CN113905847B

CN113905847B - Solder joint failure inhibitor, flux, and solder paste

Info

Publication number: CN113905847B
Application number: CN202180003711.2A
Authority: CN
Inventors: 永井智子; 髙木和顺; 浅见爱; 髙木善范
Original assignee: Senju Metal Industry Co Ltd
Current assignee: Senju Metal Industry Co Ltd
Priority date: 2020-03-30
Filing date: 2021-03-11
Publication date: 2023-09-01
Anticipated expiration: 2041-03-11
Also published as: JP6845452B1; JP2021159921A; WO2021200010A1; TWI748901B; TW202138470A; CN113905847A

Abstract

Provided are a solder joint failure inhibitor, a flux, and a solder paste, which can inhibit the occurrence of joint failure. The flux of the present application comprises a base resin, an activator, a thixotropic agent, a solvent, and a solder joint failure inhibitor, which is a solder joint failure inhibitor comprising a compound represented by the following chemical formula (11): in the chemical formula (11), R ⁹ And R is ¹⁰ Each independently is a saturated or unsaturated, straight, branched or cyclic alkyl group having 1 to 18 carbon atoms, R ¹¹ And R is ¹² Respectively and independently are carboxyl, or R ¹¹ And R is ¹² Can also be crosslinked to form carboxylic anhydride groups.

Description

Solder joint failure inhibitor, flux, and solder paste

Technical Field

The application relates to a solder joint failure inhibitor, a flux and a solder paste.

Background

In recent years, with the reduction in weight and size of electronic devices, semiconductor packages such as BGA (Ball Grid Array) have been used (for example, patent document 1).

Prior art literature

Patent literature

Patent document 1: JP-A2008-71779

Disclosure of Invention

Problems to be solved by the application

However, since a plurality of materials are used for the semiconductor package such as BGA, the semiconductor package is bent due to the difference in thermal expansion coefficient. In addition, as the semiconductor package is thinned, the amount of warpage of the package becomes large. Therefore, the solder bump and the solder paste are detached from the substrate, and the pad (soldered portion) is not subjected to oxidation removal by the flux, leaving an oxide film on the pad surface. In addition, even if the solder paste and the substrate come into contact again, the activity (wettability) of the flux is reduced by heat, and thus, similarly, the removal by oxidation of the flux is insufficient. Therefore, the electronic component and the substrate are not bonded, and a problem of poor bonding occurs.

Accordingly, an object of the present application is to provide a solder joint failure inhibitor, flux, and solder paste, which can suppress occurrence of joint failure.

Means for solving the problems

To achieve the above object, the solder joint failure inhibitor (hereinafter also referred to as "inhibitor") of the present application comprises a compound represented by the following chemical formula (11):

[ chemical 11]

In the chemical formula (11) described above,

R ⁹ and R is ¹⁰ Each independently represents a saturated or unsaturated, linear, branched or cyclic alkyl group having 1 to 18 carbon atoms,

R ¹¹ and R is ¹² Each of which is independently a carboxyl group,

or R is ¹¹ And R is ¹² Can also be crosslinked to form carboxylic anhydride groups.

The flux of the present application comprises a matrix resin, an activator, a thixotropic agent, a solvent and a solder joint failure inhibitor,

the solder joint failure inhibitor is the solder joint failure inhibitor of the present application.

The solder paste of the present application contains a flux, which is the flux of the present application, and a solder powder.

ADVANTAGEOUS EFFECTS OF INVENTION

The application can inhibit the occurrence of poor solder joint.

Detailed Description

< solder poor bonding inhibitor >

The solder joint failure inhibitor of the present application comprises a compound of the following chemical formula (11).

[ chemical 11]

In the chemical formula (11) described above,

R ¹¹ and R is ¹² Each of which is independently a carboxyl group,

The solder joint failure inhibitor of the present application is characterized by comprising the compound of the formula (11), and other constitution and conditions are not particularly limited.

The present inventors have made intensive studies and found that the present application can be made to suppress poor adhesion by allowing the inhibitor of the present application to coexist, and established the present application. Therefore, the solder joint failure can be suppressed by the inhibitor of the present application.

In the present application, the term "poor bonding" means, for example, that no bonding is formed between the solder and the soldering target (Non Wet Open: NWO). The "poor bonding" can be measured, for example, by resistance measurement. In the present application, the term "suppression of the defective bonding" means that the occurrence frequency of defective bonding is significantly reduced when bonding is performed using, for example, a solder or a solder paste having a control having the same composition except that the inhibitor of the present application is not included. The occurrence frequency of the above-described poor joining can be performed based on NWO evaluation experiments described later.

In the chemical formula (11), R ⁹ And R is ¹⁰ Each independently represents a saturated or unsaturated, linear, branched or cyclic alkyl group having 1 to 18 carbon atoms. R is R ⁹ Preferably a saturated straight-chain alkyl group having 1 to 18 carbon atoms, more preferably a saturated straight-chain alkyl group having 4 to 8 carbon atoms, and still more preferably a pentyl group (-C) ₅ H ₁₁ ) Hexyl (-C) ₆ H ₁₃ ) Or heptyl (-C) ₇ H ₁₅ )。R ¹⁰ Preferably a saturated straight-chain alkyl group having 1 to 18 carbon atoms, more preferably a saturated straight-chain alkyl group having 5 to 9 carbon atoms, and still more preferably a hexyl group (-C) ₆ H ₁₂ ) Heptyl (-C) ₇ H ₁₄ ) Or octyl (-C) ₈ H ₁₆ ). In the chemical formula (11), R ⁹ For example, a saturated straight-chain alkyl group having 1 to 18 carbon atoms, R ¹⁰ Is a saturated straight-chain alkyl group having 1 to 18 carbon atoms.

R ¹¹ And R is ¹² Each independently is a carboxyl group, or may be crosslinked to form a carboxylic anhydride group. The carboxylic anhydride group refers to, for example, a substituent containing a carboxylic anhydride. The crosslinking is, for example, R ¹¹ And R is ¹² Forming a ring structure.

In one embodiment, the compound represented by the chemical formula (11) is preferably a compound represented by the following chemical formula (12).

[ chemical 12]

In one embodiment, the compound represented by the chemical formula (11) is preferably a compound represented by the following chemical formula (13).

[ chemical 13]

The compound represented by the chemical formula (11) can be produced, for example, by reacting a compound represented by the following chemical formula (15) with maleic anhydride. In the above reaction, the amount ratio of the compound represented by the following chemical formula (15) may be set to, for example, equal to or more than the equivalent of maleic anhydride, and preferably 1 to 1.5 times the equivalent. Specifically, the compound represented by the formula (15) may be, for example, 0.01 to 3% by weight, preferably 0.01 to 1% by weight, based on maleic anhydride. The reaction temperature is, for example, 30 to 150℃and preferably 40 to 100 ℃. The reaction is carried out, for example, under an atmosphere of an inert gas such as nitrogen or a rare gas for 0.5 to 20 hours. Preferably 0.5 to 10 hours.

[ 15]

R ⁹ -CH＝CH-CH＝CH-R ¹⁰ -COOH…(15)

< flux >

The flux of the present application comprises a matrix resin, an activator, a thixotropic agent, a solvent and the solder joint failure inhibitor of the present application as described above. The flux of the present application is characterized by comprising the inhibitor of the present application, and other constitution and conditions are not particularly limited. The flux of the present application may be used in the description of the inhibitor of the present application. The flux of the present application can suppress occurrence of poor bonding at the time of solder bonding.

The matrix resin is not particularly limited, and examples thereof include polyethylene glycol, rosin (rosin resin), and the like. Examples of the rosin include raw rosin such as gum rosin, wood rosin, and tall oil rosin, and derivatives obtained from the raw rosin. Such derivatives can be exemplified by refined rosin; hydrogenated rosin; disproportionated rosin; polymerized rosin, purified products, hydrides and disproportionations of said polymerized rosin, alpha, beta unsaturated carboxylic acid modifications (acrylated rosin, maleated rosin, fumarated rosin, etc.), and purified products, hydrides and disproportionations of said alpha, beta unsaturated carboxylic acid modifications, etc. For example, one kind of rosin may be used alone, or two or more kinds may be used. In addition, the matrix resin may further contain at least one resin selected from the group consisting of terpene resins, modified terpene resins, terpene phenolic resins, modified terpene phenolic resins, styrene resins, modified styrene resins, xylene resins, and modified xylene resins, for example, in addition to the rosin resin. Examples of the modified terpene resin include aromatic modified terpene resins, hydrogenated aromatic modified terpene resins, and the like. Examples of the modified terpene phenolic resin include hydrogenated terpene phenolic resins. Examples of the modified styrene resin include styrene acrylic resin and styrene maleic resin. Examples of the modified xylene resin include phenol modified xylene resin, alkylphenol modified xylene resin, phenol modified first-order xylene resin, polyol modified xylene resin, polyoxyethylene addition xylene resin, and the like.

The blending amount of the matrix resin is not particularly limited, and is, for example, 10 mass% or more and 60 mass% or less (10 to 60 mass%), preferably 20 mass% or more and 50 mass% or less (20 to 50 mass%) with respect to the total amount of the flux.

The activator has the function of reducing and removing oxides on the surface of the solder part and the powder solder to clean, enhancing the wettability of the molten solder and causing the molten solder to metallically adhere to the solder joint. Examples of the activator include organic acids, organic halides, amine hydrogen halides, and the like. Examples of the organic acid include malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, suberic acid, pimelic acid, sebacic acid, dodecanedioic acid, eicosanedioic acid, glycolic acid, salicylic acid, diglycolic acid, pyridine-2-carboxylic acid, phenylsuccinic acid, phthalic acid, fumaric acid, maleic acid, benzoic acid, terephthalic acid, lauric acid, stearic acid, 12-hydroxystearic acid, 2-bis (hydroxymethyl) propionic acid, and the like. Examples of the organic halide include 1-bromo-2-propanol, 3-bromo-1, 2-propanediol, 1-bromo-2-butanol, 1, 3-dibromo-2-propanol, 2, 3-dibromo-1-propanol, 1, 4-dibromo-2-butanol, 2, 3-dibromo-1, 4-butanediol, trans-2, 3-dibromo-2-butene-1, 4-diol, and the like. Amine hydrogen halide salts are compounds obtained by reacting an amine such as ethylamine, diethylamine, triethylamine, ethylenediamine, cyclohexylamine, 1, 3-diphenylguanidine, 1, 3-di-o-tolylguanidine, 1-o-tolylguanidine, etc., with a hydrogen halide such as hydrogen chloride, bromine, iodine. The activator may be used alone or in combination of two or more kinds. The amount of the activator to be blended is not particularly limited, and is, for example, 1% by mass or more and 20% by mass or less (1 to 20% by mass), preferably 5% by mass or more and 15% by mass or less (5 to 15% by mass) relative to the total amount of the flux.

The thixotropic agent has the effects of preventing separation of the flux from other components, improving storage stability, and improving flow characteristics to improve transferability at printing and discharge. Examples of the thixotropic agent include wax-type thixotropic agents and amide-type thixotropic agents. Examples of the wax thixotropic agent include hydrogenated castor oil and the like. Examples of the amide thixotropic agent include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide, saturated fatty acid amide, oleic acid amide, erucic acid amide, unsaturated fatty acid amide, p-toluenemethane amide, aromatic amide, methylenedistearic acid amide, ethylenebislauric acid amide, ethylenebishydroxystearic acid amide, saturated fatty acid bisamide, methylenebisoleic acid amide, unsaturated fatty acid bisamide, m-xylylenebisstearic acid amide, aromatic bisamide, saturated fatty acid polyamide, unsaturated fatty acid polyamide, aromatic polyamide, substituted amide, methylol stearic acid amide, methylol amide, fatty acid ester amide, and the like. The thixotropic agent may be used alone or in combination of two or more kinds. The amount of the thixotropic agent to be blended is not particularly limited, and is, for example, 1 mass% or more and 15 mass% or less (1 to 15 mass%), preferably 5 mass% or more and 10 mass% or less (5 to 10 mass%) with respect to the total amount of the flux.

Examples of the solvent include alcohol solvents, glycol ether solvents, ester solvents, and terpineols. Examples of the alcoholic solvent include 1, 2-butanediol, isobornyl cyclohexanol, 2, 4-diethyl-1, 5-pentanediol, 2-dimethyl-1, 3-propanediol, 2, 5-dimethyl-2, 5-hexanediol, 2-butyl-2-ethyl-1, 3-propanediol, 2, 5-dimethyl-3-hexyne-2, 5-diol, 2, 3-dimethyl-2, 3-butanediol, 2-methylpentane-2, 4-diol, 1-tris (hydroxymethyl) ethane 2-ethyl-2-hydroxymethyl-1, 3-propanediol, 2' -oxybis (methylene) bis (2-ethyl-1, 3-propanediol), 2-bis (hydroxymethyl) -1, 3-propanediol, 1,2, 6-hexanetriol, bis [2, 2-tris (hydroxymethyl) ethyl ] ether, 1-ethynyl-1-cyclohexanol, 1, 4-cyclohexanediol, 1, 4-cyclohexanedimethanol, 3, 6-dimethyl-4-octyne-3, 6-diol, 2,4,7, 9-tetramethyl-5-decyne-4, 7-diol, and the like. Examples of the glycol ether solvents include diethylene glycol mono-2-ethylhexyl ether, ethylene glycol monophenyl ether, diethylene glycol monohexyl ether, diethylene glycol dibutyl ether, triethylene glycol monobutyl ether, tripropylene glycol methyl ether, dipropylene glycol butyl ether, tripropylene glycol butyl ether, triethylene glycol butyl methyl ether, and tetraethylene glycol dimethyl ether. Examples of the ester solvents include diisobutyl succinate, dibutyl succinate, dimethyl adipate, diethyl adipate, dibutyl adipate, diisopropyl adipate, diisobutyl adipate, diisodecyl adipate, dibutyl maleate, dimethyl sebacate, diethyl sebacate, dibutyl sebacate, dioctyl sebacate, diisopropyl sebacate and the like. The solvent may be used alone or in combination of two or more kinds.

The blending amount of the solvent is not particularly limited, and may be, for example, the remainder of the other components. Specifically, the amount of the solvent to be blended is, for example, 10 mass% or more and 60 mass% or less (10 to 60 mass%), preferably 25 mass% or more and 50 mass% or less (25 to 50 mass%) with respect to the total amount of the flux.

In the flux of the present application, the inhibitor may be used alone or in combination of two or more kinds. The inhibitor is preferably a compound represented by the chemical formula (12) or (13), or a mixture thereof, for example, from the viewpoint of better inhibiting solder joint failure.

The amount of the inhibitor to be blended, that is, the amount of the compound represented by the chemical formula (11) may exceed 0 mass% with respect to the entire mass of the flux, and is preferably 5 mass% or more, 25 mass% or less (5 to 25 mass%), 5 mass% or more, 24 mass% or less (5 to 24 mass%), or 5 mass% or more, 20 mass% or less (5 to 20 mass%), more preferably 10 mass% or more, 25 mass% or less (10 to 25 mass%), 10 mass% or more, 24 mass% or less (10 to 24 mass%), or 10 mass% or more, 20 mass% or less (10 to 20 mass%), further preferably 16 mass% or more, 25 mass% or less (16 to 25 mass%), 16 mass% or more, 24 mass% or less (16 to 24 mass%), or 16 mass% or more, 20 mass% or less (16 to 20 mass%). When the inhibitor includes two or more types of inhibitors, the amount of the inhibitor may be, for example, the amount of one type of inhibitor, or the total amount of two or more types of inhibitor, but the latter is preferable.

When the inhibitor is a compound represented by the chemical formula (12) or (13), the amount of the compound represented by the chemical formula (12) or (13) to be blended may be, for example, more than 0% by mass relative to the entire mass of the flux, preferably 5% by mass or more, 25% by mass or less (5 to 25% by mass), 5% by mass or more, 24% by mass or less (5 to 24% by mass), or 5% by mass or more, 20% by mass or less (5 to 20% by mass), more preferably 10% by mass or more, 25% by mass or less (10 to 25% by mass), 10% by mass or more, 24% by mass or less (10 to 24% by mass), or 10% by mass or more, 20% by mass or less (10 to 20% by mass), further preferably 16% by mass or more, 25% by mass or less (16 to 25% by mass), 16% by mass or more, 24% by mass (16 to 24% by mass), or 16% by mass or more, or 20% by mass or less (16 to 20% by mass).

The flux of the present application may further comprise an amine. Examples of the amine include ethylamine, diethylamine, triethylamine, ethylenediamine, cyclohexylamine, 1, 3-diphenylguanidine, 1, 3-diorthoguanidine, 1-o-tolylbiguanide, imidazole, 2-ethylimidazole, 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1, 2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-methyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, and 1-benzyl-2-phenylimidazole.

The amount of the amine to be blended is not particularly limited, and is, for example, 0.1 mass% or more and 5 mass% or less (0.1 to 5 mass%), preferably 1 mass% or more and 5 mass% or less (1 to 5 mass%) with respect to the total amount of the flux.

The flux of the present application may further comprise an antioxidant. By the antioxidant, oxidation of the solder powder can be suppressed. Examples of the antioxidant include hindered phenol antioxidants, bisphenol antioxidants, and polymer antioxidants. The antioxidant may be used alone or in combination of two or more kinds.

The blending amount of the antioxidant is not particularly limited, and is, for example, 1% by mass or more and 10% by mass or less (1 to 10% by mass), preferably 1% by mass or more and 5% by mass or less (1 to 5% by mass) relative to the total amount of the flux.

The flux of the present application may further contain additives such as, for example, colorants, defoamers, surfactants, matting agents, and the like. The additive may be used alone or in combination of two or more kinds. The blending amount of the additive is not particularly limited, and is, for example, 0 mass% or more and 5 mass% or less (0 to 5 mass%) with respect to the total amount of the flux.

< solder paste >

The solder paste of the present application contains, as described above, a flux, which is the flux of the present application, and a solder powder. The solder paste of the present application is characterized by containing the flux of the present application, and other constitution and conditions are not particularly limited. The solder paste of the present application can suppress solder joint failure. The solder paste of the present application may be applied to the description of the inhibitor and the flux of the present application.

The solder powder may also be referred to as a metal powder, for example. The solder powder is not particularly limited, and for example, a solder containing no Pb is preferable, and Sn alone, or Sn-Ag type, sn—cu, sn-Ag-Cu, sn-Bi, sn-In, and the like, or a solder powder such as Sb, bi, in, cu, zn, as, ag, cd, fe, ni, co, au, ge, P is added to these alloys.

The particle size of the solder powder is not particularly limited, and may be in the range of 10 to 60 μm, for example, but may be larger or smaller. The amount of the solder powder to be blended with the flux of the present application can be appropriately set according to the particle size of the solder powder. The amount of the solder powder to be blended with the flux of the present application may be, for example, 8 to 15 mass% of the flux of the present application, and 85 to 92 mass% of the solder powder.

< electronic Circuit Board >

The electronic circuit board of the present application comprises a solder joint portion in which 2 members are joined by solder, and the solder joint portion contains the solder joint failure inhibitor of the present application. The electronic circuit board of the present application is characterized in that the solder joint portion contains the inhibitor of the present application, and other constitution and conditions are not particularly limited. The electronic circuit substrate of the present application may be applied with the description of the inhibitor, flux and solder paste of the present application.

The electronic circuit board may be a printed board or a flexible printed board. The use of the electronic circuit substrate is not particularly limited.

Examples of the 2 members include an electronic member, a combination of a wire thereof and a substrate wiring, a combination of substrate wirings, and the like. The electronic component is not particularly limited, and any electronic component mounted on an electronic circuit board can be exemplified.

< electronic apparatus >

The electronic device of the present application includes the electronic circuit board of the present application. The electronic device of the present application is characterized by comprising the electronic circuit board of the present application, and other configurations and conditions are not particularly limited. The electronic device of the present application may be used in the description of the inhibitor, flux, solder paste and electronic circuit board of the present application.

The electronic device is not particularly limited, and any electronic device including an electronic circuit board can be exemplified, and specific examples thereof include information devices such as a personal computer and a tablet terminal; electrified products such as televisions, refrigerators, washing machines and the like; air conditioning equipment such as air conditioning equipment.

< welding method >

The soldering method of the present application includes a bonding step of bonding the 1 st bonding object and the 2 nd bonding object in the presence of a solder joint failure inhibitor, which is the solder joint failure inhibitor of the present application. The welding method of the present application is characterized in that the joining step is performed in the presence of the inhibitor of the present application, and other steps and conditions are not particularly limited. The occurrence of solder joint failure can be suppressed by the soldering method of the present application. The soldering method of the present application may be applied to the description of the inhibitor, flux and solder paste of the present application.

The joining step may be carried out in a flow-type manner or in a reflow-type manner. The joining step may be performed, for example, using a solder to which (containing) the flux of the present application is added or the solder paste of the present application.

In the case of using the solder to which the flux of the present application is added, in the joining step, the 1 st joining object and the 2 nd joining object are melted by heating the 1 st joining object and the 2 nd joining object and the solder to which the flux is added, whereby the 1 st joining object and the 2 nd joining object can be joined by the solder.

In using the solder paste of the present application, the soldering method of the present application is implemented, for example, in the following manner. Before the joining step, the solder paste of the present application is transferred (adhered) to a joining portion joining the 1 st joining object and the 2 nd joining object in the 1 st joining object or the 2 nd joining object. Next, the 1 st bonding object or the 2 nd bonding object transferred with the solder paste of the present application is brought into contact with another bonding object. Thereafter, the solder paste of the present application is heated and melted, and the 1 st bonding object and the 2 nd bonding object are bonded by the solder paste of the present application.

[ example ]

The following describes embodiments of the present application. However, the present application is not limited to the following examples.

Example 1

It was confirmed that the occurrence of solder joint failure can be suppressed by the inhibitor of the present application.

< preparation of flux >

Table 1 below shows the compositions of examples 1 to 10 and comparative example 1. The respective materials in the amounts (mass%) shown in table 1 below were mixed and melted by heating to obtain evenly dispersed fluxes of examples 1 to 10 and comparative example 1. The inhibitor E of table 1 below uses a mixture of the compounds of the chemical formulas (12) and (13) belonging to the chemical formula (11).

[ Table 1]

< preparation of solder paste >

Solder paste was prepared using each flux having the composition shown in each of the examples and the comparative examples. Specifically, each of the solder pastes of examples 1 to 10 and comparative example 1 was prepared by mixing 12 mass% of each of the above-mentioned fluxes with 88 mass% of a solder powder (particle diameter: 20 to 38 μm) of Sn-3Ag-0.5Cu (melting point 217 ℃ C.) with respect to the whole solder paste.

< NWO evaluation experiment >

The solder pastes were evaluated for occurrence of defective joining (Non Wet Open: NWO). Specifically, the opening diameter was used on a substrate (Cu-OSP treated glass epoxy pad substrate): 0.30mm, mask thickness 0.12mm (120 μm), number of openings: 132 metal masks were printed with the solder pastes, and BGA with 0.5mm pitch was mounted with solder bumps. In the reflow oven, a heating rate from 25 ℃ (room temperature) to 130 ℃ was set to 3 ℃/sec, a heating rate from 130 to 190 ℃ was set to 1.0 ℃/sec, a peak temperature was set to 200 ℃, and the temperature was cooled after heating. After cooling, the substrate and the BGA are peeled off. Regarding the NWO evaluation after the peeling, a portion where the printed solder paste was adhered to the solder bump and the solder paste was not adhered to the substrate side was regarded as a portion where NWO was generated. Then, the number of sites where the NWO is generated is calculated, and if the number is 20 or less, it is determined that the bonding is good.

In general, since BGA is bent by heating, some parts tend to be separated from the substrate and BGA in reflow soldering. At this time, the solder paste rises from the substrate side to the BGA side, and the oxide film of the pad cannot be removed, resulting in poor bonding. That is, by this evaluation method, a potential site where NWO may occur can be predicted. In addition, when there are a plurality of potential portions, for example, even when the substrate and BGA are not separated or the printed portion is surrounded by a portion where no lift is provided, it is difficult to suppress bending of the BGA, and NWO occurs.

The NWO evaluation experiment described above is an example, and the conditions in the NWO evaluation experiment are not limited thereto. The heating conditions in NWO evaluation experiments may vary, for example, depending on the melting point of the solder powder and the temperature at which BGA warpage occurs. Specifically, the temperature rise rate from the room temperature to 130 ℃ can be set to, for example, 2.1 to 3.9 ℃/sec. The temperature rise rate of 130 to 190℃may be, for example, 0.7 to 1.3℃per second, and the peak temperature may be 160 to 240 ℃. It is also conceivable that the heating is performed by local heating without using a reflow oven, and that the temperature rise rate may be, for example, 3.5 to 6.0 ℃/sec when the local heating is performed.

< test for evaluating melting Property >

Solder paste was prepared using the fluxes of the respective examples and the comparative examples, and the opening diameter was used on a substrate (Cu-OSP treated glass epoxy substrate): 0.28mm, mask thickness 0.1mm, number of openings: 64 metal masks to print the solder paste. After the printing, the temperature rise rate of 50 to 170 ℃ is set to 4 ℃/sec, the temperature rise rate of 170 to 195 ℃ is set to about 0.2 ℃/sec, and the printing is performed for 118 sec, the peak temperature: 236.5 ℃,220 ℃ or more melting time: the reflow temperature profile of 43 seconds was used for atmospheric reflow to melt the solder alloy. Regarding the evaluation of the meltability, all of 64 points after printing were evaluated as "o", and even one point was not melted as "x".

The above-described melt property evaluation experiment is exemplified, and the conditions of the melt property evaluation experiment are not limited thereto. The heating conditions for the melting property evaluation experiment may be changed according to, for example, the melting point of the solder powder. Specifically, the temperature rise rate at 50 to 170℃may be set to, for example, 2.8 to 5.2℃per second. The temperature rise rate of 170 to 195℃may be, for example, 0.14 to 0.26℃per second, and the peak temperature may be 180 to 280 ℃. It is also conceivable that the heating is performed by local heating without using a reflow oven, and that the temperature rise rate may be, for example, 3.5 to 6.0 ℃/sec when the local heating is performed.

< test for evaluation of stability over time >

For each solder paste, manufactured by MALCOM corporation: PCU-205, according to the JISZ3284-3 spiral method, rotates at the number of revolutions: the viscosity was measured at 10rpm for 10 hours at 25℃in the atmosphere. Then, the viscosity after 10 hours was compared with the initial viscosity of the solder paste, and if it was 1.3 times or less, it showed sufficient stability with time, and if it was more than 1.3 times, it was evaluated as "o". The initial viscosity refers to the viscosity at the beginning of continuous stirring.

< test for evaluating Heat slump >

Each solder paste was measured according to JIS 3284-3. In addition, as for the metal mask, in fig. 6 of JISZ3284-3, a metal mask having a smaller aperture is used. The measurement result was evaluated as "O" at 0.4mm or less, and "X" at 0.5mm or more.

< test for evaluating tackiness >

Each solder paste was measured according to JIS 3284-3. When the average value of the force required to peel the probe was 1.1N or more, the measurement was evaluated as "o", and when the average value was less than 1.1N, the measurement was evaluated as "x".

Table 1 shows the evaluation results of the residue amount and reflux properties of the respective examples and the comparative examples. As is clear from table 1, the NWO evaluation value of the joint portion was 35 when the solder paste of comparative example 1 was used, whereas the NWO evaluation value of the joint portion was 20 or less when each of the solder pastes of examples 1 to 10 was used, and the occurrence of joint failure was suppressed. In addition, the NWO evaluation values of the solder pastes of examples 3 to 10 were 9 or less, and the occurrence of the poor joining was more effectively suppressed. Further, the NWO evaluation values of the solder pastes of examples 5 to 10 were 5 or less, and the occurrence of the joining failure was almost completely suppressed. From the results, it was found that the occurrence of the poor joining can be more effectively suppressed by adding the compound of the chemical formula (11) in an amount of 5 to 25 mass% relative to the total mass of the flux. Further, by adding the compound of the chemical formula (11) in an amount of 10 mass% or more or 11 mass% or more relative to the entire mass of the flux, the occurrence of the joining failure can be further effectively suppressed, and by adding 16 mass% or more, the occurrence of the joining failure can be almost completely suppressed. Further, the solder pastes of examples 1 to 9 were better in meltability (reflow property) than the solder paste of example 10. Therefore, from the results, it was found that by adding 24 mass% or less, specifically, 5 to 24 mass% of the compound of the chemical formula (11) relative to the entire mass of the flux, the occurrence of poor joining can be more effectively suppressed, and more excellent meltability can be obtained.

The present application is described above with reference to the embodiments and examples, but the present application is not limited to the embodiments and examples. The constitution and details of the present application may be variously changed within the scope of the present application as will be understood by those skilled in the art.

The present application claims priority based on japanese patent application 2020-61211 filed on 3/30/2020, the disclosure of which is incorporated herein.

< additional notes >

Some or all of the above embodiments and examples may be described in the form of the following additional notes, but are not limited thereto.

(additionally, 1)

A solder joint failure inhibitor comprising the compound represented by the formula (11),

in the chemical formula (11) described above,

R ¹¹ and R is ¹² Each of which is independently a carboxyl group,

(additionally remembered 2)

The solder joint failure inhibitor according to supplementary note 1, wherein the compound represented by the chemical formula (11) is a compound represented by the chemical formula (12).

(additionally, the recording 3)

The solder joint failure inhibitor according to supplementary note 1, wherein the compound represented by the chemical formula (11) is a compound represented by the chemical formula (13).

(additionally remembered 4)

A flux composition comprising a metal oxide and a metal oxide,

comprises a matrix resin, an activator, a thixotropic agent, a solvent and a solder poor bonding inhibitor,

the solder joint failure inhibitor is the solder joint failure inhibitor according to any one of supplementary notes 1 to 3.

(additionally noted 5)

The flux according to supplementary note 4, wherein the amount of the inhibitor of solder joint failure to be blended is 5 mass% or more and 25 mass% or less with respect to the entire mass of the flux.

(additionally described 6)

The flux according to supplementary note 4, wherein the amount of the inhibitor of solder joint failure to be blended is 10 mass% or more and 25 mass% or less with respect to the entire mass of the flux.

(additionally noted 7)

The flux of any one of supplementary notes 4 to 6, further comprising an amine.

(additionally noted 8)

The flux of appendix 7, wherein the amine is selected from imidazoles.

(additionally, the mark 9)

The flux of any one of supplementary notes 4 to 8, further comprising an antioxidant.

(additionally noted 10)

A solder paste composition comprising a solder paste,

comprising a flux and a solder powder,

the flux is the flux of any one of supplementary notes 4 to 9.

Industrial applicability

As described above, according to the present application, occurrence of solder joint failure can be suppressed. Therefore, the present application can be suitably used for a semiconductor substrate such as a BGA.

Claims

1. A flux composition comprising a metal oxide and a metal oxide,

the solder joint failure inhibitor is a solder joint failure inhibitor containing a compound represented by the following chemical formula (11), and the amount of the solder joint failure inhibitor to be blended is 5 mass% or more and 25 mass% or less relative to the entire mass of the flux:

in the chemical formula (11) described above,

R ⁹ is a saturated straight-chain alkyl group having 4 to 8 carbon atoms,

R ¹⁰ is a saturated straight-chain alkyl group having 5 to 9 carbon atoms,

R ¹¹ and R is ¹² Each of which is independently a carboxyl group,

2. The flux according to claim 1, wherein the compound represented by the formula (11) is a compound represented by the following formula (12)

3. The flux according to claim 1, wherein the compound represented by the formula (11) is a compound represented by the following formula (13)

4. The flux according to any one of claims 1 to 3, wherein the amount of the inhibitor of solder joint failure to be blended is 10 mass% or more and 25 mass% or less with respect to the entire mass of the flux.

5. A flux according to any one of claims 1 to 3, further comprising an amine.

6. The flux of claim 5 wherein the amine is selected from imidazoles.

7. A flux according to any one of claims 1 to 3, further comprising an antioxidant.

8. A solder paste, wherein

Comprising a flux and a solder powder,

the flux is the flux as defined in any one of claims 1 to 3.