JP2024031830A - Flux composition, solder composition, and electronic substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flux composition which can sufficiently suppress occurrence of a solder ball regardless of a halogen free or non-halogen type.

SOLUTION: A flux composition contains (A) a resin and (B) an activator, wherein the component (B) contains (B1) a compound having a quinoline skeleton.

SELECTED DRAWING: None

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a flux composition, a solder composition, and an electronic board.

A solder composition is a paste-like mixture obtained by kneading solder powder with a flux composition (rosin resin, activator, solvent, etc.) (see Patent Document 1). In recent years, in consideration of environmental issues, there has been a demand for halogen-free solder compositions that contain less halogen, or halogen-free solder compositions that do not contain halogen at all.

Patent No. 5887330

However, when a halogen-free solder composition is used, it becomes difficult to remove the oxide film from the solder powder, resulting in the formation of solder balls.

An object of the present invention is to provide a flux composition, a solder composition, and an electronic board that can sufficiently suppress the generation of solder balls despite being halogen-free or non-halogen type.

According to the present invention, the following flux composition, solder composition, and electronic board are provided.
[1] Contains (A) a resin and (B) an activator,
The component (B) contains (B1) a compound having a quinoline skeleton.
Flux composition.
[2] In the flux composition according to [1],
The component (B1) is a compound represented by the following general formula (1),
Flux composition.

(In general formula (1), X ¹ to X ⁷ are independently hydrogen, a hydroxyl group, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having ¹ to ³ carbon atoms; or two may form a ring.)

[3] In the flux composition according to [1] or [2],
The component (B) further contains (B2) an azole,
Flux composition.
[4] In the flux composition according to any one of [1] to [3],
The component (B) further contains (B3) an organic acid.
Flux composition.
[5] In the flux composition according to any one of [1] to [4],
further containing (C) a thixotropic agent;
Flux composition.
[6] Containing the flux composition according to any one of [1] to [5] and (D) solder powder,
Solder composition.
[7] In the solder composition according to [6],
The alloy system of the component (D) is Sn-Bi system, Sn-Ag-Bi system, Sn-Ag-Sb-Bi system, Sn-Bi-Sb-In system, Sn-Bi-Sb-In-Ni- Co-based and Sn-Bi-Sb-Cu-In-Ni-Co based,
Solder composition.
[8] In the solder composition according to [6] or [7],
The alloy composition of the component (D) is Sn-57Bi-1Ag, Sn-58Bi, Sn-35Bi-1Ag, Sn-45Bi-1.5Sb-0.5Ag, Sn-50Bi-1Sb-0.5In, Sn- 50Bi-1Sb-0.5In-0.05Ni-0.1Co, and Sn-50Bi-1Sb-2Cu-0.5In-0.05Ni-0.1Co,
Solder composition.
[9] A soldered portion using the solder composition according to any one of [6] to [8],
Electronic substrate.

According to one aspect of the present invention, it is possible to provide a flux composition, a solder composition, and an electronic board that can sufficiently suppress the generation of solder balls despite being halogen-free or non-halogen type.

[Flux composition]
First, the flux composition according to this embodiment will be explained. The flux composition according to the present embodiment is a component other than the solder powder in the solder composition, and contains (A) a resin and (B) an activator, which will be described below. Further, the component (B) contains (B1) a compound having a quinoline skeleton.

The reason why the flux composition according to this embodiment is able to sufficiently suppress the generation of solder balls despite being halogen-free or non-halogen type is not necessarily clear, but the inventors of the present invention speculate as follows. .
That is, among solder alloys, in solder alloys such as Sn--Bi, since Bi is easily oxidized, it is difficult to remove an oxide film from the solder powder, and it is also difficult to suppress re-oxidation. Therefore, conventionally, a halogen-based activator has been blended into a flux composition in addition to an organic acid and an amine-based activator. This promoted the removal of the oxide film and suppressed re-oxidation, thereby suppressing the generation of solder balls. In addition, when a halogen-based activator is not used, it is not possible to remove the Bi oxide film or suppress reoxidation, but with (B1) a compound having a quinoline skeleton, it is possible to remove the Bi oxide film and suppress reoxidation. Although the reason for this is not necessarily clear, the present inventors assume that component (B1) forms a chelate on the metal surface after removing the solder oxide film, thereby achieving the effect of suppressing re-oxidation. Component (B1) also has the advantage that it has less adverse effect on the stability and reliability of the solder composition than organic acids and other amine-based activators. The present inventors conjecture that the effects of the present invention described above are achieved in the manner described above.

[(A) Component]
Examples of the resin (A) used in this embodiment include rosin resins, acrylic resins, epoxy resins, and phenol resins. These may be used alone or in combination of two or more. Among these, rosin resins or acrylic resins are preferred from the viewpoint of viscosity stability.
Examples of rosin-based resins include rosins and rosin-based modified resins. Examples of rosins include gum rosin, wood rosin, and tall oil rosin. Examples of the rosin-based modified resin include disproportionated rosin, polymerized rosin, hydrogenated rosin, and derivatives thereof. Hydrogenated rosins include fully hydrogenated rosins, partially hydrogenated rosins, unsaturated organic acids (alpha, β-, aliphatic unsaturated monobasic acids such as (meth)acrylic acid, fumaric acid, maleic acid, etc.) Unsaturated organic acid-modified rosin, which is a modified rosin of aliphatic unsaturated dibasic acids such as unsaturated carboxylic acids, unsaturated carboxylic acids with an aromatic ring such as cinnamic acid, etc.) (also called rosin). These rosin resins may be used alone or in combination of two or more. Moreover, among these rosin-based resins, it is preferable to use fully hydrogenated rosin and hydrogenated acid-modified rosin, and it is more preferable to use fully hydrogenated rosin and hydrogenated acid-modified rosin together.
Acrylic resins include acrylic acid, methacrylic acid, various esters of acrylic acid, various esters of methacrylic acid, crotonic acid, itaconic acid, maleic acid, maleic anhydride, esters of maleic acid, esters of maleic anhydride, acrylonitrile, and methacrylic acid. It is formed by polymerizing at least one monomer such as lonitrile, acrylamide, methacrylamide, vinyl chloride, and vinyl acetate. Acrylic resin is useful in that it can prevent cracks caused by flux residue even in environments with large temperature differences and large thermal shocks. Among these acrylic resins, acrylic resins polymerized with monomers containing methacrylic acid and a monomer having an alkyl group having 2 to 6 carbon atoms, and monomers containing methacrylic acid and a monomer having an alkyl group having 2 to 6 carbon atoms. An acrylic resin polymerized with is preferred. Such an acrylic resin is preferable because it suppresses the stickiness of the flux residue (solidified flux) that is formed and has a good crack suppressing effect.

The blending amount of component (A) is preferably 30% by mass or more and 70% by mass or less, more preferably 35% by mass or more and 60% by mass or less, and 40% by mass or less, based on 100% by mass of the flux composition. % or more and 50% by mass or less is particularly preferable. If the blending amount of component (A) is above the lower limit, it is possible to prevent oxidation of the copper foil surface of the soldering land and make it easier to wet the surface with molten solder, improving so-called solderability, and ensuring sufficient solder balls. can be suppressed to Moreover, if the blending amount of component (A) is below the above-mentioned upper limit, the amount of flux remaining can be sufficiently suppressed.

[(B) Component]
The (B) activator used in this embodiment needs to contain (B1) a compound having a quinoline skeleton. This component (B1) has the effect of suppressing the generation of solder balls. This component (B1) preferably has one or more hydroxyl groups in one molecule.
The component (B1) is preferably a compound represented by the following general formula (1).

In general formula (1), X ¹ to X ⁷ are independently hydrogen, a hydroxyl group, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms, and any one of X ² to X ⁷ Two may constitute a ring.
It is particularly preferred that X ¹ is hydrogen.
X ² to X ⁷ are preferably hydrogen, a hydroxyl group, a methyl group, or a methoxy group, and more preferably hydrogen or a methyl group.

Component (B1) includes 8-quinolinol, 2-methyl-8-quinolinol, and 5-methyl-8-quinolinol. These may be used alone or in combination of two or more.

The blending amount of component (B1) is preferably 0.1% by mass or more and 10% by mass or less, and preferably 0.2% by mass or more and 8% by mass or less, based on 100% by mass of the flux composition. It is more preferably 0.8% by mass or more and 5% by mass or less, even more preferably 1.5% by mass or more and 2.5% by mass or less. If the amount of component (B1) is at least the above-mentioned lower limit, it tends to further improve the effect of suppressing solder balls, and on the other hand, when it is at or below the above-mentioned upper limit, it tends to be able to maintain the insulation properties of the flux composition.

It is preferable that the component (B) further contains (B2) an azole. This component (B2) has the effect of assisting the effect of the component (B1) and improving the effect of suppressing solder balls.
Examples of the component (B2) include pyrrole compounds, imidazole compounds, pyrazole compounds, and triazole compounds. These may be used alone or in combination of two or more. Moreover, among these, imidazole compounds or triazole compounds are preferable from the viewpoint of solder meltability. Moreover, it is particularly preferable to use an imidazole compound and a triazole compound together.
Examples of the imidazole compound include 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, and 1,2-dimethylimidazole. Among these, 2-ethyl-4-methylimidazole is preferred.
Examples of triazole compounds include benzotriazole, 1,2,3-triazole, and 1,2,4-triazole. Among these, benzotriazole is preferred.

The blending amount of component (B2) is preferably 0.1% by mass or more and 8% by mass or less, and preferably 0.5% by mass or more and 5% by mass or less, based on 100% by mass of the flux composition. More preferably, it is 1% by mass or more and 3% by mass or less. If the amount of component (B2) is at least the above-mentioned lower limit, the effect of suppressing solder balls tends to be further improved, while if it is below the above-mentioned upper limit, the insulation properties of the flux composition tend to be maintained.

It is preferable that component (B) further contains (B3) an organic acid. This component (B3) has the effect of assisting the effect of the component (B1) and improving the effect of suppressing solder balls.
Component (B3) includes monocarboxylic acids, dicarboxylic acids, and other organic acids. These may be used alone or in combination of two or more.
Monocarboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, capric acid, lauric acid, myristic acid, pentadecyl acid, palmitic acid, margaric acid, stearic acid, tuberculostearic acid. , arachidic acid, behenic acid, lignoceric acid, and glycolic acid.
Dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, fumaric acid, maleic acid, tartaric acid, and diglycolic acid. Can be mentioned. Among these, from the viewpoint of active action, adipic acid or suberic acid is preferred, and suberic acid is particularly preferred.
Other organic acids include dimer acid, trimer acid, levulinic acid, lactic acid, acrylic acid, benzoic acid, salicylic acid, anisic acid, citric acid, and picolinic acid. Among these, it is more preferable to use picolinic acid.
As component (B3), it is preferable to use a plurality of organic acids in combination, and it is particularly preferable to use suberic acid and picolinic acid in combination.

The blending amount of component (B3) is preferably 0.1% by mass or more and 12% by mass or less, and preferably 0.5% by mass or more and 8% by mass or less, based on 100% by mass of the flux composition. More preferably, it is 1% by mass or more and 5% by mass or less. If the amount of component (B3) is at least the above-mentioned lower limit, it tends to further improve the effect of suppressing solder balls, while when it is at or below the above-mentioned upper limit, it tends to maintain the insulation properties of the flux composition.

Component (B) may further contain other active agents (hereinafter also referred to as component (B4)) in addition to components (B1) to (B3), as long as the objects of the present invention can be achieved. Examples of the component (B4) include halogen-based activators and amine-based activators other than the components (B1) and (B2). However, the total blending amount of components (B1) to (B3) is preferably 50% by mass or more, more preferably 70% by mass or more, based on 100% by mass of component (B). It is particularly preferable that the content is 90% by mass or more.

The blending amount of component (B) is preferably 0.5% by mass or more and 20% by mass or less, more preferably 1% by mass or more and 15% by mass or less, based on 100% by mass of the flux composition. , it is particularly preferably 1.5% by mass or more and 10% by mass or less. If the blending amount of component (B) is at least the above-mentioned lower limit, there is a tendency for the activation effect to be improved, whereas, on the other hand, when it is below the above-mentioned upper limit, the insulation properties of the flux composition tend to be maintained.

[(C) Component]
The flux composition according to the present embodiment preferably further contains (C) a thixotropic agent from the viewpoint of printability and the like. Examples of the thixotropic agent used here include hydrogenated castor oil, amides, kaolin, colloidal silica, organic bentonite, and glass frit. These may be used alone or in combination of two or more.

The blending amount of component (C) is preferably 1% by mass or more and 20% by mass or less, more preferably 2% by mass or more and 12% by mass or less, based on 100% by mass of the flux composition. If the amount is less than the lower limit, thixotropy is not obtained and sag tends to occur, while if it exceeds the upper limit, the thixotropy is too high and printing defects tend to occur.

[solvent]
The flux composition according to the present embodiment preferably further contains a solvent from the viewpoint of printability and the like. As the solvent used here, any known solvent can be used as appropriate. As such a solvent, it is preferable to use a solvent having a boiling point of 170° C. or higher. Moreover, glycol solvents are preferred.
Examples of such solvents include diethylene glycol, dipropylene glycol, triethylene glycol, hexylene glycol, hexyl diglycol, 1,5-pentanediol, methyl carbitol, butyl carbitol, and 2-ethylhexyl diglycol (EHDG). , octanediol, phenyl glycol, diethylene glycol monohexyl ether, tetraethylene glycol dimethyl ether, and dibutyl maleic acid. These solvents may be used alone or in combination of two or more.

When a solvent is used, the amount thereof is preferably 10% by mass or more and 75% by mass or less, more preferably 20% by mass or more and 65% by mass or less, based on 100% by mass of the flux composition. If the blending amount of the solvent is within the above range, the viscosity of the resulting solder composition can be adjusted to an appropriate range.

[Antioxidant]
The flux composition according to the present embodiment preferably further contains an antioxidant from the viewpoint of solder meltability. As the antioxidant used here, any known antioxidant can be used as appropriate. Examples of antioxidants include sulfur compounds, hindered phenol compounds, and phosphite compounds. Among these, hindered phenol compounds are preferred.

Examples of hindered phenol compounds include pentaerythritol tetrakis [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], bis[3-(3-tert-butyl-4-hydroxy-5-methyl) phenyl)propionic acid][ethylenebis(oxyethylene)], N,N'-bis[2-[2-(3,5-di-tert-butyl-4-hydroxyphenyl)ethylcarbonyloxy]ethyl]oxamide, N,N'-bis{3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl}hydrazine and 2-[1-(2-hydroxy-3,5-di-tert acrylate) -pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl and the like. Among these, from the viewpoint of further suppressing effect on solder balls, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentyl acrylate Preference is given to using phenyl.

When using an antioxidant, the amount thereof is preferably 0.1% by mass or more and 5% by mass or less, and 0.5% by mass or more and 3% by mass or less, based on 100% by mass of the flux composition. It is more preferable. If the amount of the antioxidant is at least the above-mentioned lower limit, it tends to improve the solder melting properties, and on the other hand, when it is at least the above-mentioned upper limit, it tends to be able to maintain the insulation properties of the flux composition.

[Other ingredients]
In addition to the (A) component, (B) component, (C) component, solvent, and antioxidant, the flux composition used in this embodiment may contain other additives as necessary. of resin can be added. Other additives include antifoaming agents, modifiers, matting agents, foaming agents, and the like. The blending amount of these additives is preferably 0.01% by mass or more and 5% by mass or less based on 100% by mass of the flux composition.

[Solder composition]
Next, the solder composition according to this embodiment will be explained. The solder composition according to this embodiment contains the above-described flux composition according to this embodiment and (D) solder powder described below.
The blending amount of the flux composition is preferably 5% by mass or more and 35% by mass or less, more preferably 7% by mass or more and 15% by mass or less, and 8% by mass based on 100% by mass of the solder composition. It is particularly preferable that the amount is 12% by mass or less. If the amount of flux composition is less than 5% by mass (if the amount of solder powder is more than 95% by mass), there is not enough flux composition as a binder, so the flux composition and solder powder are mixed. On the other hand, when the blending amount of the flux composition exceeds 35% by mass (when the blending amount of the solder powder is less than 65% by mass), when the resulting solder composition is used, It tends to be difficult to form a sufficient solder joint.

Although the solder composition according to the present embodiment is halogen-free or non-halogen type, it can sufficiently suppress the generation of solder balls. Even if a solder composition is compatible with halogen-free printed wiring boards, halogen-free or non-halogen type solder compositions can suppress the generation of solder balls to the same level as when using a halogen-based activator. It can be particularly suitably used as
The halogen-free solder composition has a chlorine concentration of 900 mass ppm or less (more preferably 100 mass ppm or less, particularly preferably 0 mass ppm) and a bromine concentration of 900 mass ppm or less (more preferably 100 mass ppm or less). ppm or less, particularly preferably 0 mass ppm), the iodine concentration is 900 mass ppm or less (more preferably 100 mass ppm or less, particularly preferably 0 mass ppm), and the halogen concentration is 1500 mass ppm. or less (more preferably 300 mass ppm or less, particularly preferably 0 mass ppm). Note that examples of the halogen include fluorine, chlorine, bromine, and iodine.
Note that the chlorine concentration, bromine concentration, and halogen concentration in the solder composition can be measured according to the method described in JEITA ET-7304A. In addition, it can be simply calculated from the components of the solder composition and their amounts.

[(D) Component]
The solder powder (D) used in this embodiment is preferably composed of only lead-free solder powder, but may be leaded solder powder. The solder alloys in this solder powder include tin (Sn), copper (Cu), zinc (Zn), silver (Ag), antimony (Sb), lead (Pb), indium (In), bismuth (Bi), It is preferable to contain at least one member selected from the group consisting of nickel (Ni), cobalt (Co), and germanium (Ge).
The solder alloy in this solder powder is preferably an alloy containing tin as a main component. Moreover, it is more preferable that this solder alloy contains tin, silver, and copper. Furthermore, this solder alloy may contain at least one of antimony, bismuth, and nickel as an additive element. According to the flux composition of the present embodiment, the generation of voids can be suppressed even when a solder alloy containing easily oxidizable additive elements such as antimony, bismuth, and nickel is used.
Here, the lead-free solder powder refers to a solder metal or alloy powder that does not contain lead. However, although it is permissible for lead to exist as an unavoidable impurity in the lead-free solder powder, in this case, the amount of lead is preferably 300 mass ppm or less.

Specifically, lead-free solder powder alloys include Sn-Ag-Cu, Sn-Cu, Sn-Ag, Sn-Bi, Sn-Ag-Bi, and Sn-Ag-Sb. -Bi series, Sn-Ag-Cu-Bi series, Sn-Ag-Cu-Ni series, Sn-Ag-Cu-Bi-Sb series, Sn-Ag-Bi-In series, Sn-Ag-Cu-Bi- Examples include In-Sb type.
Note that the flux composition according to the present embodiment can sufficiently suppress the generation of solder balls even when the flux composition is based on a solder alloy such as a Sn--Bi system. Therefore, when using component (D) of a solder alloy system containing Bi, the effect of the flux composition according to the present embodiment can be particularly exhibited. Specific solder alloy systems include Sn-Bi, Sn-Ag-Bi, Sn-Ag-Sb-Bi, Sn-Bi-Sb-In, and Sn-Bi-Sb-In-Ni-Co. and Sn-Bi-Sb-Cu-In-Ni-Co systems. Among these alloy systems, Sn-Bi system, Sn-Ag-Bi system, or Sn-Ag-Sb-Bi system is preferred. In addition, specific solder alloy compositions include Sn-57Bi-1Ag, Sn-58Bi, Sn-35Bi-1Ag, Sn-45Bi-1.5Sb-0.5Ag, Sn-50Bi-1Sb-0.5In, Sn Examples include -50Bi-1Sb-0.5In-0.05Ni-0.1Co, and Sn-50Bi-1Sb-2Cu-0.5In-0.05Ni-0.1Co. Among these alloy compositions, Sn-57Bi-1Ag, Sn-58Bi, Sn-35Bi-1Ag, and Sn-45Bi-1.5Sb-0.5Ag are preferred.

The average particle diameter of component (D) is usually 1 μm or more and 40 μm or less, but from the viewpoint of being compatible with electronic boards with narrow soldering pad pitches, it is more preferably 1 μm or more and 35 μm or less, and 2 μm or more and 35 μm or less. It is even more preferable that it is below, and it is especially preferable that it is 3 μm or more and 32 μm or less. Note that the average particle diameter can be measured using a dynamic light scattering type particle diameter measuring device.

[Method for manufacturing solder composition]
The solder composition of the present embodiment can be manufactured by blending the above-described flux composition and the above-described solder powder (D) in the above-described predetermined ratio and stirring and mixing.

[Electronic substrate]
Next, the electronic board according to this embodiment will be explained. The electronic board according to this embodiment is characterized in that it includes a soldering part using the solder composition according to the above-described embodiment. The electronic board according to this embodiment can be manufactured by mounting electronic components on an electronic board (printed wiring board, etc.) using the solder composition.
Examples of the coating device used here include a screen printer, a metal mask printer, a dispenser, a jet dispenser, and the like.
In addition, the electronic components are mounted on the electronic board through a reflow process in which electronic components are placed on the solder composition coated with a coating device, heated under predetermined conditions in a reflow oven, and then mounted on the printed wiring board. can.

In the reflow process, electronic components are placed on the solder composition and heated under predetermined conditions in a reflow oven. Through this reflow process, sufficient solder bonding can be achieved between the electronic component and the printed wiring board. As a result, electronic components can be mounted on the printed wiring board.
Reflow conditions may be appropriately set depending on the melting point of the solder. For example, the preheat temperature is preferably 90°C or more and 130°C or less, more preferably 100°C or more and 120°C or less. The preheat time is preferably 40 seconds or more and 120 seconds or less, and more preferably 60 seconds or more and 100 seconds or less. The peak temperature is preferably 160°C or more and 190°C or less, more preferably 180°C or more and 190°C or less. Further, the holding time at a temperature of 140° C. or higher is preferably 30 seconds or more and 120 seconds or less, and more preferably 80 seconds or more and 120 seconds or less.

Further, the flux composition, solder composition, and electronic board according to the present embodiment are not limited to the above embodiments, and modifications, improvements, etc. within the scope of achieving the purpose of the present invention are included in the present invention. It is something.
For example, in the electronic board, the printed wiring board and the electronic component are bonded together by a reflow process, but the present invention is not limited to this. For example, instead of the reflow process, the printed wiring board and the electronic component may be bonded by a process of heating the solder composition using laser light (laser heating process). In this case, the laser light source is not particularly limited, and can be appropriately employed depending on the wavelength matched to the absorption band of the metal. Examples of laser light sources include solid lasers (ruby, glass, YAG, etc.), semiconductor lasers (GaAs, InGaAsP, etc.), liquid lasers (dye, etc.), and gas lasers (He-Ne, Ar, CO ₂ , etc.). excimer, etc.).

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples in any way. The materials used in the Examples and Comparative Examples are shown below.
((A) component)
Rosin resin A: Acrylic acid-modified hydrogenated rosin, product name "Pine Crystal KE-604", manufactured by Arakawa Chemical Co., Ltd. Rosin resin B: fully hydrogenated rosin, product name "Foral AX", manufactured by Rika Fine Tech Co., Ltd. ( (B1) component)
Quinoline compound A: 8-quinolinol Quinoline compound B: 2-methyl-8-quinolinol ((B2) component)
Azole A: Benzotriazole Azole B: 2-ethyl-4-methylimidazole, trade name "2E4MZ", Shikoku Kasei Kogyo Co., Ltd. (component (B3))
Organic acid A: picolinic acid Organic acid B: suberic acid (component (C))
Thixotropic agent A: Brand name “Slipax ZHH”, manufactured by Nippon Kasei Co., Ltd. Thixotropic agent B: Brand name “Himakou”, manufactured by KF Trading Co., Ltd. (other ingredients)
Solvent: diethylene glycol mono-2-ethylhexyl ether (2-ethylhexyldiglycol (EHDG), boiling point: 272°C), Nippon Nyukazai Co., Ltd. Antioxidant A: N,N'-bis{3-(3,5-di- tert-butyl-4-hydroxyphenyl)propionyl}hydrazine, trade name "Irganox MD-1024", manufactured by BASF Antioxidant B: acrylic acid 2-[1-(2-hydroxy-3,5-di-tert) -pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl, trade name "Sumilizer GS", manufactured by Sumitomo Chemical Co., Ltd. (component (D))
Solder powder A: Alloy composition is Sn-57Bi-1Ag, particle size distribution is 20 to 38 μm
Solder powder B: Alloy composition is Sn-45Bi-1.5Sb-0.5Ag, particle size distribution is 20 to 38 μm
Solder powder C: Alloy composition is Sn-58Bi, particle size distribution is 20 to 38 μm
Solder powder D: Alloy composition is Sn-50Bi-1Sb-0.5In, particle size distribution is 20 to 38 μm
Solder powder E: Alloy composition is Sn-50Bi-1Sb-0.5In-0.05Ni-0.1Co, particle size distribution is 20 to 38 μm
Solder powder F: Alloy composition is Sn-50Bi-1Sb-2Cu-0.5In-0.05Ni-0.1Co, particle size distribution is 20 to 38 μm

[Example 1]
Rosin Resin A 25% by mass, Rosin Resin B 21% by mass, Quinoline Compound A 2% by mass, Azoles A 0.5% by mass, Azoles B 1% by mass, Organic Acid A 1% by mass, Organic Acid B 3% by mass, Solvent 37% by mass. , 2% by mass of antioxidant A, 5% by mass of thixotropic agent A, and 2.5% by mass of thixotropic agent B were placed in a container and mixed using a planetary mixer to obtain a flux composition.
Thereafter, 10.6% by mass of the obtained flux composition, 0.6% by mass of solvent, and 88.8% by mass of solder powder A (total 100% by mass) were put into a container and mixed with a planetary mixer. A solder composition was prepared.

[Examples 2 to 15]
A solder composition was obtained in the same manner as in Example 1 except that each material was blended according to the composition shown in Table 1.
[Comparative example 1]
A solder composition was obtained in the same manner as in Example 1 except that each material was blended according to the composition shown in Table 1.

<Evaluation of solder composition>
Evaluation of the solder composition (solder ball test, ball between pins) was performed in the following manner. The results obtained are shown in Table 1.
(1) Solder ball test A solder ball test was conducted with reference to the description in IPC TM-650 2.4.43. Specifically, a sample was prepared by printing one circular piece of the solder composition with a diameter of 6.5 mm on a ceramic substrate with a thickness of 0.6 mm to 0.8 mm using a metal screen. The above sample is placed on a hot plate set at 180°C, and 5 seconds after melting, it is taken out and held horizontally to cool. The number and size of solder balls in the solder were observed using a 20x microscope and judged based on the following criteria. Note that "Preferred", "Acceptable", "Unacceptable;Clusters", and "Unacceptable" conform to the evaluation criteria described in IPC TM-650 2.4.43.
◎: "Preferred", flux remains or there are almost no solder balls around (about a few).
○: "Acceptable", solder balls are sparsely generated in or around the flux residue. However, the solder balls do not exist in a dense state.
×: "Unacceptable;Clusters", solder balls are densely generated in the flux residue.
XX: "Unacceptable", solder balls are continuously generated all around the flux residue.
(2) Ball between pins On a substrate having 80 0.4 mm x 3.0 mm copper pads spaced at 0.8 mm intervals, a solder composition was applied at a printing speed of 50 mm/sec using a metal mask with a corresponding pattern. Printing was performed at a printing pressure of 0.2N. Thereafter, the solder composition was melted in a reflow oven (manufactured by Tamura Seisakusho Co., Ltd.), and soldering was performed to prepare a test board. The test board was observed with a magnifying glass, the number of solder balls between pins (number of balls between pins, unit: pieces/pin) was measured, and the balls between pins were evaluated according to the following criteria. Note that the reflow conditions are that the preheat temperature is 100 to 120°C (about 80 seconds), the time at which the temperature is 140°C or higher is about 100 seconds, and the peak temperature is about 185°C.
◎: The number of balls between pins is less than 4.
○: The number of balls between pins is 4 or more and less than 10.
Δ: The number of balls between pins is 10 or more and less than 15.
×: The number of balls between pins is 15 or more.

As is clear from the results shown in Table 1, it was confirmed that the solder compositions of the present invention (Examples 1 to 15) had good results in all the solder ball tests and pin-to-pin balls. Note that the solder compositions of Examples 1 to 15 do not contain a halogen-based activator, so they are non-halogen type solder compositions.
Therefore, it was confirmed that the solder composition of the present invention can sufficiently suppress the generation of solder balls even though it is halogen-free or non-halogen type.

The flux composition and solder composition of the present invention can be suitably used as a technique for mounting electronic components on electronic boards such as printed wiring boards of electronic devices.

Claims (9)

(A) a resin, and (B) an activator;
The component (B) contains (B1) a compound having a quinoline skeleton.
Flux composition. The flux composition according to claim 1,
The component (B1) is a compound represented by the following general formula (1),
Flux composition.

(In general formula (1), X ¹ to X ⁷ are independently hydrogen, a hydroxyl group, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having ¹ to ³ carbon atoms; or two may form a ring.) In the flux composition according to claim 1 or 2,
The component (B) further contains (B2) an azole,
Flux composition. In the flux composition according to claim 1 or 2,
The component (B) further contains (B3) an organic acid.
Flux composition. In the flux composition according to claim 1 or 2,
further containing (C) a thixotropic agent;
Flux composition. Containing the flux composition according to claim 1 or claim 2 and (D) solder powder,
Solder composition. The solder composition according to claim 6,
The alloy system of the component (D) is Sn-Bi system, Sn-Ag-Bi system, Sn-Ag-Sb-Bi system, Sn-Bi-Sb-In system, Sn-Bi-Sb-In-Ni- Co-based and Sn-Bi-Sb-Cu-In-Ni-Co based,
Solder composition. The solder composition according to claim 6,
The alloy composition of the component (D) is Sn-57Bi-1Ag, Sn-58Bi, Sn-35Bi-1Ag, Sn-45Bi-1.5Sb-0.5Ag, Sn-50Bi-1Sb-0.5In, Sn- 50Bi-1Sb-0.5In-0.05Ni-0.1Co, and Sn-50Bi-1Sb-2Cu-0.5In-0.05Ni-0.1Co,
Solder composition. A soldered portion using the solder composition according to claim 6,
Electronic substrate.