Volatile Glycolic acid 4 1 1 organic acid Glutaric acid 5 1 Rosin Polymerized rosin — Epoxy resin Bisphenol A epoxy resin — Amine 2-Phenylimidozole — 1 1 1 0.5 5 2-Ethylaminoethanol — 5 Halogen Amine Diphenylguanidine-HBr — 1 hydrohalide Organohalogen Trans-2,3-dibromo-2- — 5 compound butene-1,4-diol Solvent Isonornyl Isobornyl cyclohexanol — 76 72 77 74.5 70 70 75 cylohexanol Different solvent 1,3-Butylene glycol — 20 20 20 20 20 20 20 Solvent ratio Ratio of isobornyl — 79.2% 78.3% 79.4% 78.8% 77.8% 77.8% 78.9% cyclohexanol in all solvents Solder wet spreadability ∘ ∘ ∘ ∘ ∘ ∘ ∘ Solder ball retention ∘ ∘ ∘ ∘ ∘ ∘ ∘ Low residue ∘ ∘ ∘ ∘ ∘ ∘ ∘ Comprehensive evaluation ∘ ∘ ∘ ∘ ∘ ∘ ∘ Number Ex- Ex- Ex- Ex- Ex- ecuted ecuted ecuted ecuted ecuted of Ex- Ex- Ex- Ex- Ex- carbon ample ample ample ample ample Material atoms 15 16 17 18 19 Oganic Hardly Organic acid mixture — acid volatile Dodecanedioic acid 12 organic 12-Hydroxystearic acid 18 5 acid Dimer acid 36 5 Hydrogenated dimer acid 36 5 5 5 Trimerr acid 54 Hydrogenated trimer 54 acid Volatile Glycolic acid 4 organic acid Glutaric acid 5 Rosin Polymerized rosin — Epoxy resin Bisphenol A epoxy resin — Amine 2-Phenylimidozole — 2-Ethylaminoethanol — Halogen Amine Diphenylguanidine-HBr — hydrohalide Organohalogen Trans-2,3-dibromo-2- — compound butene-1,4-diol Solvent Isobomyl Isobomyl — 75 75 75 90 50 cyclohexanol cyclohexanol Different solvent 1,3-Butylene glycol — 20 20 20 5 45 Solvent ratio Ratio of isobornyl — 78.9% 78.9% 78.9% 94.7% 52.6% cyclohexanol in all solvents Solder wet spreadability ∘ ∘ ∘ ∘ ∘ Solder ball retention ∘ ∘ ∘ ∘ ∘ Low residue ∘ ∘ ∘ ∘ ∘ Comprehensive evaluation ∘ ∘ ∘ ∘ ∘

(25) TABLE-US-00002 TABLE 2 Number Executed Executed Executed Executed Executed Executed of carbon Example Example Example Example Example Example Material atoms 20 21 22 23 24 25 Oganic Hardly Organic acid mixture — acid volatile Dodecanedioic acid 12 organic 12-Hydroxystearic acid 18 acid Dimer acid 36 Hydrogenated dimer 36 15 10 3 1 1 1 acid Trimer acid 54 Hydrogenated trimer 54 acid Volatile Glycolic acid 4 1 1 organic acid Glutaric acid 5 Rosin Polymerized rosin — Epoxy resin Bisphenol A epoxy resin — Amine 2-Phenylimidozole — 5 1 1 1 2-Ethylaminoethanol — Halogenn Amine Diphenylguanidine-HBr — 1 hydro Organohalogen Trans-2,3-dibromo-2- — 5 compound butene-1,4-diol Solvent Isobornyl Isobornyl — 65 65 77 78 76 72 cyclohexanol cyclohexanol Different solvent 1,3-Butylene glycol — 20 20 20 20 20 20 Solvent ratio Ratio of isobornyl — 76.5% 76.5% 79.4% 79.6% 79.2% 78.3% cyclohex in all solvents Solder wet spreadability ∘ ∘ ∘ ∘ ∘ ∘ Solder ball retention ∘ ∘ ∘ ∘ ∘ ∘ Low residue ∘ ∘ ∘ ∘ ∘ ∘ Comprehensive evaluation ∘ ∘ ∘ ∘ ∘ ∘ Number Executed Executed Executed Executed Executed Executed of carbon Example Example Example Example Example Example Material atoms 26 27 28 29 30 31 Oganic Hardly Organic acid mixture — acid volatile Dodecanedioic acid 12 organic 12-Hydroxystearic acid 18 acid Dimer acid 36 Hydrogenated trimer 36 1 5 5 5 acid Trimer acid 54 5 Hydrogenated trimer 54 5 acid Volatile Glycolic acid 4 organic acid Glutaric acid 5 1 Rosin Polymerized rosin — Epoxy resin Bisphenol A epoxy resin — Amine 2-Phenylimidozole — 1 0.5 5 2-Ethylaminoethanol — 5 Halogen Amine Diphenylguanidine-HBr — hydrohalide Organohalogen Trans-2,3-dibromo-2- — compound butene-1,4-diol Solvent Isobornyl Isobornyl — 77 74.5 70 70 75 75 cyclohexanol cyclohexanol Different solvent 1,3-Butylene glycol — 20 20 20 20 20 20 Solvent ratio Ratio of isobornyl — 79.4% 78.8% 77.8% 77.8% 78.9% 78.9% cyclohexanol in all solvents Solder wet spreadability ∘ ∘ ∘ ∘ ∘ ∘ Solder ball retention ∘ ∘ ∘ ∘ ∘ ∘ Low residue ∘ ∘ ∘ ∘ ∘ ∘ Comprehensive evaluation ∘ ∘ ∘ ∘ ∘ ∘ Number Executed Comparison Comparison Comparison of carbon Example Example Example Example Material atoms 32 1 2 3 Oganic Hardly Organic acid mixture — 5 20 acid volatile Dodecanedioic acid 12 organic 12-Hydroxystearic acid 18 acid Dimer acid 36 Hydrogenated dimer 36 acid Timer acid 54 Hydrogenated trimer 54 acid Volatile Glycolic acid 4 15 5 15 organic acid Glutaric acid 5 Rosin Polymerized rosin — Epoxy resin Bisphenol A epoxy resin — Amine 2-Phenylimidozole — 2-Ethylaminoethanol — Halogen Amine Diphenylguanidine-HBr — hydrohalide Organiohalogen Trans-2,3-dibromo-2- — compound butene-1,4-diol Solvent Isobornyl Isoborynl — 60 60 75 65 cyclohexanol cyclohexanol Different solvent 1,3-Butylene glycol — 20 20 20 20 Solvent ratio Ratio of isobornyl — 75.0% 75.0% 78.9% 76.5% cyclohexnol in all solvents Solder wet spreadability ∘ ∘ x x Solder ball retention ∘ ∘ ∘ ∘ Low residue ∘ x ∘ ∘ Comprehensive evaluation ∘ x x x Number Comparison Comparison Comparison of carbon Example Example Example Material atoms 4 5 6 Oganic Hardly Organic acid mixture — 5 5 5 acid volatile Dodecanedioic acid 12 organic 12-Hydroxystearic acid 18 acid Dimer acid 36 Hydrogenated dimer 36 acid Trimer acid 54 Hydrogenated trimer 54 acid Volatile Glycolic acid 4 organic acid Glutaric acid 5 Rosin Polymerized rosin — 35 Epoxy resin Bisphenol A epoxy resin — 35 Amine 2-Phenylimidozole — 2-Ethylaminoethanol — Halogen Amine Diphenylguanidine-HBr — hydrohalide Organohalogen Trans-2,3-dibromo-2- — compound butene-1,4-diol Solvent Isobornyl Isobornyl — 40 40 cyclohexanol cyclohexanol Different solvent 1,3-Butylene glycol — 95 20 20 Solvent ratio Ratio of isobornyl — 0.0% 66.7% 66.7% cyclohexnol in all solvents Solder wet spreadability ∘ ∘ ∘ Solder ball retention x ∘ ∘ Low residue ∘ x x Comprehensive evaluation x x x

(26) As shown in Executed Example 1, the flux containing: an organic acid mixture including 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid as an organic acid mixture including an organic acid with 10 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 75 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 78.9 wt % within the range defined in the present invention, had 350 μm or more of the solder wet spreading diameter which showed good solder wet spreading to provide a sufficient solder wet spreading effect. Further, the viscosity of the flux at ordinary temperature before heating could be increased to such an extent that the solder balls could be retained, and the solder balls could be retained. Furthermore, when the residue amount was 15 wt % or less, and a sufficient effect of suppressing the residue amount to attain low residue was obtained. It was found that, in the evaluation of the solder ball retention, when the test objects of Executed Examples in which the solder balls were retained at the mounting position at room temperature and retained at the electrode portion were each heated up to from 25° C. to 250° C. in a N.sub.2 atmosphere at a temperature rising rate of 5° C./sec using a reflow furnace, the flux was kept at a predetermined viscosity during the temperature rising process, and that the solder balls could be retained during heating.

(27) As shown in Executed Example 2, the flux containing: an organic acid mixture including 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid as an organic acid mixture including an organic acid with 10 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 90 wt %, which was increased within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 5 wt %, which was decreased within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 94.7 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(28) As shown in Executed Example 3, the flux containing: an organic acid mixture including 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid as an organic acid mixture including an organic acid with 10 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 50 wt %, which was decreased within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 45 wt %, which was increased within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 52.6 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(29) As shown in Executed Example 4, the flux containing: an organic acid mixture including 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid as an organic acid mixture including an organic acid with 10 or more carbon atoms in an amount of 15 wt %, which was increased within the range defined in the present invention; isobornyl cyclohexanol in an amount of 65 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 76.5 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(30) As shown in Executed Example 5, the flux containing: an organic acid mixture including 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid as an organic acid mixture including an organic acid with 10 or more carbon atoms in an amount of 10 wt %, which was increased within the range defined in the present invention; further 2-phenylimidazole as an amine in an amount of 5 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 65 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 76.5 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(31) As shown in Executed Example 6, the flux containing: an organic acid mixture including 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid as an organic acid mixture including an organic acid with 10 or more carbon atoms in an amount of 3 wt %, which was decreased within the range defined in the present invention; isobornyl cyclohexanol in an amount of 77 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 79.4 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(32) As shown in Executed Example 7, the flux containing: an organic acid mixture including 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid as an organic acid mixture including an organic acid with 10 or more carbon atoms in an amount of 1 wt %, which was decreased within the range defined in the present invention; further 2-phenylimidazole as an amine in an amount of 1 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 78 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 79.6 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(33) As shown in Executed Example 8, the flux containing: an organic acid mixture including 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid as an organic acid mixture including an organic acid with 10 or more carbon atoms in an amount of 1 wt %, which was decreased within the range defined in the present invention; further glycolic acid with 4 carbon atoms as a different organic acid in an amount of 1 wt % within the range defined in the present invention; 2-phenylimidazole as a amine in an amount of 1 wt % within the range defined in the present invention; an amine hydrohalide as a halogen in an amount of 1 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 76 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 79.2 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(34) As shown in Executed Example 9, the flux containing: an organic acid mixture including 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid as an organic acid mixture including an organic acid with 10 or more carbon atoms in an amount of 1 wt %, which was decreased within the range defined in the present invention; further glycolic acid with 4 carbon atoms as a different organic acid in an amount of 1 wt % within the range defined in the present invention; 2-phenylimidazole as a amine in an amount of 1 wt % within the range defined in the present invention; an organohalogen compound as a halogen in an amount of 5 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 72 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 78.3 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(35) As shown in Executed Example 10, the flux containing: an organic acid mixture including 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid as an organic acid mixture including an organic acid with 10 or more carbon atoms in an amount of 1 wt %, which was decreased within the range defined in the present invention; further glutaric acid with 5 carbon atoms as a different organic acid in an amount of 1 wt % within the range defined in the present invention; 2-phenylimidazole as a amine in an amount of 1 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 77 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 79.4 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(36) As shown in Executed Example 11, the flux containing: an organic acid mixture including 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid as an organic acid mixture including an organic acid with 10 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; further 2-phenylimidazole as an amine in an amount of 0.5 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 74.5 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 78.8 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(37) As shown in Executed Example 12, the flux containing: an organic acid mixture including 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid as an organic acid mixture including an organic acid with 10 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; further 2-phenylimidazole as an amine in an amount of 5 wt %, which was increased within the range defined in the present invention; isobornyl cyclohexanol in an amount of 70 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 77.8 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(38) As shown in Executed Example 13, the flux containing: an organic acid mixture including 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid as an organic acid mixture including an organic acid with 10 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; further 2-ethylaminoethanol as an amine in an amount of 5 wt %, which was increased within the range defined in the present invention; isobornyl cyclohexanol in an amount of 70 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 77.8 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(39) As shown in Executed Example 14, the flux containing: dodecanedioic acid with 12 carbon atoms as an organic acid with 12 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 75 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 78.9 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(40) As shown in Executed Example 15, the flux containing: 12-hydroxystearic acid with 18 carbon atoms as an organic acid with 12 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 75 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 78.9 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(41) As shown in Executed Example 16, the flux containing: a dimer acid with 36 carbon atoms which was a reaction product of oleic acid and linoleic acid as an organic acid with 12 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 75 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 78.9 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(42) As shown in Executed Example 17, the flux containing: a hydrogenated dimer acid obtained by adding hydrogen to (hydrogenating) the dimer acid with 36 carbon atoms which was a reaction product of oleic acid and linoleic acid as an organic acid with 12 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 75 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 78.9 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(43) As shown in Executed Example 18, the flux containing: a hydrogenated dimer acid obtained by adding hydrogen to (hydrogenating) the dimer acid with 36 carbon atoms which was a reaction product of oleic acid and linoleic acid as an organic acid with 12 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 90 wt %, which was increased within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 5 wt %, which was decreased within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 94.7 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(44) As shown in Executed Example 19, the flux containing: a hydrogenated dimer acid obtained by adding hydrogen to (hydrogenating) the dimer acid with 36 carbon atoms which was a reaction product of oleic acid and linoleic acid as an organic acid with 12 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 50 wt %, which was decreased within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 45 wt %, which was increased within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 52.6 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(45) As shown in Executed Example 20, the flux containing: a hydrogenated dimer acid obtained by adding hydrogen to (hydrogenating) the dimer acid with 36 carbon atoms which was a reaction product of oleic acid and linoleic acid as an organic acid with 12 or more carbon atoms in an amount of 15 wt %, which was increased within the range defined in the present invention; isobornyl cyclohexanol in an amount of 65 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 76.5 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(46) As shown in Executed Example 21, the flux containing: a hydrogenated dimer acid obtained by adding hydrogen to (hydrogenating) the dimer acid with 36 carbon atoms which was a reaction product of oleic acid and linoleic acid as an organic acid with 12 or more carbon atoms in an amount of 10 wt %, which was increased within the range defined in the present invention; further 2-phenylimidazole as an amine in an amount of 5 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 65 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 76.5 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(47) As shown in Executed Example 22, the flux containing: a hydrogenated dimer acid obtained by adding hydrogen to (hydrogenating) the dimer acid with 36 carbon atoms which was a reaction product of oleic acid and linoleic acid as an organic acid with 12 or more carbon atoms in an amount of 3 wt %, which was decreased within the range defined in the present invention; isobornyl cyclohexanol in an amount of 77 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 79.4 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(48) As shown in Executed Example 23, the flux containing: a hydrogenated dimer acid obtained by adding hydrogen to (hydrogenating) the dimer acid with 36 carbon atoms which was a reaction product of oleic acid and linoleic acid as an organic acid with 12 or more carbon atoms in an amount of 1 wt %, which was decreased within the range defined in the present invention; further 2-phenylimidazole as an amine in an amount of 1 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 78 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 79.6 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(49) As shown in Executed Example 24, the flux containing: a hydrogenated dimer acid obtained by adding hydrogen to (hydrogenating) the dimer acid with 36 carbon atoms which was a reaction product of oleic acid and linoleic acid as an organic acid with 12 or more carbon atoms in an amount of 1 wt %, which was decreased within the range defined in the present invention; further glycolic acid with 4 carbon atoms as a different organic acid in an amount of 1 wt % within the range defined in the present invention; 2-phenylimidazole as an amine in an amount of 1 wt % within the range defined in the present invention; amine hydrohalide as a halogen in an amount of 1 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 76 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 79.2 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(50) As shown in Executed Example 25, the flux containing: a hydrogenated dimer acid obtained by adding hydrogen to (hydrogenating) the dimer acid with 36 carbon atoms which was a reaction product of oleic acid and linoleic acid as an organic acid with 12 or more carbon atoms in an amount of 1 wt %, which was decreased within the range defined in the present invention; further glycolic acid with 4 carbon atoms as a different organic acid in an amount of 1 wt % within the range defined in the present invention; 2-phenylimidazole as an amine in an amount of 1 wt % within the range defined in the present invention; an organohalogen compound as a halogen in an amount of 5 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 72 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 78.3 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(51) As shown in Executed Example 26, the flux containing: a hydrogenated dimer acid obtained by adding hydrogen to (hydrogenating) the dimer acid with 36 carbon atoms which was a reaction product of oleic acid and linoleic acid as an organic acid with 12 or more carbon atoms in an amount of 1 wt %, which was decreased within the range defined in the present invention; further glutaric acid with 5 carbon atoms as a different organic acid in an amount of 1 wt % within the range defined in the present invention; 2-phenylimidazole as an amine in an amount of 1 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 77 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 79.4 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(52) As shown in Executed Example 27, the flux containing: a hydrogenated dimer acid obtained by adding hydrogen to (hydrogenating) the dimer acid with 36 carbon atoms which was a reaction product of oleic acid and linoleic acid as an organic acid with 12 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; further 2-phenylimidazole as an amine in an amount of 0.5 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 74.5 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 78.8 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(53) As shown in Executed Example 28, the flux containing: a hydrogenated dimer acid obtained by adding hydrogen to (hydrogenating) the dimer acid with 36 carbon atoms which was a reaction product of oleic acid and linoleic acid as an organic acid with 12 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; further 2-phenylimidazole as an amine in an amount of 5 wt %, which was increased within the range defined in the present invention; isobornyl cyclohexanol in an amount of 70 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 77.8 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(54) As shown in Executed Example 29, the flux containing: a hydrogenated dimer acid obtained by adding hydrogen to (hydrogenating) the dimer acid with 36 carbon atoms which was a reaction product of oleic acid and linoleic acid as an organic acid with 12 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; further 2-ethylaminoethanol as an amine in an amount of 5 wt %, which was increased within the range defined in the present invention; isobornyl cyclohexanol in an amount of 70 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 77.8 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(55) As shown in Executed Example 30, the flux containing: a trimer acid with 54 carbon atoms which was a reaction product of oleic acid and linoleic acid as an organic acid with 12 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 75 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 78.9 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(56) As shown in Executed Example 31, the flux containing: a hydrogenated trimer acid obtained by adding hydrogen to (hydrogenating) a trimer acid with 54 carbon atoms which was a reaction product of oleic acid and linoleic acid as an organic acid with 12 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 75 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 78.9 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(57) As shown in Executed Example 32, the flux containing: an organic acid mixture including 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid as an organic acid mixture including an organic acid with 10 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; further glycolic acid with 4 carbon atoms as a different organic acid in an amount of 15 wt %, which was increased within the range defined in the present invention; isobornyl cyclohexanol in an amount of 60 wt % within the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 75.0 wt % within the range defined in the present invention, also provided good solder wet spreading and a sufficient solder wet spreading effect. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, a sufficient effect of suppressing the residue amount to attain low residue was obtained.

(58) Contrary to these, as shown in Comparison Example 1, the flux containing: an organic acid mixture including 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid as an organic acid mixture including an organic acid with 10 or more carbon atoms in an amount of 20 wt %, which fell beyond the range defined in the present invention; isobornyl cyclohexanol in an amount of 60 wt %; and 1,3-butylene glycol as a different solvent in an amount of 20 wt %, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 75 wt % within the range defined in the present invention, provided a solder wet spreading effect and an effect of retaining the solder balls at ordinary temperature before heating. However, the residue amount exceeded 15 wt % and could not be suppressed, so that the low residue effect was not obtained.

(59) As shown in Comparison Example 2, the flux containing: no organic acid mixture including an organic acid with 10 or more carbon atoms; no organic acid with 12 or more carbon atoms; glycolic acid with 4 carbon atoms as an organic acid in an amount of 5 wt % within the range defined in the present invention; isobornyl cyclohexanol in an amount of 75 wt %; and 1,3-butylene glycol as a different solvent in an amount of 20 wt %, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 78.9 wt % within the range defined in the present invention, provided an effect of retaining the solder balls at ordinary temperature before heating and a low residue effect. However, the wet spreading diameter of the solder was less than 350 μm, the solder was not wet spread, and the solder wet spreading effect was not obtained.

(60) As shown in Comparison Example 3, the flux containing: no organic acid mixture including an organic acid with 10 or more carbon atoms; no organic acid with 12 or more carbon atoms; glycolic acid with 4 carbon atoms as an organic acid in an amount of 15 wt %, which was increased within the range defined in the present invention; isobornyl cyclohexanol in an amount of 65 wt %; and 1,3-butylene glycol as a different solvent in an amount of 20 wt %, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 76.5 wt % within the range defined in the present invention, also provided an effect of retaining the solder balls at ordinary temperature before heating and a low residue effect. However, the solder wet spreading effect was not obtained.

(61) As shown in Comparison Example 4, the flux containing: an organic acid mixture including 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid as an organic acid mixture including an organic acid with 10 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; containing no isobornyl cyclohexanol; and 1,3-butylene glycol as solvents in an amount of 95 wt %, which fell beyond the scope defined in the present invention, wherein the ratio of isobornyl cyclohexanol was 0 wt %, which fell below the range defined in the present invention, provided a solder wet spreading effect and a low residue effect. However, the effect of retaining the solder balls at ordinary temperature before heating was not obtained.

(62) As shown in Comparison Example 5, the flux containing: an organic acid mixture including 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid as an organic acid mixture including an organic acid with 10 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; polymerized rosin as rosin, which was not added in the present invention, in an amount of 35 wt %; isobornyl cyclohexanol in an amount of 40 wt %, which fell below the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 66.7 wt % within the range defined in the present invention, provided a solder wet spreading effect and an effect of retaining the solder balls at ordinary temperature before heating. However, the low residue effect was not obtained since the rosin formed residues.

(63) As shown in Comparison Example 6, the flux containing: an organic acid mixture including 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid as an organic acid mixture including an organic acid with 10 or more carbon atoms in an amount of 5 wt % within the range defined in the present invention; an epoxy resin, which was not added in the present invention, in an amount of 35 wt %; isobornyl cyclohexanol in an amount of 40 wt %, which fell below the range defined in the present invention; and 1,3-butylene glycol as a different solvent in an amount of 20 wt % within the range defined in the present invention, wherein, when the total amount of isobornyl cyclohexanol and the different solvent was 100 wt %, the ratio of isobornyl cyclohexanol was 66.7 wt % within the range defined in the present invention, also provided a solder wet spreading effect and an effect of retaining the solder balls at ordinary temperature before heating. However, the low residue effect was not obtained since the epoxy resin formed residues.

(64) In view of the above, the flux containing: 1 wt % or more and 15 wt % or less of an organic acid mixture including an organic acid with 10 or more carbon atoms; 50 wt % or more and 90 wt % or less of isobornyl cyclohexanol; and 5 wt % or more and 45 wt % or less of a different solvent, wherein, when the total amount of the isobornyl cyclohexanol and the different solvent is 100 wt %, the ratio of the isobornyl cyclohexanol is 50 wt % or more and 95 wt % or less, and wherein the organic acid mixture containing an organic acid with 10 or more carbon atoms includes 2-methylnonanedioic acid, 4-(methoxycarbonyl)-2,4-dimethylundecanedioic acid, 4,6-bis(methoxycarbonyl)-2,4,6-trimethyltridecanedioic acid, and 8,9-bis(methoxycarbonyl)-8,9-dimethylhexadecanedioic acid, and the solder paste using the flux can provide good solder wet spreading. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, the residue amount was suppressed.

(65) Further, the flux containing: 1 wt % or more and 15 wt % or less of an organic acid with 12 or more carbon atoms; 50 wt % or more and 90 wt % or less of isobornyl cyclohexanol; and 5 wt % or more and 45 wt % or less of a low different solvent, wherein, when the total amount of the isobornyl cyclohexanol and the different solvent is 100 wt %, the ratio of the isobornyl cyclohexanol is 50 wt % or more and 95 wt % or less, and the solder paste using the flux can provide good solder wet spreading. Also, the solder balls could be retained at ordinary temperature before heating. Furthermore, the residue amount was suppressed.

(66) These effects were not inhibited even by incorporating an organic acid with less than 12 carbon atoms, an amine, an amine hydrohalide, and an organohalogen compound as activators within the ranges defined in the present invention. It was found that, in particular, when an organic acid mixture including an organic acid with 10 or more carbon atoms was contained in an amount of 1 wt % or more and 3 wt % or less, and when an organic acid with 12 or more carbon atoms was contained in an amount of 1 wt % or more and 3 wt % or less, the addition of other activators such as an amine in an amount of 0.5 wt % or more was more preferable. In addition, it was found that, when an organic acid mixture including an organic acid with 10 or more carbon atoms was contained in an amount of more than 3 wt % and 15 wt % or less, and when an organic acid with 12 or more carbon atoms was contained in an amount of more than 3 wt % and 15 wt % or less, sufficient activity was obtained even though no other activator was contained. It was also found that, even in this case, the inclusion of a different activator further increased the activity, and the retention properties of solder balls and the low residue property were not inhibited.