TW202106888A - Solder paste and flux for solder paste - Google Patents

Abstract

The present invention adopts a solder paste containing a specific solder powder and a flux. The solder powder contains a solder alloy which has an alloy composition including: As: 10 mass ppm or more and less than 40 mass ppm, and at least one of Bi: 0 to 25,000 mass ppm and Pb: 0 to 8,000 mass ppm, with the balance of Sn, and satisfies formulas (1) and (2). 300 ≤ 3As+Bi+Pb (1) 0 < 2.3*10<SP>-4</SP>*Bi+8.2*10<SP>-4</SP>*Pb ≤ 7 (2) In the formulas (1) and (2), As, Bi and Pb each represent the content (mass ppm) in the alloy composition.

Description

Solder paste and flux for solder paste

The present invention relates to solder paste and flux for solder paste. This application claims priority based on Japanese Patent Application No. 2019-098934 filed in Japan on May 27, 2019, and its content is cited here.

In recent years, electronic devices with solder joints, such as CPUs (Central Processing Units), are required to be miniaturized and high-performance. Along with this, it is necessary to achieve miniaturization of the electrodes of printed circuit boards and electronic devices. Since the electronic device is connected to the printed circuit board via the electrode, the size of the electrode has been reduced, and the solder joint connecting the two has also become smaller.

In order to connect the electronic device and the printed circuit board via such fine electrodes, solder paste is generally used.

The solder paste is supplied to the electrodes of the printed circuit board by printing or the like. The printing of solder paste is done by placing a metal mask with an opening on the printed circuit board, pressing the squeegee against the metal mask and moving it to apply the solder paste from the opening of the metal mask at once. On the electrodes on the printed circuit board.

In addition, when the solder paste is purchased, it is usually not possible to use the full amount in one printing. In this way, the solder paste must maintain the proper viscosity at the time of manufacture in a way that does not impair the printing performance on the substrate.

However, with the progress of miniaturization of electrodes in recent years, the printing area of the solder paste has also been narrowed, and the time until the purchased solder paste has been used up has also become longer. Solder paste is a mixture of solder powder and flux. If the storage period covers a long period of time, the viscosity of the solder paste will increase due to the difference in storage conditions, and the printing performance at the time of purchase may not be exhibited.

Therefore, for example, Patent Document 1 discloses a solder alloy that contains Sn and one selected from the group consisting of Ag, Bi, Sb, Zn, In, and Cu in order to suppress changes in the solder paste over time. Or two or more, and contain a predetermined amount of As. In the same document, it is shown that the viscosity after 2 weeks at 25°C is less than 140% compared to the viscosity at the time of production.

On the other hand, the flux used in soldering (also known as soldering) has the ability to chemically remove the metal oxides present on the solder and the metal surface of the joining object to be soldered, so that the metal elements can be The efficiency of moving on the border between the two. Therefore, by soldering using a flux, an intermetallic compound can be formed between the solder and the metal surface of the joining object, and a strong joint can be obtained.

In the solder paste containing the soldering flux and solder powder, the thixotropic agent (also called thixotropic agent) contained in the flux is used to impart thixotropic viscosity reduction. The thixotropic viscosity-reducing agent builds a network in the flux to give the thixotropic viscosity-reducing property.

[Prior Technical Literature]

[Patent Literature]

[Patent Document 1] JP 2015-98052 A

As described above, the invention described in Patent Document 1 is a solder alloy that can optionally contain 6 types of elements in addition to Sn and As. In addition, the same literature shows that when the As content is large, the melting property is poor.

Here, the meltability evaluated in Patent Document 1 can be considered to be equivalent to the wettability of molten solder. The melting property disclosed in the same document is observed by observing the appearance of the melt with a microscope, and evaluated by the presence or absence of solder powder that is not completely melted. This is because the higher the wettability of the molten solder, the more difficult it is for the incompletely molten solder powder to remain.

Generally speaking, in order to improve the wettability of molten solder, a highly active flux must be used. In the flux described in Patent Document 1, in order to suppress the deterioration of wettability caused by As, a highly active flux can be considered. However, when a highly active flux is used, the viscosity of the paste increases due to the progress of the reaction between the solder alloy and the active agent. In addition, in view of the description of Patent Document 1, in order to suppress the increase in viscosity, the As content must be increased. In order for the solder paste described in Patent Document 1 to exhibit a lower rate of increase in viscosity and excellent wettability, it is necessary to continuously increase the activity of the flux and the As content, which leads to a vicious circle.

Recently, solder paste systems are required to maintain stable performance over a long period of time without being affected by the use environment or storage environment. In addition, due to the miniaturization of solder joints, higher wettability is also required. When it is desired to use the solder paste described in Patent Document 1 to meet recent demands, a vicious circle cannot be avoided as described above.

Furthermore, in order to join fine electrodes, the mechanical properties of the solder joint must be improved. Due to different elements, sometimes when the content increases, the liquidus temperature rises and the liquidus temperature and the solidus temperature expand, and segregation occurs during solidification to form an uneven alloy structure. When the solder alloy has this alloy structure, the mechanical properties such as the tensile strength of the solder joint deteriorate, and it is likely to be broken due to external stress. This problem has become remarkable with the miniaturization of electrodes in recent years.

In addition, in the solder paste, depending on its use conditions and applications, it is required to increase the wetting speed of the solder, inhibit the corrosion of the metal surface of the joint object (such as copper plate), improve the printability, and suppress the voids. characteristic.

The present invention was made in order to solve the above-mentioned problems, and its purpose is to provide a method that does not easily cause changes over time (that is, changes over time) such as a rise in viscosity, has excellent wettability, and has high mechanical properties. A solder paste that improves various characteristics.

While improving the suppression of solder paste changes over time and excellent wettability at the same time, it is necessary to avoid the vicious circle caused by the use of flux with high activity and the increase in As content. The inventors of the present invention focused on the alloy composition of the solder powder, and conducted intensive studies in order to simultaneously achieve suppression of changes in solder paste over time and excellent wettability.

First, the inventors used the Sn, SnCu, and SnAgCu solder alloys previously used as solder alloys as the basic composition to discuss the solder powder containing As in this basic composition. Then, in the case of using this solder powder, the reason for suppressing the change of the solder paste over time is discussed, and the As content is discussed.

The reason why the viscosity of the solder paste increases with the passage of time can be considered because the solder powder reacts with the flux. Then compare the results of Example 4 and Comparative Example 2 in Table 1 of Patent Document 1. When the As content exceeds 100 mass ppm, the viscosity increase rate is low. In view of these results, focusing on the effect of suppressing the change of the solder paste over time (hereinafter referred to as the "thickness-increasing suppression effect" as appropriate), it is conceivable that the As content can be further increased. However, when the As content is increased, the viscosity-increasing inhibitory effect increases slightly along with the As content, but the viscosity-increasing inhibitory effect corresponding to the increase in As content is not obtained. It can be considered that the amount of As concentrated on the surface of the solder alloy still has its limit. Even if it contains more than a predetermined amount of As, the increase in the amount of As inside the solder alloy makes it difficult to exert the effect of suppressing the increase in viscosity. In addition, it can be confirmed that when the As content is too large, the wettability of the solder alloy deteriorates.

Therefore, the inventors thought that after extending the range of As content to a range where the As content was small and the effect of inhibiting the increase in viscosity was not exhibited, it was necessary to add elements that exhibit the effect of inhibiting the increase in viscosity in addition to As, and then explored various element. As a result, it was accidentally discovered that Bi and Pb exert the same effects as As. Although the reason for this has not been determined, it can be estimated as follows.

The effect of suppressing thickening is exerted by suppressing the reaction with the flux. Therefore, elements with low reactivity with the flux include elements with a low ionization tendency. Generally speaking, the ionization of an alloy is considered based on the ionization tendency of the alloy composition, that is, the standard electrode potential. For example, SnAg alloys containing Ag, which has a higher potential than Sn, are more difficult to ionize than Sn. Therefore, an alloy system containing an element having a higher potential than Sn is difficult to ionize, so it can be presumed that the solder paste has a high effect of suppressing viscosity increase.

Here, in Patent Document 1, in addition to Sn, Ag, Cu, Bi, Sb, Zn, and In are disclosed as equivalent elements. In terms of ionization tendency, Zn is the element with the lowest potential among these elements. , And it is a lower potential element than Sn. That is, Patent Document 1 describes that even if Zn, which is an element with the lowest potential, is added, the effect of suppressing viscosity increase can be obtained. Therefore, it can be considered that a solder alloy containing an element selected according to the ionization tendency can obtain an effect of suppressing viscosity increase at least as compared with the solder alloy described in Patent Document 1. In addition, as described above, when the As content increases, the wettability deteriorates.

The inventors discussed in detail Bi and Pb, which exert the effect of suppressing viscosity increase. Since Bi and Pb lower the liquidus temperature of the solder alloy, when the heating temperature of the solder alloy is constant, the wettability of the solder alloy is improved. However, since the difference in its content causes the solidus temperature to decrease significantly, the ΔT of the temperature difference between the liquidus temperature and the solidus temperature is excessively expanded. When ΔT expands excessively, segregation occurs during solidification, resulting in a decrease in mechanical properties such as mechanical strength. It has also been found that the phenomenon of △T expansion appears significantly when Bi and Pb are added at the same time, so strict management must be carried out.

In Sn, SnCu solder alloys, and SnAgCu solder alloys, in order to achieve excellent results for all the characteristics of adhesion suppression effect, excellent wettability, and narrowing of △T, it can be considered that the contents of As, Bi, and Pb are not individually managed. , But must manage the content of these elements as a whole. Therefore, the present inventors conducted various studies on the content of these three elements, and as a result, accidentally discovered that when the content of each element satisfies the predetermined relational expression within a predetermined quantitative range, the viscosity increase inhibitory effect and the lubrication All the characteristics of wettability and narrowing of ΔT showed excellent results.

Furthermore, it has been discovered that by selecting the components of the flux used in combination with the above-mentioned solder alloys, such as resin components, active components, or types of solvents, the wetting speed of the solder can be increased, and the metal surface of the joining object can be improved. (E.g. copper plate) corrosion inhibition, printability improvement, void suppression and other various characteristics.

The present invention derived from these findings is as follows.

[1] A solder paste containing solder powder and flux, the aforementioned solder powder containing a solder alloy, the solder alloy having: As: 10 mass ppm or more and less than 40 mass ppm, and Bi: 0 to 25,000 mass ppm and Pb: at least one of 0 to 8000 ppm by mass, and the remainder is an alloy composition composed of Sn, and satisfies the following equations (1) and (2).

300≦3As+Bi+Pb (1)

0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2)

In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition.

[2] A solder paste containing solder powder and flux, the aforementioned solder powder containing a solder alloy having: As: 10 mass ppm or more and less than 40 mass ppm, and Bi: more than 0 mass ppm At least one of 25,000 ppm by mass or less and Pb: more than 0 ppm by mass and 8,000 ppm by mass or less, and the remainder is an alloy composition composed of Sn, and satisfies the following equations (1) and (2).

300≦3As+Bi+Pb (1)

0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2)

In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition.

[3] A solder paste containing solder powder and flux, the aforementioned solder powder containing a solder alloy, the solder alloy having: As: 10 mass ppm or more and less than 40 mass ppm, and Bi: 50 to 25,000 mass ppm and Pb: more than 0 mass ppm and at least one of 8000 mass ppm or less, and the remainder is an alloy composition composed of Sn, and satisfies the following formulas (1) and (2).

300≦3As+Bi+Pb (1)

0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2)

In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition.

[4] A solder paste containing solder powder and flux, the aforementioned solder powder containing a solder alloy having: As: 10 mass ppm or more and less than 40 mass ppm, and Bi: more than 0 mass ppm And it is 25000 mass ppm or less and at least one of Pb: 50 to 8000 mass ppm, and the remainder is an alloy composition composed of Sn, and satisfies the following formulas (1) and (2).

300≦3As+Bi+Pb (1)

0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2)

In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition.

[5] A solder paste containing solder powder and flux, the aforementioned solder powder containing a solder alloy, the solder alloy having: As: 10 mass ppm or more and less than 40 mass ppm, and Bi: 50 to 25,000 mass ppm and Pb: at least one of 50 to 8000 ppm by mass, and the remainder is an alloy composition composed of Sn, and satisfies the following equations (1) and (2).

300≦3As+Bi+Pb (1)

0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2)

In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition.

[6] The solder paste according to any one of [1] to [5] above, wherein the flux contains a resin component, an active component, and a solvent.

[7] The solder paste according to the above [6], wherein the flux contains a hindered phenol compound.

[8] The solder paste described in [6] above, wherein the soldering flux contains a metal deactivator which is a nitrogen compound.

[9] The solder paste described in [6] above, wherein the soldering flux contains acid-modified rosin.

[10] The solder paste according to the above [6], wherein the soldering flux contains an acrylic resin.

[11] The solder paste according to the above [6], wherein the flux system contains: dimer acids selected from reactants belonging to monocarboxylic acids and dimers, and hydrogen is added to the dimer acid The obtained hydrogenated dimer acid, the trimer acid that is a reactant of monocarboxylic acid and is a trimer, and the hydrogenated trimer acid obtained by adding hydrogen to the trimer acid is one of the group consisting of At least one organic acid.

[12] The solder paste described in [6] above, wherein the flux contains a compound represented by the following general formula (1),

In the formula (1), R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[13] The solder paste described in [6] above, wherein the soldering flux contains Azoles.

[14] The solder paste described in [6] above, wherein the flux contains an aromatic guanidine compound.

[15] The solder paste according to the above [6], wherein the soldering flux contains an amide-based thixotropic agent which is an amide compound.

[16] The solder paste according to the above [6], wherein the flux contains a sorbitol-based thixotropic agent which is a Sorbitol compound.

[17] The solder paste according to the above [6], wherein the flux includes a glycol solvent and an organic acid ester.

[18] The solder paste according to the above [6], wherein the flux includes a glycol solvent and a monohydric alcohol having 16 to 18 carbon atoms.

[19] The solder paste described in any one of [1] to [18] above, which further contains zirconia powder.

[20] A flux for solder paste, which is a flux for solder paste used in solder paste, said solder paste contains solder powder containing a solder alloy, and the solder alloy has: As: 10 mass ppm or more and less than 40 mass ppm, and at least one of Bi: 0 to 25,000 mass ppm and Pb: 0 to 8,000 mass ppm, and the remainder is an alloy composition composed of Sn, and satisfies the following formulas (1) and (2) .

300≦3As+Bi+Pb (1)

0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2)

In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition.

[21] A flux for solder paste, which is a flux for solder paste used in solder paste, said solder paste contains solder powder containing a solder alloy, and the solder alloy has: As: 10 mass ppm or more and less than 40 mass ppm, and Bi: more than 0 mass ppm and less than 25000 mass ppm and Pb: more than 0 mass ppm and at least one of 8000 mass ppm or less, and the remainder is an alloy composition composed of Sn, and satisfies the following State (1) and (2).

300≦3As+Bi+Pb (1)

0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2)

In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition.

According to the present invention, it is possible to provide a solder paste and flux for solder paste that are less likely to cause changes in viscosity over time, such as an increase in viscosity, are excellent in wettability, have high mechanical properties, and can improve various properties.

The following describes the present invention in detail.

In this manual, "ppm" related to solder alloy composition is "mass ppm" unless otherwise specified. "%" is "mass%" when it is not specified.

<Solder Paste>

The solder paste of this embodiment contains specific solder powder and flux.

"Solder Powder"

The solder powder used in the solder paste of this embodiment contains a solder alloy. The solder alloy has: As: 10 mass ppm or more and less than 40 mass ppm, and Bi: 0 to 25,000 mass ppm and Pb: 0 to 8000 At least one of the mass ppm, and the remainder is an alloy composition composed of Sn, and satisfies the following equations (1) and (2).

300≦3As+Bi+Pb (1)

0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2)

In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition.

1. Alloy composition

(1) As: 10 mass ppm or more and less than 40 mass ppm

As is an element that can suppress the viscosity of the solder paste from changing over time.

Since As has low reactivity with flux and is an element with a high potential relative to Sn, it is speculated that it can exert a viscosity-increasing inhibitory effect. When As is less than 10 mass ppm, the effect of suppressing thickening cannot be sufficiently exhibited. The lower limit of the As content is 10 mass ppm or more, preferably 14 mass ppm or more.

On the other hand, when there is too much As, the wettability of the solder alloy deteriorates due to the activity of the flux. The upper limit of the As content is less than 40 mass ppm, preferably less than 38 mass ppm, particularly preferably less than 25 mass ppm, more preferably less than 24 mass ppm, and particularly preferably less than 18 mass ppm.

(2) Bi: 0 to 25000 mass ppm and Pb: 0 to 8000 mass ppm

Bi and Pb are elements that have low reactivity with flux and exhibit an effect of suppressing viscosity increase. In addition, these elements lower the liquidus temperature of the solder alloy and lower the viscosity of the molten solder, so they are elements that can suppress the deterioration of the wettability caused by As. If at least one of Bi and Pb is present, the deterioration of wettability due to As can be suppressed.

When the solder alloy of the present invention contains Bi, the lower limit of the Bi content is 0 mass ppm or more, may exceed 0 mass ppm, or may be 50 mass ppm or more. The Bi content is preferably 123 mass ppm or more, particularly preferably 150 mass ppm or more, and more preferably 246 mass ppm or more.

When the solder alloy of the present invention contains Pb, the lower limit of the Pb content is 0 mass ppm or more, may exceed 0 mass ppm, or may be 50 mass ppm or more. The Pb content is preferably 123 mass ppm or more, particularly preferably 246 mass ppm or more.

On the other hand, when the content of these elements is too large, the solidus temperature is significantly lowered, so the ΔT of the temperature difference between the liquidus temperature and the solidus temperature is excessively expanded. When ΔT expands excessively, a crystal phase with a high melting point with a small Bi or Pb content during the solidification of the molten solder precipitates, and the liquid phase Bi or Pb is concentrated. Then, when the temperature of the molten solder is further reduced, a crystal phase with a high Bi or Pb concentration and a low melting point segregates. Therefore, the mechanical strength and the like of the solder alloy are deteriorated. In particular, the crystalline phase with a high Bi concentration is hard and brittle, and when segregation occurs in the solder alloy, the mechanical strength and the like are significantly reduced.

From this point of view, when the solder alloy of the present invention contains Bi, the upper limit of the Bi content is 25,000 mass ppm or less, preferably 10,000 mass ppm or less, particularly preferably 1,000 mass ppm or less, and more preferably 300 mass ppm or less .

In the case where the solder alloy of the present invention contains Pb, the upper limit of the Pb content is 8000 mass ppm or less, preferably 5100 mass ppm or less, particularly preferably 1000 mass ppm or less, and more preferably 300 mass ppm or less.

(3)(1)

The solder alloy of the present invention must satisfy the following formula (1).

300≦3As+Bi+Pb (1)

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

As, Bi, and Pb are all elements exhibiting a thickening inhibitory effect, and the total of these must be 300 mass ppm or more.

In the formula (1), the As content is set to 3 times, because when at least one of Bi and Pb is contained, the As content is less than these contents. In addition, As is higher than Bi or Pb. Because of the high viscosity suppression effect.

(1) When the formula is less than 300, the viscosity increase suppression effect is not sufficiently exhibited. The lower limit of the formula (1) is 300 or more, preferably 480 or more, particularly preferably 496 or more, more preferably 504 or more, particularly preferably 522 or more, and most preferably 564 or more. On the other hand, the upper limit of formula (1) is not particularly limited from the viewpoint of the thickening suppression effect, but from the viewpoint of setting ΔT in a suitable range, it is preferably 25114 or less, and particularly preferably 25042 or less , More preferably 15214 or less, particularly preferably 15172 or less, most preferably 15142 or less.

Since the upper limit of the As content is less than 40 mass ppm, the solder alloy of the present invention contains at least one of Bi and Pb in a total of more than 180 mass ppm. In this way, although the As content is small in the present invention, the Bi and Pb content is set to be large, and a sufficient thickening suppression effect is exhibited. In the absence of Bi and Pb, the viscosity of the solder paste will increase immediately.

The upper limit is appropriately selected from the above-mentioned preferable aspects, and it is the following formula (1a).

300≦3As+Bi+Pb≦25114 (1a)

In the above formula (1a), As, Bi, and Pb each represent the content (mass ppm) in the alloy composition.

(4)(2)

The solder alloy of the present invention must satisfy the following formula (2).

0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2)

In the above formula (2), Bi and Pb each represent the content (mass ppm) in the alloy composition.

Bi and Pb suppress the deterioration of wettability caused by the inclusion of As, but when the content is too large, ΔT will increase, so strict management is required. Especially in an alloy composition containing both Bi and Pb, ΔT tends to increase. In the present invention, by prescribing the sum of the values obtained by multiplying the contents of Bi and Pb by a predetermined coefficient, the increase in ΔT can be suppressed. In the formula (2), the coefficient of Pb is greater than the coefficient of Bi. This is because Pb has a greater effect on ΔT than Bi, and only a small increase in content will cause ΔT to rise sharply.

(2) The solder alloy system of formula 0 does not contain both Bi and Pb, and cannot suppress the deterioration of wettability due to the inclusion of As.

The lower limit of the formula (2) is more than 0, preferably 0.06 or more, particularly preferably 0.13 or more, more preferably 0.20 or more, particularly preferably 0.28 or more, and most preferably 0.32 or more.

On the other hand, when the formula (2) exceeds 7, the temperature range of ΔT expands excessively, and during the solidification of the molten solder, crystal phases with a high concentration of Bi or Pb segregate, resulting in deterioration of mechanical strength and the like.

(2) The upper limit of the formula is 7 or less, preferably 6.56 or less, particularly preferably 6.48 or less, more preferably 5.75 or less, more preferably 1.05 or less, particularly preferably 0.89 or less, and most preferably 0.48 or less.

The upper limit and the lower limit are appropriately selected from the above-mentioned preferable aspects, and it is the following formula (2a).

0.06≦2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦6.56 (2a)

In the above formula (2a), Bi and Pb each represent the content (mass ppm) in the alloy composition.

(5) Ni: 0 to 600 mass ppm, Fe: 0 to 100 mass ppm

Fe and Ni are arbitrary elements that can inhibit the growth of intermetallic compounds.

In the case where the solder alloy of the present invention is joined to a Cu electrode or contains Cu as described later, Ni can convert the Cu ₆ Sn ₅ layer formed on the joint interface into a (Cu, Ni) ₆ Sn ₅ layer, and Thin the film thickness of the intermetallic compound layer. In addition, Fe can promote the formation of crystal nuclei during the solidification of molten solder and inhibit the growth of intermetallic compound phases such as _{Cu 6} Sn ₅ , Cu ₃ Sn, and Ag _{3 Sn.} If the content of these elements is within a predetermined range, the liquidus temperature will not rise excessively, and ΔT will be within the allowable range and high mechanical properties can be maintained.

When the solder alloy of the present invention contains Ni, the upper limit of the Ni content is preferably 600 mass ppm or less, particularly preferably 500 mass ppm or less, more preferably 100 mass ppm or less, and particularly preferably 50 mass ppm or less.

In the case where the solder alloy of the present invention contains Fe, the upper limit of the Fe content is preferably 100 mass ppm or less, particularly preferably 80 mass ppm or less, and more preferably 50 mass ppm or less.

The lower limit of the content of Ni and Fe is not particularly limited. In order to fully exhibit the effect of suppressing the growth of intermetallic compounds, the lower limit of the content of Ni is preferably 10 mass ppm or more, and particularly preferably 40 mass ppm or more. The lower limit of the Fe content is preferably 10 mass ppm or more, and particularly preferably 20 mass ppm or more.

(6) In: 0 to 1200 mass ppm

In is a solid solution strengthening element body of Sn, so it is an arbitrary element that can maintain high mechanical properties. If the In content is within the predetermined range, ΔT is within the allowable range and high mechanical properties can be maintained.

In the case where the solder alloy of the present invention contains In, the upper limit of the In content is preferably 1200 ppm by mass or less, particularly preferably 100 ppm by mass or less.

The lower limit of the In content is not particularly limited. In order to sufficiently form a solid solution, it is preferably 20 mass ppm or more, particularly preferably 30 mass ppm or more, and more preferably 50 mass ppm or more.

(7) At least two of Ni: 0 to 600 mass ppm, Fe: 0 to 100 mass ppm, and In: 0 to 1200 mass ppm

If the contents of Ni, Fe, and In are within a predetermined range, ΔT is easily within an allowable range and high mechanical properties can be maintained. In the present invention, at least two or more of these may be contained within a predetermined range, or three at the same time.

(8) Ni: 0 to 600 mass ppm and Fe: 0 to 100 mass ppm, and (3) formula

The solder alloy of the present invention preferably contains a predetermined amount of Ni and Fe, and satisfies the following formula (3).

0≦Ni/Fe≦50 (3)

(3) In the formula, Ni and Fe each represent the content (mass ppm) in the alloy composition.

Fe and Ni can inhibit the growth of intermetallic compounds, but Ni can inhibit the growth of the intermetallic compound layer at the joint interface, and Fe can inhibit the growth of the intermetallic compound phase in the solder alloy. In order to suppress the growth of intermetallic compounds in the entire solder joint, the content of the two elements is preferably balanced to a certain degree.

The solder alloy of the present invention preferably satisfies formula (3) in addition to containing a predetermined amount of Ni and Fe. In order to exert this effect, the lower limit of the formula (3) is preferably 0 or more, particularly preferably 0.1 or more, more preferably 2 or more, and particularly preferably 7.5 or more. The upper limit of the formula (3) is preferably 50 or less, particularly preferably 10 or less, and more preferably 8.0 or less.

In order to suppress the growth of intermetallic compounds and keep the liquidus temperature within the allowable range while maintaining high mechanical properties, the solder alloy of the present invention preferably satisfies the following formula (4) more.

0≦Ni+Fe≦680 (4)

(4) In the formula, Ni and Fe each represent the content (mass ppm) in the alloy composition.

In order to suppress the growth of intermetallic compounds, the lower limit of the formula (4) is preferably 0 mass ppm or more, particularly preferably 20 mass ppm or more, more preferably 40 mass ppm or more, particularly preferably 50 mass ppm or more, and most preferably 60 mass ppm. Mass ppm or more.

In addition, in order not to increase the liquidus temperature excessively, the upper limit of the formula (4) is preferably 680 mass ppm or less, particularly preferably 500 mass ppm or less, more preferably 200 mass ppm or less, particularly preferably 150 mass ppm or less , The best is 110 mass ppm or less.

(9) At least one of Ag: 0 to 4% by mass and Cu: 0 to 0.9% by mass

_{Ag is an arbitrary element that forms Ag 3} Sn at the crystal interface and can improve the mechanical strength of the solder alloy. In addition, Ag is an element that tends to ionize and has a higher potential than Sn. Coexistence of As, Pb, and Bi can contribute to these thickening inhibitory effects.

The lower limit of the Ag content is preferably 0% by mass or more, more preferably 0.5% by mass or more, and more preferably 1.0% by mass or more. The upper limit of the Ag content is preferably 4% by mass or less, particularly preferably 3.5% by mass or less, and more preferably 3.0% by mass or less.

Cu is an arbitrary element that can improve the bonding strength of solder joints. In addition, Cu is an element that tends to ionize and has a higher potential than Sn. Coexistence of As, Pb, and Bi can contribute to these thickening inhibitory effects.

The lower limit of the Cu content is preferably 0% by mass or more, more preferably 0.1% by mass or more, and more preferably 0.2% by mass or more. The upper limit of the Cu content is preferably 0.9% by mass or less, more preferably 0.8% by mass or less, and more preferably 0.7% by mass or less.

(10) Remaining part: Sn

The remainder of the solder alloy of the present invention is Sn. In addition to the aforementioned elements, unavoidable impurities may be contained. Even if it contains unavoidable impurities, it will not affect the aforementioned effects. In addition, as described later, even if an element not contained in the present invention is contained as an inevitable impurity, the aforementioned effect will not be affected.

2. Solder powder

The solder powder of the present invention is used in the solder paste described later, and is preferably a spherical powder. By becoming spherical powder, the fluidity of the solder alloy can be improved. According to the classification of powder size in JIS Z 3284-1:2014 (Table 2), the solder powder of the present invention preferably satisfies the size (particle size distribution) that meets the signs 1 to 8, and more preferably satisfies the size (particle size distribution) that meets the signs 4 to 8. The size (particle size distribution) is more preferably a size (particle size distribution) that satisfies marks 5 to 8. When the particle size satisfies this condition, the surface area of the powder will not be too large to suppress the increase in viscosity. In addition, the aggregation of fine powder may be suppressed to suppress the increase in viscosity. Therefore, it is possible to weld finer parts.

The sphericity of the solder powder is preferably 0.90 or more, more preferably 0.95 or more, and most preferably 0.99 or more. In the present invention, the sphericity of the spherical powder is measured using a CNC image measurement system (ULTRA QUICK VISION ULTRA QV350-PRO measurement device manufactured by Mitutoyo) using the minimum zone center method (MZC method).

In the present invention, the so-called true sphericity means the deviation from the true ball. For example, it is the arithmetic mean value calculated when the diameter of each ball of 500 balls is divided by the major diameter. The closer the value is to the upper limit of 1.00, it means The closer it is to the real ball.

"Flux"

The flux used in the solder paste of this embodiment includes, for example, one containing a resin component, an active component, and a solvent.

Examples of resin components include rosin resins, acrylic resins, urethane resins, polyester resins, phenoxy resins, vinyl ether resins, terpene resins, modified terpene resins (such as aromatic Modified terpene resin, hydrogenated terpene resin, hydrogenated aromatic modified terpene resin, etc.), terpene phenol resin, modified terpene phenol resin (such as hydrogenated terpene phenol resin, etc.), styrene resin, modified styrene resin (such as styrene Acrylic resin, styrene maleic acid resin, etc.), xylene resin, modified xylene resin (e.g. phenol modified xylene resin, alkylphenol modified xylene resin, phenol modified resol xylene Resin, polyol modified xylene resin, polyoxyethylene addition xylene resin, etc.).

The term "acrylic resin" here means a concept that includes methacrylic resins and other derivatives of these esters in addition to acrylic resins.

Examples of the rosin-based resin include raw material rosins such as gum rosin, wood rosin, and tall oil rosin, and derivatives derived from the raw material rosin. Examples of the derivatives include: refined rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, and α, β unsaturated carboxylic acid modification Rosin (acrylated rosin, maleated rosin, fumarated rosin, etc.), as well as refined products, hydrogenated products and disproportions of the polymerized rosin, and refined products and hydrogenated products of the α, β unsaturated carboxylic acid modified products And disproportionate.

Examples of active ingredients include organic acids, amines, amine hydrohalides, organic halogen compounds, thixotropic agents, metal deactivators, surfactants, antioxidants, silane coupling agents, colorants, and the like.

Examples of organic acids include glutaric acid, adipic acid, azelaic acid, eicosandioic acid, citric acid, glycolic acid, succinic acid, salicylic acid, diglycolic acid, dipyridine-2-carboxylic acid, Dibutylaniline diglycolic acid, suberic acid, sebacic acid, thioglycolic acid, terephthalic acid, dodecanedioic acid, p-hydroxyphenylacetic acid, pyridine-2-carboxylic acid, phenylsuccinic acid , Phthalic acid, fumaric acid, maleic acid, malonic acid, lauric acid, benzoic acid, tartaric acid, tris(2-carboxyethyl) isocyanurate, glycine, 1 ,3-Cyclohexanedicarboxylic acid, 2,2-bis(hydroxymethyl)propionic acid, 2,2-bis(hydroxymethyl)butanoic acid, 2,3-dihydroxybenzoic acid, 2,4-di Ethylglutaric acid, 2-quinoline carboxylic acid, 3-hydroxybenzoic acid, malic acid, p-anisic acid, stearic acid, 12-hydroxystearic acid, oleic acid, linoleic acid, linoleic acid Linolenic acid, dimer acid, trimer acid, hydrogenated dimer acid in which hydrogen is added to the hydride of dimer acid, hydrogenated trimerization of hydride in which hydrogen is added to trimer acid Material acid and so on.

Examples of the amine include ethylamine, triethylamine, ethylenediamine, triethylenetetramine, 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole , 2-Ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-benzene Ylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1- Cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole salt trimellitate, 1-cyanoethyl-2-phenylimidazole salt trimellitate, 2,4-Diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamine 6-[2'-Undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methyl Imidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine Cyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxy Methyl imidazole, 2,3-dihydro-1H-pyrrole [1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzimidazole chloride, 2-methyl Imidazoline, 2-phenylimidazoline, 2,4-diamino-6-vinyl-s-triazine, 2,4-diamino-6-vinyl-s-triazine isocyanuric acid Adduct, 2,4-diamino-6-methacryloyloxyethyl-s-triazine, epoxy imidazole adduct, 2-methylbenzimidazole, 2-octylbenzo Imidazole, 2-pentylbenzimidazole, 2-(1-ethylpentyl)benzimidazole, 2-nonylbenzimidazole, 2-(4-thiazolyl)benzimidazole, benzimidazole, 2- (2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3'-tertiary butyl-5'-methylphenyl)-5-chlorobenzotriazole Azole, 2-(2'-hydroxy-3',5'-bis(tertiary pentyl)phenyl)benzotriazole, 2-(2'-hydroxy-5'-tertiary octylphenyl)benzene Triazole, 2,2'-methylenebis[6-(2H-benzotriazole-2-yl)-4-tertiary octylphenol], 6-(2-benzotriazole) 4 -Tertiary octyl-6'-tertiary butyl-4'-methyl-2,2'-methylene bisphenol, 1,2,3-benzotriazole, 1-[N,N-bis (2-Ethylhexyl)aminomethyl)benzotriazole, carboxybenzotriazole, 1-[N,N-bis(2-ethylhexyl)aminomethyl]methylbenzotriazole, 2,2'-[[(Methyl-1H-benzotriazol-1-yl)methyl]imino]diethanol, 1-(1',2'-dicarboxyethyl)benzotriazole , 1-(2,3-Dicarboxypropyl)benzotriazole, 1-[(2-ethylhexylamino)methyl]benzotriazole, 2,6-bis[(1H-benzotriazole Azol-1-yl)methyl]-4-methylphenol, 5-methylbenzotriazole, 5-phenyltetrazole and the like.

Amine hydrohalides are compounds in which amines react with hydrogen halides. The amines in the amine hydrohalides include ethylamine, ethylenediamine, triethylamine, diphenylguanidine, xylylguanidine, methylimidazole, 2-ethyl-4-methylimidazole, etc., halogenated Examples of hydrogen include hydrides of chlorine, bromine, and iodine.

Examples of organic halogen compounds include: trans-2,3-dibromo-2-butene-1,4-diol, triallyl hexabromoisocyanurate, 1-bromo-2-butane Alcohol, 1-bromo-2-propanol, 3-bromo-1-propanol, 3-bromo-1,2 Propylene glycol, 1.4-dibromo-2-butanol, 1,3-dibromo-2-propanol, 2,3-dibromo-1-propanol, 2,3-dibromo-1,4-butanediol , 2,3-Dibromo-2-butene-1,4-diol, etc.

Examples of the thixotropic agent include wax-based thixotropic agents, amide-based thixotropic agents, and sorbitol-based thixotropic agents.

Examples of the wax-based thixotropic agent include ester compounds, and specific examples include castor oil.

Examples of the amide-based thixotropic agent include monoamide-based thixotropic agent, bis-amide-based thixotropic agent, and polyamide-based thixotropic agent. Specific examples include: laurylamide , Palmitamide, Stearylamine, Behenylamide, Hydroxystearylamide, Saturated Fatty Amide, Oleamide, Glucosamine, Unsaturated Fatty Amide, P-Toluamide, P-Toluamide , Aromatic amides, hexamethylene hydroxystearyl amides, substituted amides, hydroxymethyl stearyl amides, hydroxymethyl amides, fatty acid ester amides and other monoamides; methylene double hard Tallow amide, ethylene dilauram, ethylene dihydroxy fatty acid (the carbon number of the fatty acid is C6 to C24) amide, ethylene dihydroxy stearyl amide, saturated fatty bis amide, methylene bis oleamide, unsaturated Fatty bis-amide, meta-xylene bis-stearyl amide, aromatic bis-amide, etc.; saturated fatty acid polyamide, unsaturated fatty acid polyamide, aromatic polyamide, 1,2,3- Polyamides such as propane tricarboxylic acid tris (2-methylcyclohexyl amide), cyclic amide oligomers, and non-cyclic amide oligomers.

The aforementioned cyclic amide oligomers include: dicarboxylic acid and diamine cyclic polycondensation amide oligomer, tricarboxylic acid and diamine cyclic polycondensation amide oligomer, dicarboxylic acid and Amine oligomers obtained by cyclic condensation polymerization of triamines, amide oligomers obtained by cyclic condensation polymerization of tricarboxylic acids and triamines, amide oligomers obtained by cyclic condensation polymerization of dicarboxylic acids and tricarboxylic acids and diamines , Dicarboxylic acid and tricarboxylic acid and triamine by cyclic polycondensation of amide oligomer, dicarboxylic acid and diamine and triamine by cyclic polycondensation of amide oligomer, tricarboxylic acid and diamine and triamine Amine oligomers obtained by cyclic polycondensation of amines, amide oligomers obtained by cyclic polycondensation of dicarboxylic acids and tricarboxylic acids with diamines and triamines, etc.

In addition, the aforementioned non-cyclic amide oligomers include: the case of non-cyclic polycondensation of monocarboxylic acid and diamine and/or triamine, and dicarboxylic acid and/or tricarboxylic acid The case of non-cyclic polycondensation of amide oligomer with monoamine, etc. In the case of an amide oligomer containing a monocarboxylic acid or a monoamine, the monocarboxylic acid and monoamine function as a terminal molecule and become an acyclic amide oligomer with a lower molecular weight. In addition, when the non-cyclic amide oligomer is a non-cyclic polycondensation of dicarboxylic acid and/or tricarboxylic acid and diamine and/or triamine, it becomes a non-cyclic polymer system. Amide polymer. Furthermore, the non-cyclic amide oligomer also includes the non-cyclic polycondensation of monocarboxylic acid and monoamine.

Examples of sorbitol-based thixotropic viscosity-reducing agents include dibenzylidene-D-sorbitol, bis(4-methylbenzylidene)-D-sorbitol, (D-)sorbitol, and monobenzene Methylene (-D-)sorbitol, mono(4-methylbenzylidene)-(D-)sorbitol, etc.

Examples of the metal deactivator include nitrogen compounds such as hydrazine-based nitrogen compounds, amide-based nitrogen compounds, triazole-based nitrogen compounds, and melamine-based nitrogen compounds; hindered phenol-based compounds.

The term "metal deactivator" here means a compound that has the ability to prevent metal from being degraded due to contact with a certain compound.

Examples of the surfactant include nonionic surfactants and weak cationic surfactants.

Examples of nonionic surfactants include polyoxyalkylene acetylene glycols, polyoxyalkylene glycerol ethers, polyoxyalkylene alkyl ethers, polyoxyalkylene esters, polyoxyalkylene alkylamines, polyoxyalkylene alkylamides, and aliphatic Alcohol polyoxyethylene adduct, aromatic alcohol polyoxyethylene adduct, polyol polyoxyethylene adduct, etc.

Examples of weak cationic surfactants include: terminal diamine polyethylene glycol, terminal diamine polyethylene glycol-polypropylene glycol copolymer, aliphatic amine polyoxyethylene adduct, and aromatic amine polyoxyethylene adduct , Polyamine polyoxyethylene adducts, etc.

Examples of the solvent include water, alcohol-based solvents, glycol ether-based solvents, organic acid ester-based solvents, terpineols, and hydrocarbons.

Examples of alcohol solvents include isopropanol, 1,2-butanediol, isobornylcyclohexanol, 2,4-diethyl-1,5-pentanediol, and 2,2-dimethyl- 1,3-propanediol, 2,5-dimethyl-2,5 hexanediol, 2,5-dimethyl-3-hexyne-2,5-diol, 2,3-dimethyl-2 ,3-Butanediol, 1,1,1-tris(hydroxymethyl)ethane, 2-ethyl-2-hydroxymethyl-1,3-propanediol, 2,2'-oxybis(methylene Base) bis(2-ethyl-1,3-propanediol), 2,2-bis(hydroxymethyl)-1,3-propanediol, 1,2,6-trihydroxyhexane, bis(2,2, 2-Tris(hydroxymethyl)ethyl)ether, 1-ethynyl-1-cyclohexanol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, Erythritol , Threitol, Guaiacol Glycerol Ether, 3,6-dimethyl-4-octyne-3,6-diol, 2,4,7,9-tetramethyl 5-decyne-4,7-diol, 1-hexadecanol, 2-hexyldecanol, isocetyl alcohol, 1-heptadecanol, 1-octadecyl alcohol, isostearyl alcohol, etc.

Examples of glycol ether solvents include: diethylene glycol mono-2-ethylhexyl ether, ethylene glycol monophenyl ether, 2-methylpentane-2,4-diol, and diethylene glycol monohexyl ether , Diethylene glycol dibutyl ether, triethylene glycol monobutyl ether, etc.

Organic acid ester solvents include: dimethyl adipate, diisopropyl adipate, dibutyl maleate, dimethyl sebacate, diisobutyl adipate, sebacate Diethyl sebacate, diisopropyl sebacate, dibutyl sebacate, dioctyl sebacate, etc.

Examples of hydrocarbons include toluene, xylene, and n-hexane.

In the flux used in the solder paste of this embodiment, for example, the content of the resin component relative to the total mass of the flux is preferably 20% by mass to 70% by mass, particularly preferably 35% by mass to 60% by mass. .

For example, the content of the organic acid relative to the total mass of the flux is preferably more than 0% by mass and 15% by mass or less, and more preferably 0.2% by mass or more and 10% by mass or less.

For example, the content of the amine relative to the total mass of the flux is preferably from 0% by mass to 8% by mass, and particularly preferably from 1% by mass to 6% by mass.

For example, the content of the amine hydrohalide relative to the total mass of the flux is preferably from 0% by mass to 8% by mass, and particularly preferably from 0.5% by mass to 5% by mass.

For example, the content of the organic halogen compound relative to the total mass of the flux is preferably from 0% by mass to 8% by mass, and particularly preferably from 0.5% by mass to 6% by mass.

For example, the content of the antioxidant relative to the total mass of the flux is preferably 0% by mass or more and 8% by mass or less, and more preferably 1% by mass or more and 6% by mass or less.

The content of flux:

The content of the flux in the solder paste is preferably 5 to 95% by mass, and more preferably 5 to 15% by mass relative to the total mass of the solder paste.

When the flux content in the solder paste is within this range, the effect of suppressing the increase in viscosity caused by the solder powder can be fully exerted. In addition, it is easy to achieve the effect of the components of the flux. For example, depending on its use conditions or applications, it is easy to achieve the improvement of the wetting speed of the solder, the corrosion suppression of the metal surface of the bonding object (such as copper plate), and the printing Various features such as improved performance and gap suppression.

Manufacturing method of solder paste:

The solder paste of this embodiment can be manufactured by a general method in the industry.

First, the solder powder can be produced by the dropping method of dropping molten solder material to obtain particles, or the spraying method of centrifugal spraying, or the method of crushing the bulk solder material, and other commonly known methods. In the dripping method or spraying method, in order to form particles, the dripping or spraying is preferably performed in an inert gas environment or in a solvent. Then, the above-mentioned components are heated and mixed to prepare a flux, the above-mentioned solder powder is introduced into the flux, and the zirconia powder is introduced as appropriate and stirred and mixed to manufacture.

<Example of the effect of the solder paste of this embodiment>

In the solder paste of this embodiment, a solder powder containing a solder alloy is used, and the solder alloy has an alloy composition with Sn and specific elements (at least one of Bi and Pb and As) in a specific ratio.

In the solder paste that combines the solder powder and flux, it is shown that it is unlikely to cause changes over time such as a rise in viscosity, excellent wettability, and high mechanical properties.

Furthermore, according to this solder paste, by selecting the components blended in the flux, it is possible to further improve the wetting speed of the solder, inhibit the corrosion of the metal surface of the joint object (for example, copper plate), improve the printability, and suppress the voids. And other characteristics.

As mentioned above, the solder paste of this embodiment contains specific solder powder and flux.

The specific solder powder may include solder powder containing any one of the following solder alloys (S1) to solder alloys (S5) as a preferred embodiment.

Solder alloy (S1):

The system has: As: 10 mass ppm or more and less than 40 mass ppm, and at least one of Bi: 0 to 25,000 mass ppm and Pb: 0 to 8,000 mass ppm, and the remainder is an alloy composed of Sn, And satisfy the following (1) formula and (2) type solder alloy.

300≦3As+Bi+Pb (1)

0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2)

In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition.

Solder alloy (S2):

The system has: As: 10 mass ppm or more and less than 40 mass ppm, Bi: more than 0 mass ppm and less than 25,000 mass ppm, and Pb: more than 0 mass ppm and at least one of 8000 mass ppm or less, and The remaining part is the alloy composition composed of Sn, and the solder alloy that satisfies the following formulas (1) and (2).

300≦3As+Bi+Pb (1)

0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2)

In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition.

Solder alloy (S3):

The system has: from As: 10 mass ppm or more and less than 40 mass ppm, and Bi: 50 to 25,000 mass ppm, and Pb: more than 0 mass ppm and at least one of 8000 mass ppm, and the remainder is Sn The alloy composition of the composition, and the solder alloy that satisfies the following formula (1) and (2).

300≦3As+Bi+Pb (1)

0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2)

In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition.

Solder alloy (S4):

The system has: As: 10 mass ppm or more and less than 40 mass ppm, and Bi: more than 0 mass ppm and less than 25,000 mass ppm, and Pb: at least one of 50 to 8,000 mass ppm, and the remainder is Sn The alloy composition of the composition, and the solder alloy that satisfies the following formula (1) and (2).

300≦3As+Bi+Pb (1)

0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2)

In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition.

Solder alloy (S5):

The system has: As: 10 mass ppm or more and less than 40 mass ppm, and at least one of Bi: 50 to 25,000 mass ppm and Pb: 50 to 8,000 mass ppm, and the remainder is an alloy composed of Sn, And satisfy the following (1) formula and (2) type solder alloy.

300≦3As+Bi+Pb (1)

0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2)

In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition.

The flux in the solder paste of this embodiment is not particularly limited. For example, one containing a resin component, an active component, and a solvent can be used.

The flux can include the following flux (F1) to flux (F12) as a preferred embodiment.

Flux (F1):

The flux (F1) is a composition containing acid-modified rosin, and examples include acid-modified rosin, a thixotropic viscosity reducer, and a solvent.

Acid-modified rosin has heat resistance in the temperature range assumed during welding, and functions as an active agent during welding.

The acid-modified rosin contained in the flux (F1) is preferably selected from the group consisting of acrylic-modified rosin, acrylic-modified hydrogenated rosin, maleic acid-modified rosin, and maleic acid-modified hydrogenated rosin At least one of the group.

The content of acid-modified rosin relative to the total flux (F1) is preferably 3.0% by mass or more and 60.0% by mass or less, more preferably 5.0% by mass or more and 50.0% by mass or less, and more preferably 10.0% by mass or more and 50.0% by mass %the following.

The thixotropic agent used in the flux (F1) includes, for example, an amide-based thixotropic agent, a sorbitol-based thixotropic agent, and a wax-based thixotropic agent (ester compound).

The content of the thixotropic viscosity reducing agent relative to the total mass of the flux (F1) is preferably 0.1 to 15.0 mass%, and more preferably 0.2 mass% or more and 10.0 mass% or less.

Examples of the solvent used for the flux (F1) include water, alcohol-based solvents, glycol ether-based solvents, and terpineols.

The flux (F1) may contain rosin (other rosin) other than acid-modified rosin. Examples of other rosins include raw rosins such as gum rosin, wood rosin, and tall oil rosin, and derivatives derived from the raw rosin. Examples of the derivatives include: refined rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, phenol-modified rosin, and refined products, hydrogenated products, and disproportionated products of the polymerized rosin. One or two of these can be used. the above.

The flux (F1) preferably contains more than 0% by mass and 60.0% by mass or less of other rosin, and more preferably contains more than 0% by mass and 45% by mass or less.

The flux (F1) preferably contains acid-modified rosin and other rosins in a total of 20% by mass to 70% by mass, and more preferably 35% by mass to 60% by mass in total.

The flux (F1) may contain organic acids, amines, halogen-based activators, and antioxidants. The flux (F1) may further contain a surfactant.

By combining the above-mentioned flux (F1) and solder powder containing any one of solder alloys (S1) to solder alloys (S5), it is possible to provide a viscosity increase that does not easily cause changes over time, such as an increase in viscosity, and has excellent wettability. A solder paste that has high mechanical properties and has improved the wetting speed of the solder.

In addition, according to the flux (F1), it is possible to provide a flux for solder paste that can obtain a good wetting speed even under conditions of large heat load.

Flux (F2):

The flux (F2) is a composition containing an acrylic resin, and examples thereof include those containing an acrylic resin, an organic acid, and a solvent.

Acrylic resin has heat resistance in the temperature range assumed in soldering, and the flux residue becomes soft residue by remaining in the flux residue that hardens after heating. Thereby, even if the temperature changes, the cracking of the flux residue can be suppressed, and the reliability of the temperature cycle can be improved.

The acrylic resin contained in the flux (F2) uses acrylic acid, the acrylate of the reaction product of acrylic acid and alcohol, and the methacrylate of the reaction product of methacrylic acid and methacrylic acid and alcohol as monomers. Examples include: Acrylic acid polymer, acrylic acid ester polymer, acrylic acid and acrylic acid ester polymer, etc.

In addition, a polymer of methacrylic acid, a polymer of methacrylate, a polymer of methacrylic acid and methacrylate, and the like can be cited.

Furthermore, examples include: polymers of acrylic acid and methacrylic acid, polymers of acrylic acid and methacrylate, polymers of methacrylic acid and acrylate, polymers of acrylate and methacrylate, acrylic acid and methacrylate Acrylic acid and acrylic acid ester polymer, acrylic acid and methacrylic acid and methacrylic acid ester polymer, acrylic acid and methacrylic acid and acrylic acid ester and methacrylic acid ester polymer, acrylic acid With acrylate and methacrylate polymers, methacrylic acid, acrylate and methacrylate polymers, etc.

Examples of acrylic esters include butyl acrylate, and acrylic resins that use butyl acrylate as a monomer include butyl acrylate polymers, acrylates other than butyl acrylate and butyl acrylate polymers, acrylic acid and acrylic acid. Polymers of butyl ester, polymers of acrylic acid and butyl acrylate other than acrylic acid and butyl acrylate, etc.

In addition, examples of methacrylates include butyl methacrylate, and examples of acrylic resins using butyl methacrylate as a monomer include polymers of butyl methacrylate and methyl methacrylate other than butyl methacrylate. A polymer of methacrylic acid ester and butyl methacrylate, a polymer of methacrylic acid and butyl methacrylate, a polymer of methacrylic acid and butyl methacrylate other than methacrylic acid and butyl methacrylate Wait.

In addition, the polymer of acrylic acid and butyl methacrylate, the polymer of methacrylate and butyl methacrylate other than acrylic acid and butyl methacrylate, the polymerization of methacrylic acid and butyl acrylate Polymers, polymers of acrylate and butyl acrylate other than methacrylic acid and butyl acrylate, polymers of butyl acrylate and butyl methacrylate, polymers of acrylate and butyl methacrylate other than butyl acrylate , Butyl acrylate and methacrylate polymers other than butyl methacrylate, etc.

The polymerization reaction may be random copolymerization or block copolymerization.

In addition, the above-mentioned alcohol-based alcohols have a linear carbon chain with 1 to 24 carbons or a branched carbon chain with 3 to 24 carbons. Examples of the above-mentioned alcohols include: methanol with carbon number 1, carbon number 2 ethanol, carbon number 3 1-propanol, carbon number 3 2-propanol, carbon number 3 ethylene glycol monomethyl ether, carbon number 4 1-butanol, carbon number 4 2-butanol , Isobutanol with 4 carbons, 1-hexanol with 6 carbons, diethylene glycol monoethyl ether with 6 carbons, 7 carbons Benzyl alcohol, 1-octanol with 8 carbons, 2-ethylhexanol with 8 carbons, phenyl glycol with 8 carbons, 1-decanol with 9 carbons, and laurel with 12 carbons Alcohol, cetyl alcohol with 16 carbons, stearyl alcohol with 18 carbons, oleyl alcohol with 18 carbons, and behenyl alcohol with 22 carbons.

Regarding the molecular weight of the acrylic resin, the weight average molecular weight (Mw) measured by gel permeation chromatography (GPC: Gel Permeation Chromatography) in terms of polystyrene is preferably 5000 to 30,000, and the weight average molecular weight (Mw ) Is particularly preferably 6000 to 15000.

The acrylic resin may include: poly-2-ethylhexyl acrylate (Mw=8300), poly-2-ethylhexyl acrylate (Mw=11700) with different molecular weights, polylauryl methacrylate (Mw=10080) )Wait.

In addition, the acrylic resin may be a polymer of the aforementioned acrylic resin and other resins, for example, a copolymer of the aforementioned acrylic resins and polyethylene. Examples of the acrylic-polyethylene copolymer resin include polyacrylic acid 2-ethylhexyl-polyethylene (Mw=12300) and the like.

The content of acrylic resin relative to the total mass of the flux (F2) is preferably 5 mass% or more and 50 mass% or less, particularly preferably 5 mass% or more and 45% by mass or less, and more preferably 10 mass% or more and 30 mass% or less .

The content of the organic acid used in the flux (F2) relative to the total mass of the flux (F2) is preferably more than 0% by mass and 15% by mass or less, and more preferably 0.2% by mass or more and 13% by mass or less.

Examples of the solvent used for the flux (F2) include water, alcohol-based solvents, glycol ether-based solvents, and terpineols.

The flux (F2) may contain more than 0% by mass and 45.0% by mass or less of rosin. When rosin is contained, the total content of one type of rosin or two or more types of rosin and one type of acrylic resin or two or more types of acrylic resins is preferably 35.0% by mass or more and 60.0% by mass or less.

In addition, when rosin is contained, the ratio of the total content of one type of rosin or two or more types of rosin to the total content of one type of acrylic resin or two or more types of acrylic resin (total amount of rosin/total amount of acrylic resin) , Preferably 0.1 or more and 9..0 or less.

The flux (F2) may contain resins other than acrylic resins and rosin-based resins, and may contain other resins in an amount of 0% by mass or more and 10.0% by mass or less.

The flux (F2) may further contain amines and halogens.

Relative to the total mass of the flux (F2), it is preferable to contain 0% by mass or more and 20.0% by mass or less of amine, more preferably 0% by mass to 5.0% by mass, and in addition, relative to the total mass of flux (F2) In terms of halogen, it is preferable to contain 0% by mass or more and 2.0% by mass or less of amine hydrohalide, and it is particularly preferable to contain 0% by mass or more and 5.0% by mass or less.

The flux (F2) may contain a thixotropic viscosity reducing agent, and it is preferable to contain 0 mass% or more and 10.0 mass% or less of the thixotropic viscosity reducing agent relative to the total mass of the flux (F2).

An amide-based thixotropic agent can be contained as a thixotropic agent. Relative to the total mass of the flux (F2), it is preferable to contain 0% by mass to 10.0% by mass of the amide-based thixotropic agent, especially It preferably contains 0% by mass or more and 6.0% by mass or less.

In addition, the flux (F2) may contain an ester compound as a thixotropic reducer. It is preferable to contain 0% by mass or more and 8.0% by mass or less of the ester compound relative to the total mass of the flux (F2), and more preferably 0% by mass. Above 4.0% by mass or less.

Furthermore, the flux (F2) may contain a sorbitol-based thixotropic reducer as a thixotropic reducer, and preferably contains 0% by mass to 10.0% by mass of sorbitol relative to the total mass of the flux (F2) It is a thixotropic viscosity reducer, and preferably contains 0 mass% or more and 6.0 mass% or less.

The total content of the plurality of thixotropic viscosity reducers is preferably 10.0% by mass or less with respect to the total mass of the flux (F2).

The flux (F2) may further contain an antioxidant, and it is preferable to contain 0% by mass or more and 5.0% by mass or less of the antioxidant relative to the total mass of the flux (F2).

By combining the above-mentioned flux (F2) and solder powder containing any one of solder alloy (S1) to solder alloy (S5), it is possible to provide a viscosity increase and other changes over time such as excellent wettability. A solder paste with high mechanical properties and excellent temperature cycle reliability of flux residues.

In addition, according to the flux (F2), it is possible to provide a flux for solder paste that makes the residue flexible and can suppress the cracking of the residue, thereby obtaining the effect of excellent temperature cycle reliability.

Flux (F3):

Flux (F3) is a reaction of dimer acid containing dimers selected from reactants belonging to monocarboxylic acids, hydrogenated dimer acid obtained by adding hydrogen to the dimer acid, and belonging to monocarboxylic acids It is a composition of at least one organic acid in the group consisting of a trimer acid of a trimer and a hydrogenated trimer acid obtained by adding hydrogen to the trimer acid.

The flux (F3) includes, for example, containing at least one organic acid selected from the group consisting of the dimer acid, the hydrogenated dimer acid, the trimer acid, and the hydrogenated trimer acid , And rosin, and thixotropic viscosity reducer, and solvent.

Dimer acid and trimer acid have heat resistance in the temperature range assumed in welding, and function as an active agent during welding.

The dimer acid and trimer acid contained in the flux (F3) include: dimer acid, which is a reactant of oleic acid and linoleic acid, and trimer acid, which is a reactant of oleic acid and linoleic acid. , Dimer acid of the reactant of acrylic acid, trimer acid of the reactant of acrylic acid, dimer acid of the reactant of methacrylic acid, Trimer acid of the reactant of methacrylic acid, dimer acid of the reactant of acrylic acid and methacrylic acid, trimer acid of the reactant of acrylic acid and methacrylic acid, dimer acid of the reactant of oleic acid , Trimer acid of the reactant of oleic acid, dimer acid of the reactant of linoleic acid, trimer acid of the reactant of linoleic acid, dimer acid of the reactant of hypolinoleic acid, secondary Trimer acid of the reactant of linoleic acid, dimer acid of the reactant of acrylic acid and oleic acid, trimer acid of the reactant of acrylic acid and oleic acid, dimer of the reactant of acrylic acid and linoleic acid Acid, the terpolymer of the reactant of acrylic acid and linoleic acid, the dimer acid of the reactant of acrylic acid and linolenic acid, the terpolymer of the reactant of acrylic acid and linolenic acid, methacrylic acid and The dimer acid of the reactant of oleic acid, the trimer acid of the reactant of methacrylic acid and oleic acid, the dimer acid of the reactant of methacrylic acid and linoleic acid, the dimer acid of the reactant of methacrylic acid and linoleic acid Trimer acid of the reactant, dimer acid of the reactant of methacrylic acid and linolenic acid, trimer acid of the reactant of methacrylic acid and linolenic acid, oleic acid and linolenic acid The dimer acid of the reactant, the trimer acid of the reactant of oleic acid and hypolinolenic acid, the dimer acid of the reactant of linoleic acid and hypolinolenic acid, the dimer acid of the reactant of linoleic acid and hypolinolenic acid The trimer acid of the reactant, the dimer acid of the hydride of each of the above dimer acids, the trimer acid of the hydride of each of the above-mentioned trimer acids, etc.

For example, the dimer acid of the reactant of oleic acid and linoleic acid is a dimer with 36 carbon atoms. In addition, the terpolymer acid of the reactant of oleic acid and linoleic acid is a trimer with 54 carbon atoms.

The flux (F3) preferably contains 0.5% by mass to 20% by mass relative to the total mass of the flux, selected from dimer acids, hydrogenated dimer acids, trimer acids, and hydrogenated trimer acids. At least one of the constituent groups preferably contains 2% by mass or more and 10% by mass or less.

When the content of at least one selected from the group consisting of dimer acid, hydrogenated dimer acid, trimer acid, and hydrogenated trimer acid is 0.5% by mass or more, it is easier to obtain the wetting spread of the solder Inhibition of poor solder wettability (dehumidification).

In addition to at least one selected from the group consisting of dimer acids, hydrogenated dimer acids, trimer acids, and hydrogenated trimer acids, the flux (F3) can also use organic acids other than these .

The organic acid other than these is preferably at least one selected from the group consisting of succinic acid, glutaric acid and adipic acid. The content of at least one selected from the group consisting of succinic acid, glutaric acid, and adipic acid is preferably 0.1% by mass to 5% by mass relative to the total mass of the flux.

The total content of at least one selected from the group consisting of dimer acids, hydrogenated dimer acids, trimer acids, and hydrogenated trimer acids and other organic acids, relative to the total mass of the flux It is preferably 0.5% by mass or more and 20% by mass or less, more preferably 3% by mass or more and 15% by mass or less, and more preferably 5% by mass or more and 10% by mass or less.

The rosin used in the flux (F3) includes, for example, natural rosin and derivatives derived from the natural rosin. Examples of natural rosin include gum rosin, wood rosin, tall oil rosin, and the like. Examples of such derivatives include refined rosin and modified rosin. The modified rosin includes hydrogenated rosin, polymerized rosin, disproportionated rosin, acid-modified rosin, rosin ester, phenol-modified rosin, and α,β-unsaturated carboxylic acid-modified products (acrylated rosin, maleated rosin, Fumarated rosin, acrylic modified hydrogenated rosin, etc.), as well as refined products, hydrides and disproportions of the polymerized rosin, and refined products, hydrides and disproportions of the modified α,β unsaturated carboxylic acids, etc., One or two or more of these can be used.

The flux (F3) preferably contains 15% by mass or more and 70% by mass or less of rosin, and more preferably contains 35% by mass or more and 60% by mass or less of rosin.

The thixotropic agent used in the flux (F3) includes, for example, an amide-based thixotropic agent, a sorbitol-based thixotropic agent, and a wax-based thixotropic agent (ester compound). The content of the thixotropic viscosity-reducing agent is preferably 0.1 to 15.0% by mass relative to the total mass of the flux (F3), and more preferably 0.2% by mass or more and 10.0% by mass or less.

Examples of the solvent used for the flux (F3) include water, alcohol-based solvents, glycol ether-based solvents, and terpineols.

The flux (F3) may contain components other than organic acids, rosin, thixotropic viscosity reducers, and solvents, and examples thereof include amines, halogen-based activators, antioxidants, resin components other than rosin, surfactants, and the like.

By combining the above-mentioned flux (F3) and solder powder containing any one of solder alloy (S1) to solder alloy (S5), it is possible to provide a viscosity increase and other changes over time such as excellent wettability. A solder paste with high mechanical properties, good solder wetting and spreading, and suppression of dewetting.

In addition, according to the flux (F3), it is possible to provide a flux for solder paste that exhibits good wettability and spreadability even under conditions of large heat load, and can suppress the generation of dehumidification.

Flux (F4):

The flux (F4) is a composition containing a compound represented by the following general formula (1).

Examples of the flux (F4) include those containing a compound represented by the following general formula (1), rosin, and a solvent.

In the formula (1), R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

In the aforementioned general formula (1), R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The alkyl group having 1 to 4 carbon atoms includes methyl, ethyl, propyl, cyclopropyl, butyl, and cyclobutyl. Among them, R ¹ , R ² , R ³ and R ^{4 are} preferably a hydrogen atom, a methyl group, an ethyl group, or a cyclopropyl group, particularly preferably a hydrogen atom and a methyl group, and particularly preferably a hydrogen atom. R ¹ , R ² , R ³ and R ⁴ may be the same or different.

The compounds represented by the aforementioned general formula (1) include: pyridine-2-carboxylic acid, 6-methylpyridine-2-carboxylic acid, 6-ethylpyridine-2-carboxylic acid, 3-cyclopropylpyridine-2- Formic acid, 4-cyclopropylpyridine-2-carboxylic acid, 6-cyclopropylpyridine-2-carboxylic acid, 5-butylpyridine-2-carboxylic acid, 6-cyclobutylpyridine-2-carboxylic acid, etc. Among these, pyridine-2-carboxylic acid is particularly preferred.

The compound represented by general formula (1) can be used individually by 1 type or in mixture of 2 or more types.

The flux (F4) preferably contains the compound represented by the general formula (1) of 0.5% by mass to 7% by mass relative to the total mass of the flux (F4), and more preferably 1.0% by mass or more and 7.0% by mass The compound represented by the general formula (1) below more preferably contains 3.0% by mass or more and 7.0% by mass or less, and particularly preferably contains 3.0% by mass or more and 5.0% by mass or less.

The rosin used in the flux (F4) includes, for example, raw rosin such as gum rosin, wood rosin, and tall oil rosin, and derivatives derived from the raw rosin. Examples of the derivatives include: refined rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, acid-modified rosin, phenol-modified rosin, and α,β-unsaturated carboxylic acid-modified products (acrylated rosin, maleated rosin) , Fumarated rosin, etc.), as well as refined products, hydrides and disproportions of the polymerized rosin, and refined products, hydrides and disproportions of the α,β unsaturated carboxylic acid modification products, etc., which can be used One kind or two or more kinds.

The flux (F4) preferably contains 30% by mass or more and 60% by mass or less of rosin relative to the total mass of the flux (F4), and more preferably contains 35% by mass or more and 60% relative to the total mass of the flux (F4). Less than mass%.

Examples of the solvent used in the flux (F4) include water, alcohol-based solvents, glycol ether-based solvents, and terpineols.

The flux (F4) can also be used in combination with an organic acid (excluding the compound represented by the general formula (1)). The organic acid can be used without any particular limitation. Preferably, for example, at least one selected from the group consisting of succinic acid, glutaric acid, adipic acid, and hydrogenated dimer acid can be used.

In the flux (F4), in the case where the compound represented by the general formula (1) and the organic acid are not used together (excluding the compound represented by the general formula (1)), it is preferable to contain relative to the flux ( F4) The compound represented by the general formula (1) whose total mass is 1% by mass or more and 7 mass% or less, more preferably the compound represented by the general formula (1) containing 2% by mass or more and 7% by mass or less, and more Preferably, the compound represented by the general formula (1) is contained at 3% by mass or more and 7% by mass or less, and particularly preferably, the compound represented by the general formula (1) is contained at 3% by mass or more and 5% by mass or less.

In the flux (F4), when the compound represented by the general formula (1) is used in combination with an organic acid (excluding the compound represented by the general formula (1)), it is preferable to contain a relative to the flux (F4) The total mass of) is 0.5% by mass or more and 7% by mass or less of the compound represented by general formula (1), particularly preferably containing 0.5% by mass or more and 5 mass% or less of the compound represented by general formula (1), more preferably Contains 1% by mass to 5% by mass of the compound represented by the general formula (1).

The flux (F4) preferably contains 0 mass% or more and 10 mass% or less of organic acid relative to the total mass of the flux (F4), more preferably contains 0.2 mass% or more and 10 mass% or less, and more preferably contains 0.5 mass% Above 8% by mass, particularly preferably 1% by mass to 6% by mass.

In addition, relative to the total mass of the flux (F4), it is preferable to contain the compound represented by the general formula (1) and the aforementioned organic acid (excluding the compound represented by the general formula (1) in a total amount of 3% by mass or more). The total content is more preferably 5% by mass or more, more preferably 6% by mass or more in total, and particularly preferably 6.5% by mass or more and 15% by mass or less in total.

The flux (F4) may further contain amines, organic halogen compounds, and amine hydrohalides.

In addition, the flux (F4) can contain a thixotropic reducer. The thixotropic agent used for the flux (F4) includes, for example, an amide-based thixotropic agent, a sorbitol-based thixotropic agent, and a wax-based thixotropic agent (ester compound).

The content of the thixotropic viscosity reducing agent is preferably 0.1 to 15.0% by mass relative to the total mass of the flux (F4), and more preferably 0.2% by mass or more and 10.0% by mass or less.

In addition, the flux (F4) may further contain, for example, resin components other than rosin, surfactants, antioxidants, and the like.

By combining the above-mentioned flux (F4) and solder powder containing any one of solder alloy (S1) to solder alloy (S5), it is possible to provide a viscosity increase that does not easily cause changes over time, such as an increase in viscosity, and has excellent wettability. A solder paste with high mechanical properties and improved solder wettability.

In addition, according to the flux (F4), it is possible to provide a flux for solder paste that can increase the effect of suppressing the increase in viscosity and improve the solder wettability of the metal surface of the object to be joined.

Flux (F5):

The flux (F5) is a composition containing azoles.

Examples of the flux (F5) include those containing azoles, organic acids, rosin, and solvents. According to this type, the corrosion inhibitory properties of the metal surface (for example, copper plate) of the joining object can be improved.

The term "azoles" here means a compound having a five-membered heterocyclic structure containing one or more nitrogen atoms, and also includes a condensed ring of the five-membered heterocyclic structure and other ring structures.

Examples of the azoles include: 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-benzene 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole , 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 2-phenyl Imidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H -Pyrrole [1,2-a]benzimidazole, epoxy imidazole adduct, 2-methylbenzimidazole, 2-octylbenzimidazole, 2-pentylbenzimidazole, 2-(1- Ethylpentyl)benzimidazole, 2-nonylbenzimidazole, 2-(4-thiazolyl)benzimidazole, benzimidazole, 2-(2'-hydroxy-5'-methylphenyl)benzene Triazole, 2-(2'-hydroxy-3'-tertiary butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5' -Di(tertiary pentyl)phenyl)benzotriazole, 2-(2'-hydroxy-5'-tertiary octylphenyl)benzotriazole, 2,2'-methylenebis[6 -(2H-benzotriazol-2-yl)-4-tertiary octylphenol], 1,2,3-benzotriazole, 1-[N,N-bis(2-ethylhexyl)amine Methyl]benzotriazole, carboxybenzotriazole, 1-[N,N-bis(2-ethylhexyl)aminomethyl]methylbenzotriazole, 2,2'-[[( Methyl-1H-benzotriazol-1-yl)methyl)imino)diethanol, 1-(1',2'-dicarboxyethyl)benzotriazole, 1-(2,3- Dicarboxypropyl)benzotriazole, 1-[(2-ethylhexylamino)methyl]benzotriazole, 2,6-bis[(1H-benzotriazol-1-yl)methyl ]-4-methylphenol, 5-methylbenzotriazole, 5-phenyltetrazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl -2-phenylimidazole salt trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4- Diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'- Methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine Pyrazine isocyanuric acid adduct, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2-phenylimidazoline, 6-(2- Benzotriazolyl) 4-tertiary octyl-6'-tertiary butyl-4'-methyl-2,2'-methylene bisphenol and the like.

The azoles can be used individually by 1 type or in mixture of 2 or more types.

The azoles are preferably at least selected from the group consisting of 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecylimidazole, benzimidazole and 2-octylbenzimidazole One, particularly preferably contains 2-phenylimidazole.

The flux (F5) preferably contains 0.1% by mass or more and 10% by mass or less of azoles relative to the total mass of the flux (F5), and more preferably contains 0.5% by mass or more relative to the total mass of the flux (F5) 5.0% by mass or less.

The content of the organic acid used in the flux (F5) relative to the total mass of the flux (F5) is preferably 0.5% by mass to 20% by mass, particularly preferably 3% by mass to 18% by mass.

In the flux (F5), the ratio of the content of the organic acid to the content of the azole is calculated as the mass ratio expressed by the content of organic acid/the content of azole, preferably 0.5 or more and 10 or less, particularly preferably 1 or more and 9 the following. If this mass ratio is within the aforementioned preferable range, it is easier to improve the corrosion inhibitory properties of the metal surface (for example, copper plate) of the joining object.

In the flux (F5), the total amount of the content of the organic acid and the content of the azole relative to the total mass of the flux (F5) is preferably 3% by mass or more and 25% by mass or less, particularly preferably 5% by mass or more. 20 Mass% or less, more preferably 5 mass% or more and 18 mass% or less, particularly preferably 5 mass% or more and 15 mass% or less.

The rosin used in the flux (F5) includes, for example, raw rosin such as gum rosin, wood rosin, and tall oil rosin, and derivatives derived from the raw rosin. Examples of the derivatives include: refined rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, acid-modified rosin, phenol-modified rosin, and α,β-unsaturated carboxylic acid-modified products (acrylated rosin, maleated rosin) , Fumarated rosin, etc.), as well as refined products, hydrides and disproportions of the polymerized rosin, and refined products, hydrides and disproportions of the α,β unsaturated carboxylic acid modification products, etc., which can be used One kind or two or more kinds.

The flux (F5) preferably contains 30% by mass or more and 60% by mass or less of rosin relative to the total mass of the flux (F5), and more preferably contains 35% by mass or more and 60% relative to the total mass of the flux (F5). Less than mass%.

Examples of the solvent used in the flux (F5) include water, alcohol-based solvents, glycol ether-based solvents, and terpineols.

The flux (F5) may further contain amines, organic halogen compounds, and amine hydrohalides.

In addition, the flux (F5) can contain a thixotropic reducer. Examples of the thixotropic agent used in the flux (F5) include amide-based thixotropic agents, sorbitol-based thixotropic agents, wax-based thixotropic agents (ester compounds), and the like.

The content of the thixotropic viscosity reducing agent relative to the total mass of the flux (F5) is preferably 0.1 to 15.0 mass%, more preferably 0.2 mass% or more and 10.0 mass% or less, more preferably 1.0 mass% or more and 10.0 mass% or less , Particularly preferably 2.0% by mass or more and 8.3% by mass or less.

In addition, the flux (F5) may further contain, for example, resin components other than rosin, surfactants, antioxidants, and the like.

By combining the above-mentioned flux (F5) and solder powder containing any one of solder alloy (S1) to solder alloy (S5), it is possible to provide a viscosity increase and other changes over time such as excellent wettability. A solder paste that has high mechanical properties and can improve the corrosion inhibiting ability of the metal surface of the object to be joined (for example, a copper plate).

In addition, according to the flux (F5), it is possible to provide a flux for solder paste that can improve the corrosion inhibitory properties of the metal surface (for example, copper plate) of the object to be joined.

Flux (F6):

The flux (F6) is a composition containing an aromatic guanidine compound.

The flux (F6) includes, for example, those containing an aromatic guanidine compound, rosin, an organic acid, and a solvent.

Examples of the aromatic guanidine compound include diphenyl guanidine (Diphenyl Guanidine) and xylyl guanidine (Ditolyl Guanidine).

An aromatic guanidine compound can be used individually by 1 type or in mixture of 2 or more types.

The aforementioned aromatic guanidine compound is preferably at least one selected from the group consisting of diphenylguanidine and xylylguanidine, and particularly preferably contains diphenylguanidine.

The flux (F6) preferably contains 0.2% by mass or more and 15% by mass or less of aromatic guanidine compounds relative to the total mass of the flux (F6), and more preferably contains 0.5% by mass or more and 7.0% by mass or less of aromatic guanidine compounds. .

The rosin used in the flux (F6) includes, for example, natural rosin and derivatives derived from the natural rosin. Examples of natural rosin include gum rosin, wood rosin, tall oil rosin, and the like. Examples of such derivatives include refined rosin and modified rosin. The modified rosin includes hydrogenated rosin, polymerized rosin, disproportionated rosin, acid-modified rosin, rosin ester, phenol-modified rosin, and α,β-unsaturated carboxylic acid-modified products (acrylated rosin, maleated rosin, Fumarated rosin, acrylic modified hydrogenated rosin, etc.), as well as refined products, hydrides and disproportions of the polymerized rosin, and refined products, hydrides and disproportions of the modified α,β unsaturated carboxylic acids, etc., One or two or more of these can be used.

The flux (F6) preferably contains 15% by mass or more and 70% by mass or less of rosin relative to the total mass of the flux (F6), and more preferably contains 35% by mass or more and 60% relative to the total mass of the flux (F6). Less than mass%.

The content of the organic acid used in the flux (F6) relative to the total mass of the flux (F6) is preferably 0.1% by mass to 15% by mass, and more preferably 0.2% by mass to 10% by mass.

In the flux (F6), relative to the total mass of the flux (F6), it is preferable to contain a total of 2% by mass to 18% by mass of organic acid and aromatic guanidine compound, and more preferably a total of 3% by mass Above 18% by mass.

Examples of the solvent used in the flux (F6) include water, alcohol-based solvents, glycol ether-based solvents, and terpineols.

Flux (F6) can further contain thixotropic viscosity reducer.

The thixotropic agent used in the flux (F6) includes, for example, an amide-based thixotropic agent, a sorbitol-based thixotropic agent, and a wax-based thixotropic agent (ester compound).

The content of the thixotropic viscosity reducing agent is preferably 0.1 to 15.0% by mass relative to the total mass of the flux (F6), and more preferably 0.2% by mass or more and 10.0% by mass or less.

The flux (F6) may further contain amines, organic halogen compounds, and amine hydrohalides.

In addition, the flux (F6) may further contain, for example, resin components other than rosin, surfactants, antioxidants, and the like.

By combining the above-mentioned flux (F6) with solder powder containing any one of solder alloys (S1) to solder alloys (S5), it is possible to provide a viscosity increase and other changes over time such as excellent wettability. A solder paste that has high mechanical properties and has improved the wetting speed of the solder with respect to the metal surface of the object to be joined.

In addition, according to the flux (F6), it is possible to provide a flux for solder paste that has a high wetting rate of the solder with respect to the metal surface of the object to be joined and good solder wettability.

Flux (F7):

The flux (F7) is a composition containing an amide-based thixotropic agent, which is a amide compound.

The flux (F7) includes, for example, a thixotropic agent containing the aforementioned amide compound, an organic acid, and at least one selected from the group consisting of rosin-based resins and acrylic resins. Resin components and solvents.

Examples of the amide-based thixotropic viscosity-reducing agent (amide compound) include polyamide, bisamide, and monoamide.

The amide-based thixotropic viscosity reducing agent (amide compound) includes, for example, lauryl amide, palm amide, stearyl amide, behenyl amide, hydroxystearyl amide, saturated fatty amide, and oleamide. Amine, mustard amide, unsaturated fatty amide, p-toluamide, p-toluene methane amide, aromatic amide, hexamethylene hydroxystearyl amide, substituted amide, methylol stearyl amide, Monoamides such as hydroxymethyl amide, fatty acid ester amide, etc.; methylene bisstearyl amide, ethylene bislauric amide, ethylene dihydroxy fatty acid (fatty acid carbon number C6 to C24) amide, ethylene bis Diamides such as hydroxystearyl amide, saturated fatty diamide, methylene dioleyl amide, unsaturated aliphatic diamide, meta-xylene distearic amide, aromatic diamide, etc.; saturated fatty acid polyamide Amide, unsaturated fatty acid polyamide, aromatic polyamide, 1,2,3-propane tricarboxylic acid tris (2-methylcyclohexyl amide), cyclic amide oligomer, non-cyclic amide Polyamides such as amine oligomers.

The aforementioned cyclic amide oligomers include: dicarboxylic acid and diamine cyclic polycondensation amide oligomer, tricarboxylic acid and diamine cyclic polycondensation amide oligomer, dicarboxylic acid and Amine oligomers obtained by cyclic condensation polymerization of triamines, amide oligomers obtained by cyclic condensation polymerization of tricarboxylic acids and triamines, amide oligomers obtained by cyclic condensation polymerization of dicarboxylic acids and tricarboxylic acids and diamines , Dicarboxylic acid and tricarboxylic acid and triamine by cyclic polycondensation of amide oligomer, dicarboxylic acid and diamine and triamine by cyclic polycondensation of amide oligomer, tricarboxylic acid and diamine and triamine Amine oligomers obtained by cyclic polycondensation of amines, amide oligomers obtained by cyclic polycondensation of dicarboxylic acids and tricarboxylic acids with diamines and triamines, etc.

In addition, the aforementioned non-cyclic amide oligomers include: the case of non-cyclic polycondensation of monocarboxylic acid and diamine and/or triamine, and dicarboxylic acid and/or tricarboxylic acid The case of non-cyclic polycondensation of amide oligomer with monoamine, etc. When it is an amide oligomer containing monocarboxylic acid or monoamine, monocarboxylic acid, monoamine It functions as terminal molecules and becomes a non-cyclic amide oligomer with reduced molecular weight. In addition, when the non-cyclic amide oligomer is a non-cyclic polycondensation of dicarboxylic acid and/or tricarboxylic acid and diamine and/or triamine, it becomes a non-cyclic polymer system. Amide polymer. Furthermore, the non-cyclic amide oligomer also includes the non-cyclic polycondensation of monocarboxylic acid and monoamine.

The amide-based thixotropic agent (amide compound) contained in the flux (F7) of this embodiment is preferably selected from the group consisting of polyamide, bisamide and monoamide At least one of them. Among them, it is particularly preferable to use the group selected from the group consisting of p-toluamide, ethylene dihydroxy fatty acid (C6 to C24) amide, hexamethylene hydroxystearyl amide, polyamide and cyclic amide oligomer At least one of them.

The content of the amide-based thixotropic viscosity-reducing agent of the flux (F7) of this embodiment is preferably more than 0% by mass and 15% by mass or less relative to the total mass of the aforementioned flux (F7), especially 1.5% by mass or more and 10.0% by mass or less.

Examples of thixotropic agents other than amide compounds include wax-based thixotropic agents. Examples of the wax-based thixotropic agent include ester compounds, and specific examples include castor oil. The flux of this embodiment preferably contains an ester compound of 0% by mass to 15% by mass relative to the total mass of the aforementioned flux (F7), and more preferably contains more than 0% by mass and 12.0% by mass.

The flux of this embodiment preferably contains 3.0% by mass to 15.0% by mass in total with respect to the total mass of the aforementioned flux (F7), which are thixotropic viscosity-reducing agents, especially amide compounds and ester compounds. Contains 5.0% by mass or more and 10.0% by mass or less.

The content of the organic acid used in the flux (F7) relative to the total mass of the flux (F7) is preferably 0.1% by mass to 15% by mass, and more preferably 0.2% by mass to 10% by mass.

Relative to the total mass of the flux (F7), the flux (F7) preferably contains 15% by mass or more and 70% by mass or less of at least one resin component selected from the group consisting of rosin-based resins and acrylic resins , It is particularly preferable to contain 35% by mass or more and 60% by mass or less relative to the total mass of the flux (F7).

Examples of the solvent used in the flux (F7) include water, alcohol-based solvents, glycol ether-based solvents, and terpineols.

The flux (F7) may further contain resin components other than rosin-based resins and acrylic resins, amines, halogen-based activators, surfactants, antioxidants, and the like.

By combining the above-mentioned flux (F7) and solder powder containing any one of solder alloys (S1) to solder alloys (S5), it is possible to provide a viscosity increase and other changes over time such as excellent wettability. It has high mechanical properties and is not easy to produce slump-in-print and slump-in-heat solder paste.

In addition, according to the flux (F7), it is possible to provide a solder paste that is not easy to produce the sag of the solder after printing called the printing sag or the sag of the solder when the solder is melted by heating called the heating sag. Flux.

Flux (F8):

The flux (F8) is a composition containing a sorbitol-based thixotropic agent which is a sorbitol compound.

Examples of the flux (F8) include those containing the aforementioned sorbitol-based thixotropic agent which is a sorbitol compound, a rosin-based resin, and a solvent.

Examples of the sorbitol-based thixotropic viscosity reducer (sorbitol compound) include dibenzylidene sorbitol, bis(4-methylbenzylidene)-D-sorbitol, and the like.

The content of the sorbitol-based thixotropic viscosity reducing agent relative to the total mass of the flux (F8) is preferably 0.2% by mass or more, more preferably 0.5% by mass or more, and more preferably 0.5% by mass or more and 5.0% by mass or less. Preferably, it is 0.5% by mass or more and 3.5% by mass or less.

The thixotropic viscosity reducer used in the flux (F8) of this embodiment type can also be used in combination with thixotropic viscosity reducers other than the aforementioned sorbitol-based thixotropic viscosity reducer.

Examples of the thixotropic agent other than the sorbitol-based thixotropic agent include sorbitol-based additives and other thixotropic agents.

Examples of sorbitol-based additives include (D-)sorbitol, monobenzylidene (-D-)sorbitol, mono(4-methylbenzylidene)-(D-)sorbitol, and the like.

The content of the sorbitol-based additive relative to the total mass of the flux (F8) is preferably more than 0% by mass and 0.035% by mass or less, and more preferably 0.00025% by mass or more and 0.035% by mass or less.

Other thixotropic agents may include at least one selected from the group consisting of wax-based thixotropic agents and amide-based thixotropic agents (amide compounds).

Examples of wax-based thixotropic agents belonging to other thixotropic agents include ester compounds, and specific examples include castor oil.

Examples of the amide-based thixotropic agent (amide compound) that are other thixotropic viscosity reducers include the aforementioned polyamides, bisamides, and monoamides.

The content of the other thixotropic viscosity reducing agent relative to the total mass of the flux (F8) is preferably 0.5 to 15.0% by mass, and more preferably 1% by mass to 10% by mass.

Relative to the total mass of the flux (F8), the flux (F8) of this embodiment preferably contains a total of 2% by mass to 15% by mass of a sorbitol-based thixotropic viscosity reducing agent and other tremor reducing viscosity The total mass of the flux (F8) is preferably 2.5% by mass or more and 11.5% by mass or less in total.

The flux (F8) of this embodiment preferably contains the total amount of the thixotropic viscosity reducing agent of 2% by mass or more and 15% by mass relative to the total mass of the flux (F8), and more preferably 2.5% by mass or more 11.5 mass% or less.

The thixotropic viscosity-reducing agent of the flux (F8) of this embodiment is preferably used in combination: selected from the group consisting of dibenzylidene sorbitol and bis(4-methylbenzylidene)-D-sorbitol At least one type of sorbitol-based thixotropic agent in the constituted group, and other thixotropic agents. Thereby, in addition to imparting thixotropic viscosity reduction, it is also easy to suppress the precipitation of crystals and the occurrence of agglomeration in the flux and the solder paste using it.

The thixotropy reducing agent of the flux (F8) of this embodiment is preferably a combination of the aforementioned sorbitol-based thixotropic reducing agent and the aforementioned sorbitol-based additive.

Particularly preferred thixotropic viscosity reducing agents include: the aforementioned sorbitol thixotropic viscosity reducing agent, and selected from (D-) sorbitol, monobenzylidene (-D-) sorbitol and mono(4-methyl) At least one of the aforementioned sorbitol-based additives from the group consisting of (benzylidene)-(D-)sorbitol.

The ratio (mass ratio) of the aforementioned sorbitol-based additive relative to the aforementioned sorbitol-based thixotropic agent is preferably 0.03 to 1.50, particularly preferably 0.05 to 1.00.

In addition, the thixotropic reducer of the flux (F8) of this embodiment is preferably combined with the aforementioned sorbitol-based thixotropic reducer, the aforementioned sorbitol-based additive, and the aforementioned other thixotropic reducer.

The flux (F8) preferably contains 15% to 70% by mass relative to the total mass of the flux (F8), and preferably contains 35% by mass relative to the total mass of the flux (F8). Above 60% by mass or less.

Examples of the solvent used for the flux (F8) include water, alcohol-based solvents, glycol ether-based solvents, and terpineols.

The flux (F8) may further contain resin components other than a thixotropic agent, a rosin-based resin, and a solvent, and examples thereof include organic acids, amines, halogen-based activators, surfactants, and antioxidants.

By combining the above-mentioned flux (F8) with solder powder containing any one of solder alloy (S1) to solder alloy (S5), it is possible to provide a viscosity increase that does not easily cause changes over time, such as an increase in viscosity, and has excellent wettability. Solder paste with high mechanical properties, good fluidity and shape retention.

In addition, according to the flux (F8), it is possible to provide a flux for solder paste that can impart sufficient thixotropic viscosity reduction, preferably suppresses the precipitation of crystals, and is less likely to cause agglomeration.

In addition, the supply of solder paste to the electrodes of the printed circuit board is usually performed by dispensing discharge or screen printing. Therefore, the solder paste is required to have printing properties such as ejection and release, and moreover, it must maintain its shape after being supplied. In solder paste, it has both fluidity (low viscosity) during discharge and printing and flow characteristics (thixotropic viscosity reduction) after supplying shape retention (high viscosity). In recent years, high density has continued to advance. The fine pitch printing in the substrate surface assembly becomes an important factor.

Flux (F9):

The flux (F9) is a composition having both a glycol solvent and an organic acid ester.

Examples of the flux (F9) include those containing a resin component, a solvent, and various active ingredients. Preferable flux (F9) includes those containing rosin-based resin, organic acid, and glycol-based solvents and organic acid esters as solvents.

Rosin-based resins that can be used in flux (F9) include, for example, natural rosin such as gum rosin, wood rosin, or its derivatives (polymerized rosin, hydrogenated rosin, disproportionated rosin, acid-modified rosin, rosin ester, etc. ).

The content of the rosin-based resin in the flux (F9) is not particularly limited. For example, relative to the total mass of the flux (F9), it is preferably in the range of 10 to 80% by mass, particularly preferably in the range of 20 to 70% by mass. Within, more preferably within the range of 30 to 60% by mass.

The content of the organic acid in the flux (F9) is not particularly limited. For example, relative to the total mass of the flux (F9), it is preferably in the range of 1 to 15% by mass, particularly preferably in the range of 3 to 10% by mass. .

In the flux (F9) of this embodiment, the solvent has at least a diol solvent and an organic acid ester. The boiling point of this organic acid ester is in a moderate range. At the bonding temperature used in general soldering, it remains in the flux at the initial stage of bonding and keeps the flux's melt viscosity low. It is easy to release decomposition gas, etc. It is volatilized to a certain extent in the late stage of joining.

The term "diol-based solvent" here means a diol (a compound having a structure in which two different carbon atoms of an aliphatic or alicyclic hydrocarbon are each bonded to a hydroxyl group) or its derivatives. Solvent.

In the flux (F9) of this embodiment, the type of glycol solvent is not particularly limited. For example, fluxes generally used for soldering can be used. Specific examples of glycol-based solvents include diethylene glycol, dipropylene glycol, triethylene glycol, hexanediol, phenyl glycol, hexyl diethylene glycol, and 2-ethylhexyl diethylene glycol: Diethylene glycol monobutyl ether (butyl carbitol), diethylene glycol monomethyl ether (methyl carbitol), diethylene glycol monohexyl ether (hexyl carbitol), propylene glycol monophenyl ether, etc. Glycol ethers.

Among these, preferred are glycol ethers having 2 to 24 carbon atoms (specifically, monoglycol ether (carbon number: 4 to 26), diethylene glycol ether (carbon number: 6 to 28), and oligomeric diglycol ether). Alcohol ether (carbon number: 2+2×n to 24+2×n), particularly preferably a glycol ether of an alcohol having a carbon number of 4 to 16, and particularly preferably a glycol ether of an alcohol having a carbon number of 6 to 8.

The diol-based solvent may be used alone or in combination of two or more.

The content of the diol-based solvent in the flux (F9) (the total content in the case of using multiple diol-based solvents) is not particularly limited, for example, it is preferably 10 relative to the total mass of the flux (F9) It is in the range of 60% by mass to 60% by mass, more preferably in the range of 15 to 50% by mass, and more preferably in the range of 20 to 45% by mass.

In this embodiment, in addition to the above-mentioned glycol-based solvents, organic acid esters may also be used as a solvent in combination. In this way, a flux with low melt viscosity can be realized during soldering.

The flux containing organic acid ester can inhibit the reaction of the solder alloy powder and the activator during the storage of the solder paste. Therefore, even if the activation degree or the blending amount of the activator is not adjusted, its activity can remain, which can ensure the soldering performance. Good wettability and suppress the generation of voids.

Examples of organic acid esters include: dimethyl adipate, diisopropyl adipate, dibutyl maleate, dimethyl sebacate, diisobutyl adipate, sebacic acid Diethyl, diisopropyl sebacate, dibutyl sebacate, dioctyl sebacate, etc. These can be used individually by 1 type or in mixture of multiple types.

The content of the organic acid ester in the flux (F9) (the total content in the case of using multiple organic acid esters) is not particularly limited, and it is preferably 0.5% by mass or more relative to the total mass of the flux (F9) , Particularly preferably 1% by mass or more, more preferably 5% by mass or more. On the other hand, from the viewpoint of eliminating poor drying of the flux or solder paste and suppressing sticking, the content is preferably less, preferably, for example, 30% by mass or less, particularly preferably 25% by mass or less, and more preferably 20% by mass or less, particularly preferably 15% by mass or less.

In addition, the mass ratio of the content (mass%) of the organic acid ester relative to the content (mass%) of the glycol-based solvent (the total amount in the case of using more than one type) (content of organic acid ester/diol-based solvent) The content) is not particularly limited. From the viewpoint of preventing the generation of voids, it is preferably 0.01 to 1.25, particularly preferably 0.10 to 1.0, more preferably 0.15 to 0.75, and particularly preferably 0.15 to 0.50.

In the flux (F9) of this embodiment, in addition to glycol-based solvents and organic acid esters, other commonly known solvents can also be used in combination.

The solvent includes, for example, alcohols such as benzyl alcohol, ethanol, isopropanol, butanol, 1,5-pentanediol, octanediol, terpineol, ethyl cellophane, and butyl cellophane ; Toluene, xylene, n-hexane and other hydrocarbons, one or two or more of these can be used.

The content of the solvent in the flux (F9) of this embodiment is preferably in the range of 20 to 70% by mass, more preferably in the range of 25 to 60% by mass, relative to the total mass of the flux (F9). It is preferably in the range of 30 to 60% by mass.

The flux (F9) of this embodiment can contain resin components other than rosin-based resins, thixotropic viscosity reducers, amines, halogen-based activators, surfactants, and antioxidants.

By combining the above-mentioned flux (F9) with solder powder containing any one of solder alloys (S1) to solder alloys (S5), it is possible to provide a viscosity increase that does not easily cause changes over time, such as an increase in viscosity, and has excellent wettability. It has high mechanical properties and can achieve solder paste with less voids without compromising manufacturing efficiency or storage stability.

In addition, according to the flux (F9), it is possible to provide a flux for solder paste that can achieve soldering with less voids without compromising manufacturing efficiency or storage stability.

Flux (F10):

The flux (F10) is a composition containing a glycol solvent and a monohydric alcohol with 16 to 18 carbon atoms.

The flux (F10) includes resin components, solvents, and various active ingredients. Preferable flux (F10) includes rosin-based resins, organic acids, glycol-based solvents as solvents, and monohydric alcohols with 16 to 18 carbons.

Rosin-based resins that can be used in flux (F10) include, for example, natural rosin such as gum rosin, wood rosin, or its derivatives (polymerized rosin, hydrogenated rosin, disproportionated rosin, acid-modified rosin, rosin ester, etc. ).

The content of the rosin-based resin in the flux (F10) is not particularly limited. For example, relative to the total mass of the flux (F10), it is preferably in the range of 10 to 80% by mass, particularly preferably in the range of 20 to 70% by mass. Within, more preferably within the range of 30 to 60% by mass.

The content of the organic acid in the flux (F10) is not particularly limited. For example, relative to the total mass of the flux (F10), it is preferably in the range of 1 to 15% by mass, particularly preferably in the range of 3 to 10% by mass. .

In the flux (F10) of this embodiment, the solvent has at least a diol-based solvent and a monoalcohol with 16 to 18 carbon atoms. The boiling point of the monohydric alcohol with this carbon number is in a moderate range. At the bonding temperature used in general soldering, it remains in the flux at the initial stage of bonding and keeps the flux's melt viscosity low, which easily releases decomposition gas, etc. And it volatilizes to a certain extent in the late joining period.

The diol-based solvent here means a solvent composed of a diol (a compound having a structure in which two different carbon atoms of an aliphatic or alicyclic hydrocarbon are each bonded to a hydroxyl group) or a derivative thereof.

In the flux (F10) of this embodiment, the type of glycol-based solvent is not particularly limited. For example, fluxes generally used for soldering can be used. Specific examples of glycol-based solvents include diethylene glycol, dipropylene glycol, triethylene glycol, hexanediol, phenyl glycol, hexyl diethylene glycol, and 2-ethylhexyl diethylene glycol: Diethylene glycol monobutyl ether (butyl carbitol), diethylene glycol monomethyl ether (methyl carbitol), diethylene glycol monohexyl ether (hexyl carbitol), propylene glycol monophenyl ether, etc. Glycol ethers.

Among these, preferred are glycol ethers having 2 to 24 carbon atoms (specifically, monoglycol ether (carbon number: 4 to 26), diethylene glycol ether (carbon number: 6 to 28), and oligomeric diglycol ether). Alcohol ether (carbon number: 2+2×n to 24+2×n), particularly preferably a glycol ether of an alcohol having a carbon number of 4 to 16, and particularly preferably a glycol ether of an alcohol having a carbon number of 6 to 8.

The diol-based solvent may be used alone or in combination of two or more.

The content of the diol-based solvent in the flux (F10) (the total content in the case of using multiple diol-based solvents) is not particularly limited, for example, it is preferably 10 relative to the total mass of the flux (F10) It is in the range of 60% by mass to 60% by mass, more preferably in the range of 15 to 50% by mass, and more preferably in the range of 20 to 45% by mass.

In the flux (F10) of this embodiment, in addition to the above-mentioned glycol-based solvent, a monohydric alcohol having 16 to 18 carbon atoms may also be used in combination as a solvent. In this way, a flux with low melt viscosity can be realized during soldering.

Monohydric alcohols with carbon numbers 16 to 18 include: 1-hexadecanol (carbon number 16), 2-hexadecanol (carbon number 16), isocetyl alcohol (carbon number 16), 1-heptadecanol ( Carbon number 17), 1-octadecyl alcohol (carbon number 18), isostearyl alcohol (carbon number 18). Only one type or two or more types may be used in combination.

Among them, those with 16 carbon atoms are preferred, and 2-hexadecanol (CAS number: 2425-77-6) is particularly preferred because it has less viscosity. For 2-hexadecanol, Fineoxocol 1600 (manufactured by Nissan Chemical Industry Co., Ltd., registered trademark) or the like can be used, for example.

The content of the monohydric alcohol with 16 to 18 carbons in the flux (F10) is not particularly limited, as long as the monohydric alcohol with 16 to 18 carbons is contained in the flux (F10).

From the point of view of reducing the melt viscosity of the flux or solder paste during soldering, the higher the content of the monoalcohols with carbon numbers of 16 to 18 in the flux (F10), the better, for example, 0.5% by mass or more. More preferably, it is 1% by mass or more, and more preferably is 5% by mass or more.

On the other hand, from the point of view of eliminating poor drying of flux or solder paste and suppressing sticking, the less content of monoalcohols with carbon numbers of 16 to 18 in the flux (F10) is the better, for example, the better is 30% by mass or less, more preferably 20% by mass or less, and more preferably 15% by mass or less.

In addition, the mass ratio of the content (mass%) of the monohydric alcohol having 16 to 18 carbons to the content (mass%) of the glycol-based solvent (the total amount in the case of using more than one type) (carbon numbers 16 to 18 The content of the monohydric alcohol/the content of the glycol-based solvent) is not particularly limited, but from the viewpoint of the balance of prevention of void generation and drying, it is preferably 0.01 to 1.25, particularly preferably 0.15 to 1.25, and more preferably 0.15 To 0.72.

In the flux (F10) of this embodiment, in addition to glycol solvents and monohydric alcohols with 16 to 18 carbons, other commonly known solvents can also be used in combination.

The solvent includes, for example, alcohols such as benzyl alcohol, ethanol, isopropanol, butanol, 1,5-pentanediol, octanediol, terpineol, ethyl cellophane, and butyl cellophane ; Hydrocarbons such as toluene, xylene, n-hexane; esters such as isopropyl acetate, butyl benzoate, etc., one or two or more of these can be used.

The content of the solvent in the flux (F10) of this embodiment is preferably in the range of 20 to 70% by mass, more preferably in the range of 25 to 60% by mass, relative to the total mass of the flux (F10). It is preferably in the range of 30 to 55% by mass.

The flux (F10) of this embodiment can contain resin components other than rosin-based resins, thixotropic viscosity reducers, amines, halogen-based activators, surfactants, and antioxidants.

By combining the above-mentioned flux (F10) and solder powder containing any one of solder alloy (S1) to solder alloy (S5), it is possible to provide a viscosity increase and other changes over time such as excellent wettability. It has high mechanical properties and can achieve solder paste with less voids without compromising manufacturing efficiency or storage stability.

In addition, according to the flux (F10), it is possible to provide a flux for solder paste that can achieve soldering with less voids without compromising manufacturing efficiency or storage stability.

Flux (F11):

The flux (F11) is a composition containing hindered phenolic compounds.

The flux (F11) includes, for example, a resin component containing a hindered phenol-based compound, an organic acid, and at least one resin component selected from the group consisting of a rosin-based resin and an acrylic resin, and a solvent.

The flux (F11) contains hindered phenolic compounds as metal deactivators. By making the flux contain hindered phenolic compounds, the effect of suppressing the increase in viscosity can be achieved in the solder paste.

The term "hindered phenol-based compound" means a phenol-based compound in which at least one of the ortho positions of the phenol has a relatively large substituent (for example, branched or cyclic alkyl groups such as tertiary butyl).

The hindered phenol compound is not particularly limited. For example, bis[3-(3-tertiarybutyl-4-hydroxy-5-methylphenyl)propionic acid][ethylene bis(oxyethylene)], N,N'-hexamethylenebis[3-(3,5-bis(tertiary butyl)-4-hydroxyphenyl)propane amide], 1,6-hexanediol bis[3-(3 ,5-bis(tertiarybutyl)-4-hydroxyphenyl)propionate], 2,2'-methylenebis[6-(1-methylcyclohexyl)-p-cresol], 2, 2'-methylene bis(6-tertiary butyl-p-cresol), 2,2'-methylene bis(6-tertiary butyl-4-ethylphenol), triethylene glycol-bis[ 3-(3-tertiary butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol bis[3-(3,5-bis(tertiary butyl)- 4-hydroxyphenyl)propionate), 2,4-bis(n-octylsulfide)-6-(4-hydroxy-3,5-bis(tertiarybutyl)anilino)-1,3,5 -Triazine, neopentylerythritol-tetra[3-(3,5-bis(tertiarybutyl)-4-hydroxyphenyl)propionate], 2,2-sulfur-divinylbis[3- (3,5-bis(tertiary butyl)-4-hydroxyphenyl)propionate), octadecyl-3-3-(3,5-bis(tertiary butyl)-4-hydroxyphenyl ) Propionate, N,N'-hexamethylene bis(3,5-bis(tertiary butyl)-4-hydroxy-hydrocinnamamide), 3,5-bis(tertiary butyl)- 4-Hydroxybenzylphosphonate-diethyl, 1,3,5-trimethyl-2,4,6-tris(3,5-bis(tertiarybutyl)-4-hydroxybenzyl )Benzene, N,N'-bis[2-[2-(3,5-bis(tertiarybutyl)-4-hydroxyphenyl)ethylcarbonyloxy]ethyl]oxamide, in the following formula (2) The compound etc. represented.

In this formula, Z is a substituted alkylene; R ⁵ and R ⁶ are each independently a substituted alkyl, aralkyl, aryl, heteroaryl, cycloalkyl or heterocycloalkyl group; R ⁷ and R ⁸ are each independently an alkyl group which may be substituted.

The above-mentioned hindered phenol-based compounds can be used singly or in combination of two or more kinds.

The content of the hindered phenol-based compound is preferably 0.5 to 10% by mass relative to the total mass of the flux (F11). By making the content 0.5% by mass or more, the solder paste can further enhance the effect of suppressing the increase in viscosity. By making the content 10% by mass or less, the solder paste can further improve solder wettability. From the same viewpoint, the content is particularly preferably 1.0 to 5.0% by mass relative to the total mass of the flux (F11), and more preferably 2.0 to 4.0% by mass relative to the total mass of the flux (F11).

The content of the organic acid used in the flux (F11) is preferably 0.1% by mass to 15% by mass relative to the total mass of the flux (F11), and more preferably 0.2% by mass relative to the total mass of the flux (F11) Above 10% by mass.

Relative to the total mass of the flux (F11), the flux (F11) preferably contains 15% by mass or more and 70% by mass or less of at least one resin component selected from the group consisting of rosin resins and acrylic resins It is particularly preferable to contain 20% by mass or more and 60% by mass or less relative to the total mass of the flux (F11).

Examples of the solvent used for the flux (F11) include water, alcohol-based solvents, glycol ether-based solvents, and terpineols.

The flux (F11) may further contain resin components other than rosin resin and acrylic resin, thixotropic viscosity reducer, amine, halogen-based activator, surfactant, and antioxidant.

By combining the above-mentioned flux (F11) with solder powder containing any one of solder alloy (S1) to solder alloy (S5), it is possible to provide a viscosity increase and other changes over time such as excellent wettability. Solder paste with high mechanical properties and improved reliability.

In addition, according to the flux (F11), it is possible to provide a flux for solder paste that can have both the viscosity suppression effect, reliability, and wettability of the solder paste at the same time in a well-balanced manner.

Flux (F12):

Flux (F12) is a composition containing a metal deactivator which is a nitrogen compound.

The flux (F12) includes, for example, a metal deactivator belonging to a nitrogen compound, a resin component selected from at least one resin component selected from the group consisting of a rosin-based resin and an acrylic resin, and a solvent.

Flux (F12) contains nitrogen compounds as metal deactivators. By making the flux contain a metal deactivator belonging to a nitrogen compound, the effect of suppressing the increase in viscosity can be achieved in the solder paste.

The nitrogen compound is not particularly limited as long as it has a nitrogen atom and is used as a metal deactivator. From the viewpoint of excellent viscosity increasing inhibitory effect, the nitrogen compound here is preferably selected from the group consisting of Hydrazide-based nitrogen compounds, amide-based nitrogen compounds, triazole-based nitrogen compounds, and melamine-based nitrogen compounds. At least one nitrogen compound in the constituted group is particularly preferably at least one selected from the group consisting of hydrazine-based nitrogen compounds and triazole-based nitrogen compounds.

The hydrazine-based nitrogen compound may be a nitrogen compound having a hydrazine skeleton, and examples thereof include dodecanedioic acid bis[N2-(2-hydroxybenzyl)hydrazine], N,N'-bis[3 -(3,5-bis(tertiary butyl)-4-hydroxyphenyl)propionyl)hydrazine, decane dicarboxylic acid bis-salicylic hydrazine, N-salicylidene-N'-salicylic hydrazine, M-Nitrobenzyl hydrazine, 3-aminophthalic hydrazine, dihydrazine phthalate, hydrazine adipic acid, oxalyl bis(2- Hydroxy-5-octylbenzylidene hydrazine), N'-benzylpyrrolidone hydrazine carboxylate, N,N'-bis(3-(3,5-bis(tertiary butyl)) -4-Hydroxyphenyl)propionyl)hydrazine and the like.

The amide-based nitrogen compound may be a nitrogen compound having an amide skeleton, and examples thereof include: N,N'-bis{2-[3-(3,5-di(tertiarybutyl)-4-hydroxybenzene Yl)propanyloxy]ethyl}glazamide and the like.

The triazole-based nitrogen compound may be a nitrogen compound having a triazole skeleton, and examples thereof include N-(2H-1,2,4-triazol-5-yl)salanamide, 3-amino-1, 2,4-triazole, 3-(N-salicylic)amino-1,2,4-triazole, etc.

The melamine-based nitrogen compound may be a nitrogen compound having a melamine skeleton, and melamine, melamine derivatives, and the like can be mentioned.

More specifically, for example, triaminotriazine, alkylated triaminotriazine, alkoxyalkylated triaminotriazine, melamine, alkylated melamine, alkoxyalkylated Melamine, N2-butyl melamine, N2,N2-diethyl melamine, N,N,N',N',N",N"-hexa(methoxymethyl)melamine, etc.

In addition, commercially available products can be used for the melamine-based nitrogen compound, and examples include ADK STAB ZS-27 and ZS-90 manufactured by ADEKA Corporation, and ADK STAB ZS-27 is particularly preferred. These specific commercially available products are preferable from the viewpoint that the thickening suppression effect is more pronounced.

The said nitrogen compound can be used individually by 1 type or in combination of 2 or more types.

The content of the nitrogen compound relative to the total mass of the flux (F12) is preferably more than 0% by mass and 10% by mass or less, more preferably 0.05 to 5.0% by mass, more preferably 0.10 to 2.0% by mass, and particularly preferably 0.10 To 1.0% by mass. By making the content more than 0% by mass, the effect of suppressing thickening of the solder paste becomes excellent.

In the flux (F12), in addition to the above-mentioned nitrogen compounds, hindered phenolic compounds may be used in combination as a metal deactivator.

By using hindered phenolic compounds as the metal deactivator, the viscosity increase suppression effect of the solder paste will be more excellent.

The hindered phenol-based compound is not particularly limited. For example, the same hindered phenol-based compound as exemplified in the description of the flux (F11) can be mentioned.

The content of the hindered phenol compound relative to the total mass of the flux (F12) is preferably, for example, 0 to 10% by mass, particularly preferably 1 to 10% by mass, and more preferably 2 to 10% by mass.

Relative to the total mass of the flux (F12), the flux (F12) preferably contains 15% by mass or more and 70% by mass or less of at least one resin component selected from the group consisting of rosin resins and acrylic resins It is particularly preferable to contain 35% by mass or more and 60% by mass or less relative to the total mass of the flux (F12).

Examples of the solvent used for the flux (F12) include water, alcohol-based solvents, glycol ether-based solvents, and terpineols.

The flux (F12) may further contain organic acids.

The content of the organic acid used in the flux (F12) is preferably 0.1% by mass to 15% by mass relative to the total mass of the flux (F12), and more preferably 0.2% by mass relative to the total mass of the flux (F12) Above 10% by mass or less, more preferably 1% by mass or more and 8% by mass or less.

The flux (F12) may further contain resin components other than rosin-based resin and acrylic resin, thixotropic viscosity reducer, amine, halogen-based activator, surfactant, and antioxidant.

By combining the above-mentioned flux (F12) and solder powder containing any one of solder alloy (S1) to solder alloy (S5), it is possible to provide a viscosity increase and other changes over time such as excellent wettability. Solder paste with high mechanical properties and improved reliability.

In addition, according to the flux (F12), it is possible to provide a flux for solder paste that has a good balance and has the effect of suppressing viscosity increase, reliability, and wettability of the solder paste.

The solder paste of the present invention described above is suitable for bonding an IC chip and its substrate (intermediary substrate) used in a semiconductor package, or bonding a semiconductor package and a printed circuit board.

The joining method using the solder paste of the present invention can be carried out by using a reflow method and following a common method, for example. In the case of flow soldering, the melting temperature of the solder alloy can be approximately 20°C higher than the liquidus temperature. In addition, in the case of joining using the solder alloy of this embodiment, it is preferable to consider the cooling rate during solidification from the viewpoint of microstructure. For example, the solder joint is cooled at a cooling rate of 2 to 3°C/s or more. Other joining conditions can be adjusted appropriately according to the alloy composition of the solder alloy.

The solder alloy of this embodiment can be used to manufacture low-alpha-radiation alloys by using low-alpha-radiation materials as its raw materials. This low alpha dose alloy can suppress software errors when used in the formation of solder bumps around the memory.

The solder paste of this embodiment preferably further contains zirconia powder. By containing zirconia, it is possible to suppress the increase in the viscosity of the solder paste due to changes over time. This is presumably because the oxide film thickness on the surface of the solder powder is maintained at the state before the flux is added by containing zirconia. Although the detailed mechanism is not clear, it can be speculated as follows. Generally, the active components of the flux have a little activity even at room temperature, so the surface oxide film of the solder powder will become thin due to the reduction, which causes the powders to agglomerate with each other. Therefore, by adding the zirconia powder to the solder paste, the active components of the flux preferentially react with the zirconia powder, so that the oxide film on the surface of the solder powder is maintained at a level that does not aggregate.

In order to fully exert this effect, the content of the zirconia powder in the solder paste is preferably 0.05 to 20.0% by mass relative to the total mass of the solder paste. When it is 0.05% by mass or more, it can be used When the above-mentioned effect is 20.0% by mass or less, the content of the metal powder can be secured and the effect of suppressing the increase in viscosity can be exhibited. The content of the zirconia powder is particularly preferably 0.05 to 10.0% by mass, and more preferably 0.1 to 3% by mass.

The particle size of the zirconia powder in the solder paste is preferably 5 μm or less. When the particle size is 5 μm or less, the printability of the paste can be maintained. The lower limit of the particle size is not particularly limited, and may be 0.5 μm or more.

The particle size of the above-mentioned zirconia powder is obtained by taking a SEM photograph of the zirconia powder, and calculating the equivalent diameter of the projected circle for each powder of 0.1 μm or more by image analysis, and setting it as an average value.

The shape of the zirconia powder is not particularly limited, but if it is a specific shape, the contact area with the flux is increased and the effect of suppressing the increase in viscosity is increased. When it is a real ball, good fluidity can be obtained, so excellent printability as a paste can be obtained. The appropriate shape can be selected according to the desired characteristics.

〈Flux for solder paste〉

The flux for solder paste of this embodiment is used for solder paste using the above-mentioned specific solder powder. The flux preferably contains a resin component, an active component, and a solvent.

The solder paste flux of this embodiment uses a specific solder powder, that is, a solder powder containing a solder alloy, which is suitable for use in solder paste. The solder alloy has: As: 10 mass ppm or more and no Up to 40 mass ppm, and at least one of Bi: 0 to 25,000 mass ppm and Pb: 0 to 8,000 mass ppm, and the remainder is an alloy composition composed of Sn, and satisfies the following formulas (1) and (2) formula,

300≦3As+Bi+Pb (1)

0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2)

In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition.

In addition, the solder paste flux of this embodiment uses a specific solder powder, that is, a solder powder containing a solder alloy, which is suitable for use in solder paste, and the solder alloy has: As: 10 mass ppm or more And less than 40 mass ppm, and Bi: more than 0 mass ppm and less than 25,000 mass ppm, and Pb: more than 0 mass ppm and at least one of 8000 mass ppm or less, and the remainder is an alloy composition composed of Sn, And satisfies the following formula (1) and (2),

300≦3As+Bi+Pb (1)

0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2)

In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition.

In the solder paste that combines the solder paste flux of this embodiment with the above-mentioned specific solder powder, it is unlikely to cause changes over time such as an increase in viscosity, has excellent wettability, and exhibits high mechanical properties. Furthermore, according to the solder paste combining this solder paste flux with the aforementioned specific solder powder, by selecting the components blended in the flux, the wetting speed of the solder can be further improved and the metal surface of the joining object can be further improved. (E.g. copper plate) corrosion inhibition, printability improvement, void suppression and other various characteristics.

[Example]

The following examples illustrate the present invention in more detail, but the present invention is not limited to these examples.

Production of solder powder:

First make: solder powder (test example) having the alloy composition shown in Table 1 to Table 14, and in the powder size classification of JIS Z 3284-1:2014 (Table 2) (Table 2) 1 to 258, test examples 301 to 354).

Preparation of flux (F0):

Rosin is used as the resin component.

Use thixotropic viscosity reducers, organic acids, amines and halogen-based active agents as active ingredients.

A glycol-based solvent is used as the solvent.

42 parts by mass of rosin, 35 parts by mass of glycol solvent, 8 parts by mass of thixotropic agent, 10 parts by mass of organic acid, 2 parts by mass of amine, and 3 parts by mass of halogen-based activator were mixed to prepare flux (F0).

The flux (F0) prepared above and the solder powder having the alloy composition of each example shown in Table 1 to Table 14 were mixed to prepare a solder paste. The mass ratio of flux (F0) to solder powder is set as flux (F0): solder powder=11:89.

In the case of using the solder powder of each example, the viscosity in the solder paste was measured over time. In addition, the liquidus temperature and solidus temperature of the solder powder are measured. Furthermore, the wettability evaluation was performed using the solder paste just produced. The details are as follows.

<Evaluation of the change of viscosity in solder paste over time>

(1) Verification method

Using PCU-205 manufactured by Malcom Co., Ltd., the viscosity of each solder paste just produced was measured for 12 hours at a rotation speed of 10 rpm, 25° C., and the atmosphere.

(2) Judgment criteria

A: The viscosity after 12 hours is 1.2 times or less compared to the viscosity after 30 minutes after the solder paste is produced.

B: The viscosity after 12 hours was more than 1.2 times the viscosity after 30 minutes had passed after the solder paste was produced.

<Assessment of △T>

(1) Verification method

Use SII Nano Technology Co., Ltd., model: EXSTAR DSC7020, sample size: about 30mg, heating rate: 15℃/min, perform DSC measurement on solder powder before mixing with flux (F0) to obtain liquidus Temperature and solidus temperature. Subtract the solidus temperature from the obtained liquidus temperature to obtain ΔT.

(2) Judgment criteria

A: ΔT is 10°C or less.

B: ΔT exceeds 10°C.

<Assessment of wettability>

(1) Verification method

Each solder paste just produced was printed on a Cu board, heated from 25°C to 260°C at a temperature increase rate of 1°C/s _{in a N 2 gas atmosphere in a reflow furnace, and then cooled to room temperature.} Observe the appearance of the solder bumps after cooling with an optical microscope to evaluate the wettability.

(2) Judgment criteria

A: The solder powder that was not completely melted was not observed.

B: Incompletely molten solder powder is observed.

<Comprehensive Evaluation>

A: In Tables 1 to 14, the evaluations of changes over time, ΔT, and wettability are all A.

B: In Tables 1 to 14, at least one of the evaluations of changes over time, ΔT, and wettability is B.

The evaluation results are shown in Table 1 to Table 14. In Table 12 to Table 14, the bottom line indicates outside the scope of the present invention.

[Table 1]

[Table 2]

[table 3]

[Table 4]

[table 5]

[Table 6]

[Table 7]

[Table 8]

[Table 9]

[Table 10]

[Table 11]

[Table 12]

[Table 13]

[Table 14]

As shown in Tables 1 to 14, in the solder paste containing the solder powder with the alloy composition of Test Examples 1 to 258 and the flux (F0), any alloy composition satisfies the requirements of the present invention, so it can It was confirmed that it exhibits an excellent viscosity-increasing suppression effect, narrowing of ΔT, and excellent wettability.

These solder pastes containing solder powder having the alloy composition of Test Examples 1 to 258 and flux (F0) are solder pastes applicable to the embodiments of the present invention.

On the other hand, in the solder paste containing the solder powder having the alloy composition of Test Examples 301 to 354, and the flux (F0), none of the alloy compositions satisfies at least one of the requirements of the present invention, thus showing At least one of the viscosity increasing suppression effect, the narrowing of ΔT, and the excellent wettability is a poor result.

[Evaluation of solder paste containing flux (F1)]

Next, for the solder powder having the alloy composition shown in Test Example 1 using the fluxes of the blending examples (F1-1) to (F1-55) shown in Table 15 to Table 23, the above-mentioned <Solder Paste "Evaluation of the change in viscosity over time". In addition, the above-mentioned <Evaluation of ΔT> was performed by measuring the liquidus temperature and the solidus temperature of the solder powder. In addition, the above-mentioned "Evaluation of wettability" was performed using the solder paste just produced.

From these results, it can be confirmed that the solder pastes in the case of using the fluxes of the blending examples (F1-1) to (F1-55) with respect to the solder powder having the alloy composition shown in Test Example 1 all show It has the effect of suppressing viscosity increase, narrowing of △T and excellent wettability.

Next, for the solder powder having the alloy composition shown in Test Example 1 using the fluxes of the blending examples (F1-1) to (F1-55) shown in Table 15 to Table 23, the solder is wetted Evaluation of speed (solder wettability).

<Assessment of solder wetting speed (solder wettability)>

(1) Verification method

The evaluation test of the solder wetting speed (solder wettability) is carried out in the following manner.

According to the method of the arc-shaped solder dip test (meniscograph test), a copper plate with a width of 5 mm × a length of 25 mm × a thickness of 0.5 mm was oxidized at 150°C for 1 hour to obtain the copper oxide plate of the test board. Solder Checker SAT-5200 ( RHESCA Corporation) was used as the test device, and the solder powder having the alloy composition shown in Test Example 1 was used as the solder, and the evaluation was performed in the following manner.

First, with respect to each of the fluxes of the formulation examples (F1-1) to (F1-55) measured in the beaker, the test board was immersed for 3 mm to apply the flux to the test board. Next, after the flux was applied, the test board coated with the flux was quickly immersed in the solder tank of the alloy composition shown in Test Example 1, and the zero crossing time (sec) was obtained.

Next, the flux of each blending example was measured 5 times, and the average value of the obtained 5 zero crossing times (sec) was calculated. The test conditions are set as follows.

Dipping speed into solder tank: 5mm/sec (JIS Z 3198-4: 2003)

Dipping depth into solder tank: 2mm (JIS Z 3198-4: 2003)

Dipping time into solder tank: 10sec (JIS Z 3198-4: 2003)

Solder bath temperature: 245°C (JIS C 60068-2-69: 2019 Appendix B) The shorter the average value of the zero crossing time (sec), the higher the wetting speed, the better the solder wettability.

(2) Judgment criteria

A: The average value of the zero-crossing time (sec) is 2.5 seconds or less.

B: The average value of the zero crossing time (sec) exceeds 2.5 seconds.

The evaluation results are shown in Table 15 to Table 23.

In the table, aliphatic polyamide is used as polyamide, hexamethylene bishydroxystearylamine is used as bisamide, and p-toluamide is used as monoamide.

[Table 15]

[Table 16]

[Table 17]

[Table 18]

[Table 19]

[Table 20]

[Table 21]

[Table 22]

[Table 23]

In the case of using the fluxes of the blending examples (F1-1) to (F1-54) with respect to the solder powder having the alloy composition shown in Test Example 1, the flux of the blending example (F1-55) is used Compared with the case, it can be confirmed that the solder wetting speed is higher, and the solder wettability is better. Among them, the solder paste containing the solder powder with the alloy composition of Test Example 1 and the fluxes of the blending examples (F1-1) to (F1-54) is the solder paste of the implementation type containing the flux (F1) .

Next, for the solder powders having the alloy compositions shown in Test Examples 2 to 258 and Test Examples 301 to 354, respectively, the fluxes of the formulation examples (F1-1) to (F1-55) are used, and the above-mentioned < Evaluation of the change of viscosity in solder paste over time>, <Evaluation of △T> and <Evaluation of wettability>, and <Evaluation of wetting speed>.

From the results of this evaluation, it can be confirmed that in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 2 to 258, the viscosity increase suppression effect, the narrowing of ΔT, and the excellent wettability are shown. Among them, the solder paste containing each solder powder having the alloy composition of Test Examples 2 to 258 and the fluxes of the blending examples (F1-1) to (F1-54) is the implementation containing the flux (F1) Type of solder paste.

On the other hand, in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 301 to 354, at least one of the viscosity increasing suppression effect, the narrowing of ΔT, and the excellent wettability is poor. result.

In addition, in the case of using the fluxes of the blending examples (F1-1) to (F1-54) with respect to the solder powders of test examples 2 to 258, and using the flux of blending example (F1-55) In comparison, it can be confirmed that the wetting speed of the solder is higher, and the solder wettability is better.

[Evaluation of solder paste containing flux (F2)]

Next, for the solder powder having the alloy composition shown in Test Example 1 using the fluxes of the blending examples (F2-1) to (F2-62) shown in Tables 24 to 36, the above-mentioned <Solder Paste "Evaluation of the change in viscosity over time". In addition, the above-mentioned <Evaluation of ΔT> was performed by measuring the liquidus temperature and the solidus temperature of the solder powder. In addition, the above-mentioned "Evaluation of wettability" was performed using the solder paste just produced.

From these results, it can be confirmed that the solder pastes in the case of using the fluxes of the blending examples (F2-1) to (F2-62) with respect to the solder powder having the alloy composition shown in Test Example 1 all show It has the effect of suppressing viscosity increase, narrowing of △T and excellent wettability.

Next, for the solder powder having the alloy composition shown in Test Example 1 using the fluxes of the blending examples (F2-1) to (F2-62) shown in Table 24 to Table 36, the temperature of the flux was performed Evaluation of cyclic reliability.

<Evaluation of temperature cycle reliability>

(1) Verification method

The evaluation of the reliability of the temperature cycle is to apply the fluxes of the preparation examples (F2-1) to (F2-62) on the Cu board so that the residue is formed on the Cu board. Repeat the process of keeping the residue formed on the Cu plate at -30°C and +110°C for 30 minutes, and perform this test for 500 cycles, and then visually evaluate whether the residue is cracked or not.

(2) Judgment criteria

A: The generation of cracks is not observed in the residue, and the temperature cycle reliability is excellent.

B: The generation of cracks is observed in the residue, and the reliability of the temperature cycle is poor.

The evaluation results are shown in Table 24 to Table 36.

The composition ratios in Tables 24 to 36 are wt (mass)% when the total amount of flux is 100.

In each table, acrylic resin A is poly-2-ethylhexyl acrylate (Mw=8300). Acrylic resin B is poly(2-ethylhexyl acrylate) with different molecular weights (Mw=11700). Acrylic resin C is polylauryl methacrylate (Mw=10080). Acrylic resin D is polyacrylate 2-ethylhexyl-polyethylene (1Mw=12300).

In each table, aliphatic polyamide is used as polyamide, hexamethylene bishydroxystearyl amide is used as bisamide, and p-toluamide is used as monoamide.

[Table 24]

[Table 25]

[Table 26]

[Table 27]

[Table 28]

[Table 29]

[Table 30]

[Table 31]

[Table 32]

[Table 33]

[Table 34]

[Table 35]

[Table 36]

In the case of using the fluxes of the blending examples (F2-1) to (F2-60) with respect to the solder powder having the alloy composition shown in Test Example 1, the blending examples (F2-61) to (F2- 62) of each flux Compared with the situation, it can be confirmed that the generation of cracks in the residue is suppressed, and the reliability of the temperature cycle is improved. Among them, the solder paste containing the solder powder with the alloy composition of Test Example 1 and the fluxes of the blending examples (F2-1) to (F2-60) is the solder paste of the implementation type containing the flux (F2) .

Next, for the solder powders having the alloy compositions shown in Test Examples 2 to 258 and Test Examples 301 to 354, respectively, the fluxes of Blending Examples (F2-1) to (F2-62) were used, and the above-mentioned < Evaluation of the change of viscosity in solder paste over time>, <Evaluation of △T> and <Evaluation of wettability>, and <Evaluation of reliability of temperature cycling>.

From the results of this evaluation, it can be confirmed that in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 2 to 258, the viscosity increase suppression effect, the narrowing of ΔT, and the excellent wettability are shown. Among them, the solder paste containing each solder powder with the alloy composition of Test Examples 2 to 258 and the fluxes of the blending examples (F2-1) to (F2-60) is an implementation that contains flux (F2) Type of solder paste.

On the other hand, in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 301 to 354, at least one of the viscosity increasing suppression effect, the narrowing of ΔT, and the excellent wettability is poor. result.

In addition, in the case of using the fluxes of the blending examples (F2-1) to (F2-60) with respect to the solder powders of test examples 2 to 258, the same as the use of blending examples (F2-61) to (F2-62) Compared with the case of the flux of ), it can be confirmed that the generation of cracks in the residue is suppressed, and the temperature cycle reliability is improved.

[Evaluation of solder paste containing flux (F3)]

Next, for the solder powder having the alloy composition shown in Test Example 1 using the fluxes of the blending examples (F3-1) to (F3-51) shown in Table 37 to Table 44, the above-mentioned <Solder Paste "Evaluation of the change in viscosity over time". In addition, the liquidus temperature and solidus temperature of the solder powder are measured. Perform the above "Assessment of △T". In addition, the above-mentioned "Evaluation of wettability" was performed using the solder paste just produced.

From these results, it can be confirmed that the solder pastes in the case of using the fluxes of the blending examples (F3-1) to (F3-51) with respect to the solder powder having the alloy composition shown in Test Example 1 all show It has the effect of suppressing viscosity increase, narrowing of △T and excellent wettability.

Next, for the solder powder having the alloy composition shown in Test Example 1, the solder paste (assisted) when the fluxes of the blending examples (F3-1) to (F3-51) shown in Table 37 to Table 44 are used Flux: Solder powder = 11:89 mass ratio), and evaluate the wettability of the solder and the dewetting suppression ability of the solder.

〈Assessment of solder wettability and spreadability〉

(1) Verification method

The evaluation test of the wettability of the solder is carried out in the following manner.

According to the predetermined pattern described in JIS Z 3284-3:2014, each solder paste is printed on a Bare-Cu board of 50 mm in length × 50 mm in width × 0.5 mm in thickness using a stainless steel mask formed with the printing part of the solder paste .

The printed part formed on the mask is a quadrangular opening with a size of 3.0mm×1.5mm. In the printing part, a plurality of openings of the same size are arranged at different intervals, and the interval of the openings is 0.2-0.3-0.4-0.5-0.6-0.7-0.8-0.9-1.0-1.1-1.2mm.

Remove the mask after the solder paste is printed. Before reflowing, make sure that the solder paste is not in contact with the minimum distance between the printed parts and perform reflowing. The conditions of the reflow were preheated at 190°C for 120 seconds in an atmospheric environment, and then the heating rate was set to 1°C/sec, and the temperature was increased from 190°C to 260°C to perform main heating.

(2) Judgment criteria

Confirm that the above-mentioned solder paste printed at a predetermined interval wets and expands after reflowing and contacts and fuse (N=4).

A: All the places where the interval L is 0.8 mm or less are fused.

B: Even if the interval L is 0.8 mm or less, there are some unfused parts even in one place.

<Assessment of Dehumidification Suppression Ability of Solder>

(1) Verification method

The evaluation test of the dehumidification suppression ability of the solder is carried out in the following manner.

Each solder paste was printed on a Cu-OSP pad with a length of 0.8 mm × a width of 0.8 mm, and reflow was performed. The printing thickness of the solder paste is set to 0.12 mm. The conditions of the reflow were preheated at 190°C for 120 seconds in an atmospheric environment, and then the heating rate was set to 1°C/sec, and the temperature was increased from 190°C to 260°C to perform main heating.

(2) Judgment criteria

Use an optical microscope to observe the occurrence of poor wetting (dewetting) after reflow (N=12).

A: The parts where the solder paste is applied are all wetted by the solder.

B: Although most of the part where the solder paste is applied is in the state of being wetted by the solder (including dewetting), poor wetting is also caused. Or the appearance of no solder wetting, the molten solder becomes one or more solder balls (non-wetting).

<Comprehensive Evaluation>

A: In Tables 37 to 44, the evaluations of the wetting spreadability and dewetting suppression ability of the solder are all A.

B: In Table 37 to Table 44, at least one item in each evaluation of the wettability spreadability and dewetting suppression ability of the solder is B.

The evaluation results are shown in Table 37 to Table 44.

In the table, aliphatic polyamide is used as polyamide, hexamethylene bishydroxystearylamine is used as bisamide, and p-toluamide is used as monoamide.

[Table 37]

[Table 38]

[Table 39]

[Table 40]

[Table 41]

[Table 42]

[Table 43]

[Table 44]

In the case of using the fluxes of the blending examples (F3-1) to (F3-50) with respect to the solder powder having the alloy composition shown in Test Example 1, the flux of the blending example (F3-51) is used. Compared with the situation, it can be confirmed that the solder has good wettability and spreadability and high dehumidification suppression ability. Among them, the solder paste containing the solder powder with the alloy composition of Test Example 1 and the fluxes of the blending examples (F3-1) to (F3-50) is an implementation type solder paste containing flux (F3) .

Next, for the solder powders having the alloy compositions shown in Test Examples 2 to 258 and Test Examples 301 to 354, each of the fluxes of the blending examples (F3-1) to (F3-51) was used, and the above-mentioned < Evaluation of the change of viscosity in solder paste with time>, <Evaluation of △T> and <Evaluation of wettability>, as well as <Evaluation of solder wettability extension> and <Evaluation of solder dewetting inhibition ability 〉.

From the results of this evaluation, it can be confirmed that in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 2 to 258, the viscosity increase suppression effect, the narrowing of ΔT, and the excellent wettability are shown. Among them, the solder paste containing each solder powder with the alloy composition of Test Examples 2 to 258 and the fluxes of the blending examples (F3-1) to (F3-50) is an implementation that contains flux (F3) Type of solder paste.

On the other hand, in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 301 to 354, at least one of the viscosity increasing suppression effect, the narrowing of ΔT, and the excellent wettability is poor. result.

In addition, in the case of using the fluxes of the blending examples (F3-1) to (F3-50) with respect to the solder powders of test examples 2 to 258, and using the flux of blending example (F3-51) In comparison, it can be confirmed that the wetting and spreading properties of the solder are relatively good, and the dehumidification suppression ability is high.

[Evaluation of solder paste containing flux (F4)]

Next, for the solder powder having the alloy composition shown in Test Example 1 using the fluxes of the blending examples (F4-1) to (F4-58) shown in Table 45 to Table 56, the above-mentioned <Solder Paste "Evaluation of the change in viscosity over time". In addition, the above-mentioned <Evaluation of ΔT> was performed by measuring the liquidus temperature and the solidus temperature of the solder powder. In addition, the above-mentioned "Evaluation of wettability" was performed using the solder paste just produced.

From these results, it can be confirmed that the solder pastes in the case of using the fluxes of the blending examples (F4-1) to (F4-58) with respect to the solder powder having the alloy composition shown in Test Example 1 all show It has the effect of suppressing viscosity increase, narrowing of △T and excellent wettability.

Next, for the solder powder with the alloy composition shown in Test Example 1, the fluxes of the blending examples (F4-1) to (F4-58) shown in Table 45 to Table 56 were used, and the solder was wetted. Evaluation of speed (solder wettability).

<Evaluation of solder wettability (wetting speed) of solder>

(1) Verification method

The flux wetting speed is based on the arc surface dip solder test method. A copper plate with a width of 5 mm × a length of 25 mm × a thickness of 0.5 mm is oxidized at 150°C for 1 hour to obtain the copper oxide plate of the test board. Solder Checker SAT is used -5200 (manufactured by RHESCA) was used as a test device, and solder powder having the alloy composition shown in Test Example 1 was used as the solder, and the evaluation was performed in the following manner.

First, with respect to each flux of the preparation examples (F4-1) to (F4-58) measured in the beaker, the test board was immersed for 5 mm to apply each flux to the test board. Next, after applying the flux, quickly immerse the test board coated with the flux in the solder tank to obtain the zero crossing time (sec). Next, the fluxes of the blending examples (F4-1) to (F4-58) were measured 5 times, and the average value of the obtained 5 zero-crossing times (sec) was calculated. The test conditions are set as follows.

Dipping speed into solder tank: 5mm/sec (JIS Z 3198-4: 2003)

Dipping depth into solder tank: 2mm (JIS Z 3198-4: 2003)

Dipping time into solder tank: 10sec (JIS Z 3198-4: 2003)

Solder bath temperature: 245°C (JIS C 60068-2-69: 2019 Appendix B) The shorter the average value of the zero crossing time (sec), the higher the wetting speed, the better the solder wettability.

(2) Judgment criteria

A: The average value of the zero-crossing time (sec) is 6 seconds or less.

B: The average value of the zero crossing time (sec) exceeds 6 seconds.

The evaluation results are shown in Table 45 to Table 56.

In the table, aliphatic polyamide is used as polyamide, hexamethylene bishydroxystearylamine is used as bisamide, and p-toluamide is used as monoamide.

[Table 45]

[Table 46]

[Table 47]

[Table 48]

[Table 49]

[Table 50]

[Table 51]

[Table 52]

[Table 53]

[Table 54]

[Table 55]

[Table 56]

In the case of using the fluxes of the blending examples (F4-1) to (F4-57) with respect to the solder powder having the alloy composition shown in Test Example 1, the flux of the blending example (F4-58) is used. Compared with the case, it can be confirmed that the wetting speed of the solder is higher, and the solder wettability is high. Among them, it contains test example 1 The solder powder of the alloy composition and the solder paste of each flux of the blending examples (F4-1) to (F4-57) are the solder pastes of the implementation type containing the flux (F4).

Next, for the solder powders having the respective alloy compositions shown in Test Examples 2 to 258 and Test Examples 301 to 354, each of the fluxes of Blending Examples (F4-1) to (F4-58) was used, and the above-mentioned < Evaluation of the change of viscosity in solder paste over time>, <Evaluation of △T> and <Evaluation of wettability>, and <Evaluation of solder wettability (wetting speed)>.

From the results of this evaluation, it can be confirmed that in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 2 to 258, the viscosity increase suppression effect, the narrowing of ΔT, and the excellent wettability are shown. Among them, the solder paste containing each solder powder having the alloy composition of Test Examples 2 to 258 and the fluxes of the blending examples (F4-1) to (F4-57) is an implementation containing flux (F4) Type of solder paste.

On the other hand, in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 301 to 354, at least one of the viscosity increasing suppression effect, the narrowing of ΔT, and the excellent wettability is poor. result.

In addition, in the case of using the fluxes of the blending examples (F4-1) to (F4-57) with respect to the solder powders of test examples 2 to 258, and using the flux of blending example (F4-58) In comparison, it can be confirmed that the wetting speed of the solder is higher, and the solder wettability is better.

[Evaluation of solder paste containing flux (F5)]

Next, for the solder powder having the alloy composition shown in Test Example 1 using the fluxes of the blending examples (F5-1) to (F5-62) shown in Table 57 to Table 68, the above-mentioned <Solder Paste "Evaluation of the change in viscosity over time". In addition, the above-mentioned <Evaluation of ΔT> was performed by measuring the liquidus temperature and the solidus temperature of the solder powder. In addition, the above-mentioned "Evaluation of wettability" was performed using the solder paste just produced.

From these results, it can be confirmed that the solder pastes in the case of using the fluxes of the blending examples (F5-1) to (F5-62) with respect to the solder powder having the alloy composition shown in Test Example 1 all show It has the effect of suppressing viscosity increase, narrowing of △T and excellent wettability.

Next, for the solder powder with the alloy composition shown in Test Example 1 using the fluxes of the blending examples (F5-1) to (F5-62) shown in Table 57 to Table 68, the copper plate corrosion inhibition ability was performed evaluation of.

〈Evaluation of corrosion inhibition ability of copper plate〉

(1) Verification method

The evaluation of the corrosion inhibition ability of the copper plate is based on JIS Z 3197:2012 8.4.1 and is carried out by the following copper plate corrosion test.

Fabrication of the test copper plate: In the center of a phosphorous deoxidized copper plate with a size of 50mm×50mm×0.5mm, a steel ball with a diameter of 20mm is used to form a 3mm deep depression to form a test piece. After the test piece was degreased with acetone, it was immersed in sulfuric acid at 65°C for 1 minute to remove the oxide film on the surface. Then, after immersing in an ammonium persulfate solution at 20°C for 1 minute, it was washed with purified water and dried to form a test copper plate.

The method specified in JIS Z 3197:2012 8.1.3 was used to determine the solid content of the flux in each example, and an appropriate amount of flux containing 0.035 to 0.040g based on the solid content was added to the depression in the center of the test copper plate.

Next, the test copper plate was put into a constant temperature and humidity bath set at a humidification condition of a temperature of 40° C. and a relative humidity of 90%, and placed in the bath for 72 hours. For each flux of each example, two test copper plates were set, and one blank copper plate was added.

After being placed in the tank for 96 hours, it was taken out from the constant temperature and humidity tank, and the corrosion traces were compared with the blank copper plate by a microscope at 30 times. Evaluate the corrosion inhibition ability of copper plates based on the criteria shown below.

(2) Judgment criteria

A: No discoloration

B: Discoloration

The evaluation results are shown in Table 57 to Table 68.

In the table, aliphatic polyamide is used as polyamide, hexamethylene bishydroxystearylamine is used as bisamide, and p-toluamide is used as monoamide.

[Table 57]

[Table 58]

[Table 59]

[Table 60]

[Table 61]

[Table 62]

[Table 63]

[Table 64]

[Table 65]

[Table 66]

[Table 67]

[Table 68]

In the case of using the fluxes of the blending examples (F5-1) to (F5-61) with respect to the solder powder having the alloy composition shown in Test Example 1, the flux of the blending example (F5-62) is used Compared with the case, it can be confirmed that the corrosion inhibitory properties of the copper plates are improved. Among them, the solder paste containing the solder powder with the alloy composition of Test Example 1 and the fluxes of the blending examples (F5-1) to (F5-61) is the solder paste of the implementation type containing the flux (F5) .

Next, for the solder powders having the alloy compositions shown in Test Examples 2 to 258 and Test Examples 301 to 354, respectively, the fluxes of the blending examples (F5-1) to (F5-62) are used, and the above-mentioned < Evaluation of the change of viscosity in solder paste over time", "Evaluation of △T", "Evaluation of wettability", and "Evaluation of corrosion inhibition ability of copper plate".

From the results of this evaluation, it can be confirmed that in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 2 to 258, the viscosity increase suppression effect, the narrowing of ΔT, and the excellent wettability are shown. Among them, the solder paste containing each solder powder with the alloy composition of Test Examples 2 to 258 and the fluxes of the blending examples (F5-1) to (F5-61) is an implementation that contains flux (F5) Type of solder paste.

On the other hand, in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 301 to 354, at least one of the viscosity increasing suppression effect, the narrowing of ΔT, and the excellent wettability is poor. result.

In addition, in the case of using the fluxes of the blending examples (F5-1) to (F5-61) with respect to the solder powders of test examples 2 to 258, and using the flux of blending example (F5-62) In comparison, it can be confirmed that the corrosion inhibitory properties of the copper plates are improved.

[Evaluation of solder paste containing flux (F6)]

Next, for the solder powder with the alloy composition shown in Test Example 1 using the fluxes of the blending examples (F6-1) to (F6-60) shown in Table 69 to Table 77, the above-mentioned <Solder Paste "Evaluation of the change in viscosity over time". In addition, the above-mentioned <Evaluation of ΔT> was performed by measuring the liquidus temperature and the solidus temperature of the solder powder. In addition, the above-mentioned "Evaluation of wettability" was performed using the solder paste just produced.

From these results, it can be confirmed that the solder pastes in the case of using the fluxes of the blending examples (F6-1) to (F6-60) with respect to the solder powder having the alloy composition shown in Test Example 1 all show It has the effect of suppressing viscosity increase, narrowing of △T and excellent wettability.

Next, for the solder powder with the alloy composition shown in Test Example 1 using the fluxes of the blending examples (F6-1) to (F6-60) shown in Table 69 to Table 77, the solder is wetted Evaluation of speed (solder wettability).

<Assessment of solder wetting speed (solder wettability)>

(1) Verification method

The evaluation test of the solder wetting speed (solder wettability) is carried out in the following manner.

According to the arc surface solder test method, the copper plate of width 5mm × length 25mm × thickness 0.5mm was oxidized at 150°C for 1 hour to obtain the copper oxide plate of the test board. Solder Checker SAT-5200 (manufactured by RHESCA) was used. As a test device, a solder powder composed of the alloy composition shown in Test Example 1 was used as the solder, and the evaluation was performed in the following manner.

First, with respect to the flux measured in each example in the beaker, the test board was immersed for 5 mm to apply the flux to the test board. Next, after the flux was applied, the test board coated with the flux was quickly immersed in the solder tank of the alloy composition shown in Test Example 1, and the zero crossing time (sec) was obtained.

Next, the flux of each example was measured 5 times, and the average value of the obtained 5 zero-crossing times (sec) was calculated. The test conditions are set as follows.

Dipping speed into solder tank: 5mm/sec (JIS Z 3198-4: 2003)

Dipping depth into solder tank: 2mm (JIS Z 3198-4: 2003)

Dipping time into solder tank: 10sec (JIS Z 3198-4: 2003)

Solder bath temperature: 245°C (JIS C 60068-2-69: 2019 Appendix B) The shorter the average value of the zero crossing time (sec), the higher the wetting speed, the better the solder wettability.

(2) Judgment criteria

A: The average value of the zero-crossing time (sec) is 6 seconds or less.

B: The average value of the zero crossing time (sec) exceeds 6 seconds.

The evaluation results are shown in Table 69 to Table 77.

In the table, aliphatic polyamide is used as polyamide, hexamethylene bishydroxystearylamine is used as bisamide, and p-toluamide is used as monoamide.

[Table 69]

[Table 70]

[Table 71]

[Table 72]

[Table 73]

[Table 74]

[Table 75]

[Table 76]

[Table 77]

In the case of using the fluxes of the blending examples (F6-1) to (F6-59) with respect to the solder powder having the alloy composition shown in Test Example 1, the flux of the blending example (F6-60) is used. Compared with the case, it can be confirmed that the solder wetting speed is higher, and the solder wettability is better. Among them, the solder paste containing the solder powder with the alloy composition of Test Example 1 and the fluxes of the blending examples (F6-1) to (F6-59) is the solder paste of the implementation type containing the flux (F6) .

Next, for the solder powders having the alloy compositions shown in Test Examples 2 to 258 and Test Examples 301 to 354, each of the fluxes of the blending examples (F6-1) to (F6-60) was used, and the above-mentioned < Evaluation of the change of viscosity in solder paste over time>, <Evaluation of △T> and <Evaluation of wettability>, and <Evaluation of solder wetting speed (solder wettability)>.

From the results of this evaluation, it can be confirmed that in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 2 to 258, the viscosity increase suppression effect, the narrowing of ΔT, and the excellent wettability are shown. Among them, the solder paste containing each solder powder with the alloy composition of Test Examples 2 to 258 and the fluxes of the blending examples (F6-1) to (F6-59) is an implementation that contains flux (F6) Type of solder paste.

On the other hand, in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 301 to 354, at least one of the viscosity increasing suppression effect, the narrowing of ΔT, and the excellent wettability is poor. result.

In addition, in the case of using the fluxes of the blending examples (F6-1) to (F6-59) with respect to the solder powders of test examples 2 to 258, and using the flux of blending example (F6-60) In comparison, it can be confirmed that the wetting speed of the solder is higher, and the solder wettability is better.

[Evaluation of solder paste containing flux (F7)]

Next, for the solder powder having the alloy composition shown in Test Example 1 using the fluxes of the blending examples (F7-1) to (F7-54) shown in Table 78 to Table 85, the above-mentioned <Solder Paste Viscosity in anytime "Assessment of Changes in Time." In addition, the above-mentioned <Evaluation of ΔT> was performed by measuring the liquidus temperature and the solidus temperature of the solder powder. In addition, the above-mentioned "Evaluation of wettability" was performed using the solder paste just produced.

From these results, it can be confirmed that the solder pastes in the case of using the fluxes of the blending examples (F7-1) to (F7-54) with respect to the solder powder having the alloy composition shown in Test Example 1 all show It has the effect of suppressing viscosity increase, narrowing of △T and excellent wettability.

Next, for the solder powder with the alloy composition shown in Test Example 1, the fluxes of the blending examples (F7-1) to (F7-54) shown in Table 78 to Table 85 were used, and the flux was shaken. Evaluation of viscosity reduction, printing sag suppression ability of solder paste, and heating sag suppression ability of solder paste.

<Assessment of Flux Shake Viscosity Reduction>

(1) Verification method

The evaluation of thixotropic viscosity reduction is carried out in accordance with JIS Z3284-3:2014 4.2 and using a spiral viscometer. Set the rotation speed of the viscometer to 3rpm and 30rpm, read the viscosity after a predetermined time of rotation and calculate the viscosity reduction ratio.

(2) Judgment criteria

A: Shake viscosity reduction ratio is 0.30 or more

B: Shake viscosity reduction ratio is less than 0.30

〈Evaluation of printing sagging suppression ability of solder paste〉

(1) Verification method

The evaluation of the printing sagging suppression ability of solder paste (flux: solder powder = 11:89 mass ratio) is based on JIS Z3284-2014 4.3, using a stainless steel metal mask with a solder paste printed part formed in a predetermined pattern Solder paste is printed on the copper plate, after removing the metal mask, at room temperature 25±5℃, relative humidity Store at 50±10% for 10 to 20 minutes. In each printed pattern, visually confirm the minimum interval between all printed solder pastes that are not integrated. The thickness of the metal mask is 0.2mm, and the solder paste printing part is a quadrangular opening and the size is 3.0×1.5mm. In the solder paste printing part, a plurality of openings of the same size are arranged at different intervals, and the interval L of the openings is 0.2-0.3-0.4-0.5-0.6-0.7-0.8-0.9-1.0-1.1-1.2mm.

(2) Judgment criteria

A: After printing, the minimum distance that is not integrated is 0.2mm or less

B: After printing, the minimum distance that is not integrated is more than 0.2mm

<Evaluation of the ability to suppress heat sag of solder paste>

(1) Verification method

The heat sag suppression capability of solder paste (flux: solder powder = 11:89 mass ratio) is evaluated in accordance with JIS Z3284-2014 4.4, using a stainless steel metal mask with a solder paste printed part formed in a predetermined pattern The solder paste is printed on the copper plate. After removing the metal mask, heat at 150±10°C for 10 minutes. In the printed patterns, visually confirm that the printed solder paste is not integrated with the minimum interval. The thickness of the metal mask is 0.2mm, and the solder paste printing part is a quadrangular opening and the size is 3.0×1.5mm. In the solder paste printing part, a plurality of openings of the same size are arranged at different intervals, and the interval L of the openings is 0.2-0.3-0.4-0.5-0.6-0.7-0.8-0.9-1.0-1.1-1.2mm.

(2) Judgment criteria

A: The minimum distance of not being integrated is 1.0mm or less

B: The minimum distance that is not integrated exceeds 1.0mm

<Comprehensive Evaluation>

A: In Table 78 to Table 85, all the evaluations of flux reduction and viscosity reduction, printing sag suppression ability of solder paste, and heating sag suppression ability of solder paste are all A.

B: In Table 78 to Table 85, at least one of the evaluations of flux sag reduction, printing sag suppression ability of solder paste, and heating sag suppression ability of solder paste is B.

The evaluation results are shown in Table 78 to Table 85.

In the table, an aliphatic polyamide is used as the polyamide.

In the table, a mixture (molecular weight 300 to 1500) of compounds represented by the following chemical formula (3) is used as the cyclic amide oligomer. In this chemical formula (3), m1, m2, m3, and m4 are the repeating numbers of _{methylene (CH 2 ).} p represents the repeating number of the unit.

[Table 78]

[Table 79]

[Table 80]

[Table 81]

[Table 82]

[Table 83]

[Table 84]

[Table 85]

In the case of using the fluxes of the blending examples (F7-1) to (F7-52) with respect to the solder powder having the alloy composition shown in Test Example 1, the flux of the blending example (F7-53) is used. Compared with the situation, it can be confirmed that the thixotropic viscosity reduction of the flux is improved, and the printing sag caused by the flow of the solder paste after printing is suppressed, and the heating sag of the solder paste caused by the heating during soldering is suppressed.

In addition, in the case of using the fluxes of the blending examples (F7-1) to (F7-52) with respect to the solder powder having the alloy composition shown in Test Example 1, it is combined with the use of the blending example (F7-54). Compared with the case of the flux, it can be confirmed that all the solder pastes are suppressed due to the heating during soldering.

Among them, the solder paste containing the solder powder with the alloy composition of Test Example 1 and the fluxes of the blending examples (F7-1) to (F7-52) is one of the implementation types containing the flux (F7) Solder paste.

Next, for the solder powders having the alloy compositions shown in Test Examples 2 to 258 and Test Examples 301 to 354, each of the fluxes of Blending Examples (F7-1) to (F7-54) was used, and the above-mentioned < Evaluation of the change of viscosity in solder paste over time>, <Evaluation of △T> and <Evaluation of wettability>, as well as <Evaluation of flux reduction viscosity>, <Printing sagging of solder paste Evaluation of Inhibition Ability> and "Evaluation of Inhibition Ability to Heat Sag of Solder Paste".

From the results of this evaluation, it can be confirmed that in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 2 to 258, the viscosity increase suppression effect, the narrowing of ΔT, and the excellent wettability are shown. Among them, the solder paste containing each solder powder having the alloy composition of Test Examples 2 to 258 and the fluxes of the blending examples (F7-1) to (F7-52) is an implementation that contains flux (F7) Type of solder paste.

On the other hand, in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 301 to 354, at least one of the viscosity increasing suppression effect, the narrowing of ΔT, and the excellent wettability is poor. result.

In addition, in the case of using the fluxes of the blending examples (F7-1) to (F7-52) with respect to the solder powders of test examples 2 to 258, and using the flux of blending example (F7-53) In comparison, it can be confirmed that the thixotropic viscosity reduction of the flux is improved, and the printing sag caused by the flow of the solder paste after printing is suppressed, and the heating sag of the solder paste caused by the heating during soldering is suppressed.

In addition, in the case of using the fluxes of the blending examples (F7-1) to (F7-52) with respect to the solder powders of test examples 2 to 258, and using the flux of blending example (F7-54) In comparison, it can be confirmed that the heating sagging of the solder paste caused by the heating during soldering is suppressed.

[Evaluation of solder paste containing flux (F8)]

Next, for the solder powder having the alloy composition shown in Test Example 1 using the fluxes of the blending examples (F8-1) to (F8-54) shown in Table 86 to Table 94, the above-mentioned <Solder Paste "Evaluation of the change in viscosity over time". In addition, the above-mentioned <Evaluation of ΔT> was performed by measuring the liquidus temperature and the solidus temperature of the solder powder. In addition, the above-mentioned "Evaluation of wettability" was performed using the solder paste just produced.

From these results, it can be confirmed that the solder pastes in the case of using the fluxes of the blending examples (F8-1) to (F8-54) with respect to the solder powder having the alloy composition shown in Test Example 1 all show It has the effect of suppressing viscosity increase, narrowing of △T and excellent wettability.

Next, for the solder powder with the alloy composition shown in Test Example 1 using the fluxes of the blending examples (F8-1) to (F8-54) shown in Table 86 to Table 94, the thixotropic viscosity reduction was performed. Sexual assessment.

In addition, for the solder powder composed of the alloy composition shown in Test Example 1 using the fluxes of the blending examples (F8-8) to (F8-54) shown in Table 87 to Table 94, further assistance is provided. Evaluation of precipitation and agglomeration of crystals in flux and solder paste.

<Assessment of Shake Viscosity Reduction>

(1) Verification method

The evaluation of the shake viscosity reduction was performed using a double cylindrical tube type rotary viscometer Malcom Viscometer PCU-205 (manufactured by Malcom).

Using the aforementioned double cylindrical tube type rotary viscometer, the viscosity of each solder paste was measured in sequence with the number of revolutions (rpm) and measurement time (min) shown below under the condition of 25°C.

Change the rotational speed of the viscometer in sequence to: 3 minutes at 10rpm, 6 minutes at 3rpm, 3 minutes at 4rpm, 3 minutes at 5rpm, 3 minutes at 10rpm, 2 minutes at 20rpm, 2 minutes at 30rpm Minutes, 1 minute at 10 rpm.

Then, according to the following formula, calculate the viscosity reduction ratio from the viscosity at 3 revolutions (3 rpm) and 30 revolutions (30 rpm).

Shake viscosity reduction ratio = Log (viscosity at 3 revolutions / viscosity at 30 revolutions)

Then follow the following criteria for evaluation.

(2) Judgment criteria

A: Shake viscosity reduction ratio is 0.40 or more

B: Shake viscosity reduction ratio is less than 0.40

<Precipitation of crystals and formation of agglomeration>

(1) Verification method

The following methods are used for the precipitation and crystallization of the fluxes of the examples shown in Table 87 to Table 94 and the solder pastes (flux: solder powder = 11:89 mass ratio). Evaluation of block generation. Then follow the following criteria for evaluation. For the fluxes of the examples shown in Table 86 and the solder pastes using them, the evaluation of the precipitation of crystals and the occurrence of agglomeration was not performed.

Evaluation of flux:

100 mL of each flux was collected, put in a 200 mL glass beaker, and stirred with a reagent spoon 10 times to prepare a sample for visual observation. The same operation was performed to prepare three samples for visual observation of each flux.

The appearance of each sample after stirring 10 times was visually observed, and the state of the precipitation of crystals and the occurrence of agglomeration was evaluated.

Evaluation of solder paste:

Each solder paste was measured 3 times using a fineness meter GS-2256M (manufactured by Taiyou Machinery Co., Ltd., measurement range: 0 to 100 μm). Then, the average value of the three measurements is calculated and the average value is used as the size (particle size) of the aggregate contained in the solder paste.

The surface of the micrometer is provided with grooves whose depth increases from 0 at one end to the maximum value at the other end by a certain value. When the sample of solder paste is flattened from the maximum depth side by a squeegee, it will condense accordingly. Line marks or grain marks remain at the depth of the size of the object. By the depth of the position where the linear or granular traces are formed, the precipitation of crystals and the occurrence of agglomeration in the sample of the solder paste can be evaluated.

(2) Judgment criteria

A: Crystals and agglomerates were not visually confirmed in the flux, and crystals and droplets were not visually confirmed in the solder paste.

B: Crystals and agglomerations are not visually confirmed in the flux, and crystals or agglomerations of 50 μm or more are not visually confirmed in the solder paste, but crystals or agglomerations of less than 50 μm are present.

C: Crystals and agglomerations are visually confirmed in any one of the three samples of the flux, or the presence of crystals or agglomerations of 50 μm or more in the solder paste.

<Comprehensive Evaluation>

A: In Table 87 to Table 94, the evaluation of the thixotropic viscosity reduction is A and the evaluation of the precipitation of crystals and the generation of agglomeration is A.

B: In Table 87 to Table 94, the evaluation of the thixotropic viscosity reduction is A and the evaluation of the precipitation of crystals and the generation of agglomeration is B.

C: In Table 87 to Table 94, at least the evaluation of the shake viscosity reduction is B.

The evaluation results are shown in Table 86 to Table 94.

[Table 86]

[Table 87]

[Table 88]

[Table 89]

[Table 90]

[Table 91]

[Table 92]

[Table 93]

[Table 94]

In the case of using the fluxes of the blending examples (F8-1) to (F8-52) with respect to the solder powder having the alloy composition shown in Test Example 1, the blending examples (F8-53) and blending examples ( F8-54) help Compared with the case of the flux, it can be confirmed that the thixotropic viscosity reduction of the solder paste is improved, that is, the fluidity and shape retention of the solder paste are good.

In addition, when the fluxes of the blending examples (F8-8) to (F8-54) are used with respect to the solder powder having the alloy composition shown in Test Example 1, it can be confirmed that both the flux and the solder paste are suppressed The precipitation and agglomeration of crystals.

Among these, the solder powder containing the alloy composition of Test Example 1 and the solder paste containing the fluxes of the blending examples (F8-1) to (F8-52) and (F8-54) are those containing flux (F8 ) Solder paste of implementation type.

Next, for the solder powders having the alloy compositions shown in Test Examples 2 to 258 and Test Examples 301 to 354, each of the fluxes of Blending Examples (F8-1) to (F8-54) was used, and the above-mentioned < Evaluation of Viscosity Changes in Solder Paste with Time, "Evaluation of △T" and "Evaluation of Wettability", and "Evaluation of Thixotropic Viscosity Reduction" and "Precipitation of Crystals and Generation of Agglomeration" .

From the results of this evaluation, it can be confirmed that in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 2 to 258, the viscosity increase suppression effect, the narrowing of ΔT, and the excellent wettability are shown. Among them, the solder paste containing each solder powder having the alloy composition of Test Examples 2 to 258, and the fluxes of Blending Examples (F8-1) to (F8-52), (F8-54), is a solder paste containing an auxiliary Solder paste of the implementation type of flux (F8).

On the other hand, in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 301 to 354, at least one of the viscosity increasing suppression effect, the narrowing of ΔT, and the excellent wettability is poor. result.

In addition, in the case of using the fluxes of the blending examples (F8-1) to (F8-52) with respect to the solder powders of test examples 2 to 258, it is the same as using blending example (F8-53) and blending example (F8). -54) flux Compared with the situation, it can be confirmed that the tremor and viscosity reduction properties of the solder paste are improved, that is, the fluidity and shape retention of the solder paste are good.

In addition, when the fluxes of the blending examples (F8-8) to (F8-54) were used with respect to the solder powder of Test Example 1, it was confirmed that both the flux and the precipitation of crystals in the solder paste were suppressed. The occurrence of lumps.

[Evaluation of solder paste containing flux (F9)]

Next, for the solder powder with the alloy composition shown in Test Example 1 using the fluxes of the blending examples (F9-1) to (F9-76) shown in Table 95 to Table 109, the above-mentioned <Solder Paste "Evaluation of the change in viscosity over time". In addition, the above-mentioned <Evaluation of ΔT> was performed by measuring the liquidus temperature and the solidus temperature of the solder powder. In addition, the above-mentioned "Evaluation of wettability" was performed using the solder paste just produced.

From these results, it can be confirmed that the solder pastes in the case of using the fluxes of the blending examples (F9-1) to (F9-76) with respect to the solder powder having the alloy composition shown in Test Example 1 all show It has the effect of suppressing viscosity increase, narrowing of △T and excellent wettability.

Next, for the solder powder having the alloy composition shown in Test Example 1, the solder paste (assisted) when the fluxes of the blending examples (F9-1) to (F9-76) shown in Table 95 to Table 109 are used Flux: Solder powder = 11:89 mass ratio), the void generation and solder wetting speed (solder wettability) are evaluated.

<Assessment of void generation>

(1) Void generation rate

Using a metal mask, the solder paste was printed 120μm high on the 8mm×8mm Cu-OSP electrode (N=15). Then reflow in the atmosphere. The reflow profile is set to hold at 190°C for 2 minutes, and then heat up to 260°C at 1.5°C/sec.

Microfocus X-ray System XVR-160 manufactured by UNi-HiTESYSTEM was used to observe the penetration image of the soldered part (solder bump) after reflow, and determine the void generation rate.

Specifically, through observation of the solder bump from the top to the bottom, a circular solder bump penetration image is obtained, and the metal filling part and the void part are identified based on the contrast of the color tone, and the void is obtained by automatic analysis The area ratio is used as the void generation rate. The void generation rate thus obtained was used to evaluate the ease of void generation based on the following criteria.

A: In all the 15 welded parts, the void generation rate is 15% or less

B: Among the 15 welded parts, although the void generation rate exceeds 15%, all of them are below 20%

C: Among the 15 welded parts, there are cases where the void generation rate exceeds 20%

<Assessment of solder wetting speed (solder wettability)>

According to JIS Z 3198-4:2003, the solder wettability of the flux is evaluated.

Specifically, apply the flux of each blending example to the lower end of the surface of a copper plate with a width of 5 mm × a length of 25 mm × a thickness of 0.5 mm and 3 mm in the lengthwise direction that has been calcined at 150°C for 1 hour. Under the conditions, immerse in the solder bath and measure the zero crossing time.

<Dipping conditions>

Dipping speed into solder tank: 5mm/sec (JIS Z 3198-4: 2003)

Dipping depth into solder tank: 2mm (JIS Z 3198-4: 2003)

Dipping time into solder tank: 10sec (JIS Z 3198-4: 2003)

Solder tank temperature: 250°C (JIS C 60068-2-69: 2019 Appendix B)

The solder wettability is evaluated based on the following criteria.

A: The zero-crossing time is 5.5 seconds or less

B: The zero-crossing time exceeds 5.5 seconds

<Comprehensive Evaluation>

A: The evaluation of void generation is A or B, and the evaluation of solder wetting speed (solder wettability) is A

B: The evaluation of void generation is C, or the evaluation of solder wetting speed (solder wettability) is at least one of B

The evaluation results are shown in Table 95 to Table 109.

In the table, aliphatic polyamide is used as polyamide, hexamethylene bishydroxystearylamine is used as bisamide, and p-toluamide is used as monoamide.

[Table 95]

[Table 96]

[Table 97]

[Table 98]

[Table 99]

[Table 100]

[Table 101]

[Table 102]

[Table 103]

[Table 104]

[Table 105]

[Table 106]

[Table 107]

[Table 108]

[Table 109]

In the case of using the fluxes of the blending examples (F9-1) to (F9-74) with respect to the solder powder having the alloy composition shown in Test Example 1, it is different from the flux of the blending example (F9-75) Compared with the case, it can be confirmed that the solder wettability is better.

In addition, in the case of using the fluxes of the blending examples (F9-1) to (F9-74) with respect to the solder powder having the alloy composition shown in Test Example 1, it is combined with the use of the blending example (F9-76). Compared with the case of flux, it can be confirmed that the generation of voids is suppressed.

Among them, the solder paste containing the solder powder with the alloy composition of Test Example 1 and the fluxes of the blending examples (F9-1) to (F9-74) is one of the implementation types containing the flux (F9) Solder paste.

Next, for the solder powders having the respective alloy compositions shown in Test Examples 2 to 258 and Test Examples 301 to 354, the fluxes of the blending examples (F9-1) to (F9-76) were used, and the above-mentioned < Evaluation of the change of viscosity in solder paste over time>, <Evaluation of △T> and <Evaluation of wettability>, and <Evaluation of void generation> and <Solder wetting speed (solder wettability) Evaluation>.

From the results of this evaluation, it can be confirmed that in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 2 to 258, the viscosity increase suppression effect, the narrowing of ΔT, and the excellent wettability are shown. Among them, the solder paste containing each solder powder having the alloy composition of Test Examples 2 to 258 and the fluxes of the blending examples (F9-1) to (F9-74) is an implementation that contains flux (F9) Type of solder paste.

On the other hand, in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 301 to 354, at least one of the viscosity increasing suppression effect, the narrowing of ΔT, and the excellent wettability is poor. result.

In addition, in the case of using the fluxes of the blending examples (F9-1) to (F9-74) with respect to the solder powders of test examples 2 to 258, and using the flux of blending example (F9-75) In comparison, it can be confirmed that the solder wettability is better.

In addition, in the case of using the fluxes of the blending examples (F9-1) to (F9-74) with respect to the solder powders of test examples 2 to 258, and using the flux of blending example (F9-76) In comparison, it can be confirmed that the generation of voids is suppressed.

[Evaluation of solder paste containing flux (F10)]

Next, for the solder powder having the alloy composition shown in Test Example 1 using the fluxes of the blending examples (F10-1) to (F10-30) shown in Table 110 to Table 115, the above-mentioned <Solder Paste "Evaluation of the change in viscosity over time". In addition, the above-mentioned <Evaluation of ΔT> was performed by measuring the liquidus temperature and the solidus temperature of the solder powder. In addition, the above-mentioned "Evaluation of wettability" was performed using the solder paste just produced.

From these results, it can be confirmed that the solder pastes in the case of using the fluxes of the blending examples (F10-1) to (F10-30) with respect to the solder powder having the alloy composition shown in Test Example 1 all show It has the effect of suppressing viscosity increase, narrowing of △T and excellent wettability.

Next, for the solder powder having the alloy composition shown in Test Example 1, the solder paste (assisted) when the fluxes of the blending examples (F10-1) to (F10-30) shown in Table 110 to Table 115 are used Flux: Solder powder = 11:89 mass ratio), the dryness, void generation, and solder wetting speed (solder wettability) are evaluated.

<Assessment of dryness>

According to JIS Z 3197: 2012, 8.5.1 dryness test to evaluate the dryness of the flux.

：21μm)之焊料膏。 Specifically, a mixture of each flux of the formulation examples (F10-1) to (F10-30) and the alloy composition shown in Test Example 1 was produced at a mass ratio of flux: solder powder = 11:89. Solder powder (average particle size

: 21μm) solder paste.

Then follow the above-mentioned JIS test method to make a test piece and test it, and evaluate the dryness of the flux (the ease of drying of the flux, specifically by the adhesion degree of the powder talc on the surface of the flux residue sprayed on the test piece). In terms of the adhesiveness of flux residue).

The evaluation is based on the case where powder talc can be removed by brushing as A, and the case where it cannot be removed as B.

<Assessment of void generation>

Using a metal mask, the solder paste made in the same way as in the dryness test was printed on an 8mm×8mm Cu-OSP electrode (N=15) with a height of 120μm. Then reflow in the atmosphere. The reflow temperature profile is set to hold at 190°C for 2 minutes, and then heat up to 260°C at 1.5°C/sec.

Microfocus X-ray System XVR-160 manufactured by UNi-HiTESYSTEM was used to observe the penetration image of the soldered part (solder bump) after reflow, and determine the void generation rate.

Specifically, through observation of the solder bump from the top to the bottom, a circular solder bump penetration image is obtained, and the metal filling part and the void part are identified based on the contrast of the color tone, and the void is obtained by automatic analysis The area ratio is used as the void generation rate. The void generation rate thus obtained was used to evaluate the ease of void generation based on the following criteria.

A: In all the 15 welded parts, the void generation rate is 15% or less

B: Among the 15 welded parts, although the void generation rate exceeds 15%, all of them are below 20%

C: Among the 15 welded parts, there are cases where the void generation rate exceeds 20%

<Assessment of solder wetting speed (solder wettability)>

According to JIS Z 3198-4:2003, the solder wettability of the flux is evaluated.

Specifically, apply the flux of each blending example to the lower end of the surface of a copper plate with a width of 5 mm × a length of 25 mm × a thickness of 0.5 mm and 3 mm in the lengthwise direction that has been calcined at 150°C for 1 hour. Under the conditions, immerse in the solder bath and measure the zero crossing time.

<Dipping conditions>

Dipping speed into solder tank: 5mm/sec (JIS Z 3198-4: 2003)

Dipping depth into solder tank: 2mm (JIS Z 3198-4: 2003)

Dipping time into solder tank: 10sec (JIS Z 3198-4: 2003)

Solder tank temperature: 250°C (JIS C 60068-2-69: 2019 Appendix B)

The solder wettability is evaluated based on the following criteria.

A: The zero-crossing time is 5.5 seconds or less

B: The zero-crossing time exceeds 5.5 seconds

<Comprehensive Evaluation>

A: The evaluation of void generation is A or B, and the evaluation of dryness and solder wetting speed (solder wettability) is A

B: The evaluation of void generation is C, or the evaluation of dryness or solder wetting speed (solder wettability) is at least one of B

The evaluation results are shown in Table 110 to Table 115.

In the table, hexamethylene bishydroxystearylamine is used as bisamide.

[Table 110]

[Table 111]

[Table 112]

[Table 113]

[Table 114]

[Table 115]

In the case of using the fluxes of the blending examples (F10-1) to (F10-28) with respect to the solder powder having the alloy composition shown in Test Example 1, the flux of the blending example (F10-29) is used. Compared with the case, it can be confirmed that all have good drying properties and solder wettability is better.

In addition, in the case of using the fluxes of the blending examples (F10-1) to (F10-28) with respect to the solder powder having the alloy composition shown in Test Example 1, it is compatible with the use of the blending example (F10-30). Compared with the case of flux, it can be confirmed that the generation of voids is more suppressed. Among them, the solder containing the alloy composition of Test Example 1 The powder, and the solder paste of each flux of the formulation examples (F10-1) to (F10-28) are the solder pastes of the implementation type containing the flux (F10).

Next, for the solder powders having the alloy compositions shown in Test Examples 2 to 258 and Test Examples 301 to 354, respectively, the fluxes of the blending examples (F10-1) to (F10-30) are used, and the above-mentioned < Evaluation of the change of viscosity in solder paste over time>, <Evaluation of △T> and <Evaluation of wettability>, as well as <Evaluation of dryness>, <Evaluation of void generation> and <Wetting rate of solder (Evaluation of solder wettability)>.

From the results of this evaluation, it can be confirmed that in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 2 to 258, the viscosity increase suppression effect, the narrowing of ΔT, and the excellent wettability are shown. Among them, the solder paste containing each solder powder with the alloy composition of Test Examples 2 to 258 and the fluxes of the blending examples (F10-1) to (F10-28) is an implementation that contains flux (F10) Type of solder paste.

On the other hand, in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 301 to 354, at least one of the viscosity increasing suppression effect, the narrowing of ΔT, and the excellent wettability is poor. result.

In addition, in the case of using the fluxes of the blending examples (F10-1) to (F10-28) with respect to the solder powders of test examples 2 to 258, and using the flux of blending example (F10-29) In comparison, it can be confirmed that all have good drying properties and solder wettability is better.

In addition, in the case of using the fluxes of the blending examples (F10-1) to (F10-28) with respect to the solder powders of test examples 2 to 258, and using the flux of blending example (F10-30) In comparison, it can be confirmed that the generation of voids is more suppressed.

[Evaluation of solder paste containing flux (F11)]

Next, for the solder powder having the alloy composition shown in Test Example 1 using the fluxes of the blending examples (F11-1) to (F11-18) shown in Table 116 to Table 118, the above-mentioned <Solder Paste "Evaluation of the change in viscosity over time". In addition, the above-mentioned <Evaluation of ΔT> was performed by measuring the liquidus temperature and the solidus temperature of the solder powder. In addition, the above-mentioned "Evaluation of wettability" was performed using the solder paste just produced.

From these results, it can be confirmed that the solder pastes in the case of using the fluxes of the blending examples (F11-1) to (F11-18) with respect to the solder powder having the alloy composition shown in Test Example 1 all show It has the effect of suppressing viscosity increase, narrowing of △T and excellent wettability.

Next, for the solder powder with the alloy composition shown in Test Example 1, the solder paste (assisted) when the fluxes of the blending examples (F11-1) to (F11-18) shown in Table 116 to Table 118 are used Flux: Solder powder = 11:89 mass ratio), and the viscosity increase suppression evaluation and wettability evaluation are performed separately.

<Evaluation of Thickening Suppression>

According to the method described in JIS Z 3284-3:2014 "4.2 Viscosity Characteristic Test", using a rotary viscometer (PCU-205, manufactured by Malcom Co., Ltd.), at the speed of rotation: 10rpm, the measurement temperature: 25 ℃ The viscosity of the obtained solder paste was continuously measured for 12 hours. Then compare the initial viscosity (viscosity after 30 minutes of stirring) with the viscosity after 13 hours, and evaluate the viscosity increase inhibition effect based on the following criteria.

Viscosity after 13 hours≦Initial viscosity×1.2: The increase in viscosity over time is small, good (A)

Viscosity after 13 hours>Initial viscosity×1.2: The viscosity increases with time, which is not good (B)

<Assessment of wettability>

The same as the above "Evaluation of Tackification Suppression", a metal mask with an opening diameter of 6.5 mm, 4 openings, and a mask thickness of 0.2 mm was used to print each flux of the blending examples (F11-1) to (F11-18) On a Cu board, heated from 25°C to 260°C at a temperature increase rate of 1°C/sec _{in a N 2 gas atmosphere in a reflow furnace, and then air-cooled to room temperature (25°C) to form 4 solder bumps.} An optical microscope (magnification: 100 times) was used to observe the appearance of the obtained bumps, and evaluated according to the following criteria.

In all of the four solder bumps, solder particles that were not completely melted were not observed: solder wettability was good (A).

In one or more of the four solder bumps, solder particles that were not completely melted were observed: poor solder wettability (B).

The evaluation results are shown in Table 117 to Table 119.

In each table, the metal deactivators A to H shown below are used as hindered phenol-based metal deactivators.

‧「Metal Deactivator A」

Reagent name: Bis[3-(3-tertiarybutyl-4-hydroxy-5-methylphenyl)propionic acid][ethylene bis(oxyethylene)]; CAS No. 36443-68-2.

‧「Metal Deactivator B」

Reagent name: N,N'-hexamethylenebis[3-(3,5-di(tertiarybutyl)-4-hydroxyphenyl)propaneamide]; CAS No.23128-74-7.

‧「Metal Deactivator C」

Reagent name: 1,6-hexanediol bis[3-(3,5-di(tertiarybutyl)-4-hydroxyphenyl)propionate]; CAS No. 35074-77-2.

‧「Metal Deactivator D」

Reagent name: 2,2'-methylenebis[6-(1-methylcyclohexyl)-p-cresol]; CAS No. 77-62-3.

‧「Metal Deactivator E」

Reagent name: 2,2'-methylene bis(6-tertiary butyl-p-cresol); CAS No. 119-47-1.

‧「Metal Deactivator F」

Reagent name: 2,2'-methylenebis(6-tertiarybutyl-4-ethylphenol); CAS No. 88-24-4.

‧「Metal Deactivator G」

Reagent name: N-(2H-1,2,4-triazol-5-yl)salanamide; CAS No. 36411-52-6.

‧「Metal Deactivator H」

Reagent name: N,N'-bis[2-[2-(3,5-di(tertiary butyl)-4-hydroxyphenyl)ethylcarbonyloxy]ethyl] glufamide; CAS No .70331-94-1.

[Table 116]

[Table 117]

[Table 118]

In the case of using the fluxes of the blending examples (F11-1) to (F11-17) with respect to the solder powder with the alloy composition shown in Test Example 1, the flux of the blending example (F11-18) is used. Compared with the case, it can be confirmed that the effect of thickening suppression is improved.

Among them, the solder paste containing the solder powder with the alloy composition of Test Example 1 and the fluxes of the blending examples (F11-1) to (F11-17) is one of the implementation types containing the flux (F11) Solder paste.

Next, for the solder powders having the alloy compositions shown in Test Examples 2 to 258 and Test Examples 301 to 354, respectively, the fluxes of the blending examples (F11-1) to (F11-18) are used, and the above-mentioned < Evaluation of the change of viscosity in solder paste over time>, <Evaluation of △T> and <Evaluation of wettability>, as well as <Evaluation of viscosity increase inhibition> and <Evaluation of wettability>.

From the results of this evaluation, it can be confirmed that in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 2 to 258, the viscosity increase suppression effect, the narrowing of ΔT, and the excellent wettability are shown. Among them, the solder paste containing each solder powder with the alloy composition of Test Examples 2 to 258 and the fluxes of the blending examples (F11-1) to (F11-17) is an implementation that contains flux (F11) Type of solder paste.

On the other hand, in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 301 to 354, at least one of the viscosity increasing suppression effect, the narrowing of ΔT, and the excellent wettability is poor. result.

In addition, in the case of using the fluxes of the blending examples (F11-1) to (F11-17) with respect to the solder powders of test examples 2 to 258, and using the flux of blending example (F11-18) In comparison, it can be confirmed that the effects of thickening suppression are improved.

[Evaluation of solder paste containing flux (F12)]

Next, for the solder powder with the alloy composition shown in Test Example 1 using the fluxes of the blending examples (F12-1) to (F12-8) shown in Table 119, the above-mentioned "Viscosity in Solder Paste" "Assessment of changes over time." In addition, the above-mentioned <Evaluation of ΔT> was performed by measuring the liquidus temperature and the solidus temperature of the solder powder. In addition, the above-mentioned "Evaluation of wettability" was performed using the solder paste just produced.

From these results, it can be confirmed that the solder pastes in the case of using the fluxes of the blending examples (F12-1) to (F12-8) with respect to the solder powder having the alloy composition shown in Test Example 1 all show It has the effect of suppressing viscosity increase, narrowing of △T and excellent wettability.

Next, for the solder powder with the alloy composition shown in Test Example 1, the solder paste (flux: solder) in the case of using the fluxes of the blending examples (F12-1) to (F12-8) shown in Table 119 The mass ratio of powder = 11:89), and the evaluation of the viscosity increase inhibition and the evaluation of the wettability were performed respectively.

<Evaluation of Thickening Suppression>

According to the method described in JIS Z 3284-3:2014 "4.2 Viscosity Characteristic Test", using a rotary viscometer (PCU-205, manufactured by Malcom Co., Ltd.), at the speed of rotation: 10rpm, the measurement temperature: 25 ℃ The viscosity of the obtained solder paste was continuously measured for 12 hours. Then compare the initial viscosity (viscosity after 30 minutes of stirring) with the viscosity after 13 hours, and evaluate the viscosity increase inhibition effect based on the following criteria.

Viscosity after 13 hours≦Initial viscosity×1.2: The increase in viscosity over time is small, good (A)

Viscosity after 13 hours>Initial viscosity×1.2: The viscosity increases with time, which is not good (B)

<Assessment of wettability>

The same as the above "Tackification suppression evaluation", use a metal mask with an opening diameter of 6.5 mm, 4 openings, and a mask thickness of 0.2 mm, and print the fluxes of the blending examples (F12-1) to (F12-8) On a Cu board, heated from 25°C to 260°C at a temperature increase rate of 1°C/sec _{in a N 2 gas atmosphere in a reflow furnace, and then air-cooled to room temperature (25°C) to form 4 solder bumps.} An optical microscope (magnification: 100 times) was used to observe the appearance of the obtained bumps, and evaluated according to the following criteria.

In all of the four solder bumps, solder particles that were not completely melted were not observed: solder wettability was good (A).

In one or more of the four solder bumps, solder particles that were not completely melted were observed: poor solder wettability (B).

The evaluation results are shown in Table 119.

In each table, the following metal deactivators A to E are used as nitrogen-containing compound metal deactivators.

‧「Metal Deactivator A」

Reagent name: N-(2H-1,2,4-triazol-5-yl)salanamide; CAS No.36411-52-6

‧「Metal Deactivator B」

Reagent name: Dodecanedioic acid bis[N2-(2-hydroxybenzyl)hydrazine]; CAS No.63245-38-5

‧「Metal Deactivator C」

Reagent name: Melamine

‧「Metal Deactivator D」

Reagent name: Product name "ADK STAB ZS-27" manufactured by ADEKA

‧「Metal Deactivator E」

Reagent name: Product name "ADK STAB ZS-90" manufactured by ADEKA

In each table, the metal deactivator F shown below is used as the hindered phenol-based metal deactivator.

‧「Metal Deactivator F」

Reagent name: Bis[3-(3-tertiarybutyl-4-hydroxy-5-methylphenyl)propionic acid][ethylene bis(oxyethylene)]; CAS No.36443-68-2

[Table 119]

In the case of using the fluxes of the blending examples (F12-1) to (F12-7) with respect to the solder powder having the alloy composition shown in Test Example 1, the flux of the blending example (F12-8) is used. Compared with the case, it can be confirmed that the effect of thickening suppression is improved.

Among them, the solder paste containing the solder powder with the alloy composition of Test Example 1 and the fluxes of the blending examples (F12-1) to (F12-7) is an implementation type solder paste containing flux (F12) .

Next, for the solder powders having the alloy compositions shown in Test Examples 2 to 258 and Test Examples 301 to 354, each of the fluxes of the blending examples (F12-1) to (F12-8) was used, and the above-mentioned < Evaluation of the change of viscosity in solder paste over time>, <Evaluation of △T> and <Evaluation of wettability>, as well as <Evaluation of viscosity increase inhibition> and <Evaluation of wettability>.

From the results of this evaluation, it can be confirmed that in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 2 to 258, the viscosity increase suppression effect, the narrowing of ΔT, and the excellent wettability are shown. Among them, the solder paste containing each solder powder with the alloy composition of Test Examples 2 to 258 and the fluxes of the blending examples (F12-1) to (F12-7) is an implementation that contains flux (F12) Type of solder paste.

On the other hand, in the case of the solder paste containing the solder powder having the alloy composition of Test Examples 301 to 354, at least one of the viscosity increasing suppression effect, the narrowing of ΔT, and the excellent wettability is poor. result.

In addition, in the case of using the fluxes of the blending examples (F12-1) to (F12-7) with respect to the solder powders of test examples 2 to 258, and using the flux of blending example (F12-8) In comparison, it can be confirmed that the effects of thickening suppression are improved.

In the solder pastes using the fluxes of the blending examples (F12-1) to (F12-7) to the solder powders of test examples 2 to 258, the solder paste further contains 0.1% by mass of particles relative to the total mass of the solder paste In the case of zirconia powder with a diameter of 1 μm, an improvement in the effect of suppressing thickening can be confirmed.

[Industrial Applicability]

According to the present invention, it is possible to provide a solder paste that does not easily cause changes over time such as a rise in viscosity, is excellent in wettability, and has high mechanical properties, in addition to improving various properties.

In addition, according to the present invention, by combining with a specific solder powder and selecting the blended components, it is possible to provide a further improvement in the wetting speed of the solder, corrosion inhibition of the metal surface (for example, copper plate) of the joining object, and printability. Flux for solder paste with various characteristics such as improved lifting and void suppression.

Claims (47)

A solder paste containing solder powder and flux, The aforementioned solder powder system contains a solder alloy which has at least one of As: 10 mass ppm or more but less than 40 mass ppm, Bi: 0 to 25,000 mass ppm, and Pb: 0 to 8,000 mass ppm, and the remainder Part of the alloy composition is composed of Sn, and satisfies the following formula (1) and (2), 300≦3As+Bi+Pb (1) 0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2) In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition. A solder paste containing solder powder and flux, The aforementioned solder powder contains a solder alloy having: As: 10 mass ppm or more and less than 40 mass ppm, Bi: more than 0 mass ppm and 25,000 mass ppm or less, and Pb: more than 0 mass ppm and 8,000 At least one of the mass ppm or less, and the remainder is an alloy composition composed of Sn, and satisfies the following formulas (1) and (2), 300≦3As+Bi+Pb (1) 0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2) In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition. A solder paste containing solder powder and flux, The aforementioned solder powder system contains a solder alloy having: As: 10 mass ppm or more and less than 40 mass ppm, and Bi: 50 to 25,000 mass ppm and Pb: more than 0 mass ppm and It is at least one of 8000 mass ppm or less, and the remainder is an alloy composition composed of Sn, and satisfies the following formulas (1) and (2), 300≦3As+Bi+Pb (1) 0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2) In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition. A solder paste containing solder powder and flux, The aforementioned solder powder contains a solder alloy having: As: 10 mass ppm or more and less than 40 mass ppm, Bi: more than 0 mass ppm and 25,000 mass ppm or less, and Pb: 50 to 8000 mass ppm At least one, and the remainder is the alloy composition composed of Sn, and satisfies the following formulas (1) and (2), 300≦3As+Bi+Pb (1) 0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2) In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition. A solder paste containing solder powder and flux, The aforementioned solder powder system contains a solder alloy having: As: 10 mass ppm or more and less than 40 mass ppm, and at least one of Bi: 50 to 25,000 mass ppm and Pb: 50 to 8,000 mass ppm, and The remaining part is the alloy composition composed of Sn, and satisfies the following (1) and (2) formulas, 300≦3As+Bi+Pb (1) 0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2) In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition. The solder paste according to any one of claims 1 to 5, wherein the aforementioned alloy composition further contains Ni: 0 to 600 ppm by mass. The solder paste according to any one of claims 1 to 5, wherein the aforementioned alloy composition further contains Fe: 0 to 100 ppm by mass. The solder paste according to any one of claims 1 to 5, wherein the aforementioned alloy composition further contains In: 0 to 1200 ppm by mass. The solder paste according to any one of claims 1 to 5, wherein the aforementioned alloy composition further contains at least two of Ni: 0 to 600 mass ppm, Fe: 0 to 100 mass ppm, and In: 0 to 1200 mass ppm . The solder paste according to any one of claims 1 to 5, wherein the aforementioned alloy composition further contains Ni: 0 to 600 mass ppm and Fe: 0 to 100 mass ppm, and satisfies the following formula (3), 0≦Ni/Fe≦50 (3) In the above formula (3), Ni and Fe each represent the content (mass ppm) in the aforementioned alloy composition. The solder paste according to any one of claims 1 to 10, wherein the aforementioned alloy composition further satisfies the following formula (1a), 300≦3As+Bi+Pb≦25114 (1a) In the above formula (1a), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition. The solder paste according to any one of claims 1 to 11, wherein the aforementioned alloy composition further contains at least one of Ag: 0 to 4% by mass and Cu: 0 to 0.9% by mass. The solder paste according to any one of claims 1 to 12, wherein As in the aforementioned alloy composition is 10 mass ppm or more and less than 25 mass ppm. The solder paste according to any one of claims 1 to 13, wherein the aforementioned flux contains a resin component, an active component, and a solvent. The solder paste according to claim 14, wherein the aforementioned flux contains a hindered phenolic compound. The solder paste according to claim 15, wherein the content of the hindered phenol compound is 0.5% by mass or more and 10% by mass or less with respect to the total mass of the flux. The solder paste according to claim 14, wherein the aforementioned flux contains a metal deactivator which is a nitrogen compound. The solder paste according to claim 17, wherein the metal deactivator is selected from the group consisting of Hydrazide-based nitrogen compounds, amide-based nitrogen compounds, triazole-based nitrogen compounds, and melamine-based nitrogen compounds At least one nitrogen compound in the group. The solder paste according to claim 17 or 18, wherein the content of the metal deactivator relative to the total mass of the flux is more than 0% by mass and 10% by mass or less. The solder paste according to claim 14, wherein the aforementioned flux contains acid-modified rosin. The solder paste according to claim 20, wherein the acid-modified rosin is selected from acrylic acid-modified rosin, acrylic acid-modified hydrogenated rosin, maleic acid-modified rosin, and maleic acid-modified hydrogenated rosin At least 1 in the group. The solder paste according to claim 20 or 21, wherein the content of the acid-modified rosin relative to the total mass of the flux is 3% by mass or more and 60% by mass or less. The solder paste according to claim 14, wherein the flux contains acrylic resin. The solder paste according to claim 23, wherein the content of the acrylic resin is 5% by mass or more and 50% by mass or less with respect to the total mass of the flux. The solder paste according to claim 14, wherein the aforementioned flux contains: a dimer acid selected from the group consisting of reactants of monocarboxylic acid and a dimer, and a hydrogenated dimer acid obtained by adding hydrogen to the dimer acid At least one organic compound in the group consisting of a polymer acid, a trimer acid that is a reactant of a monocarboxylic acid and is a trimer, and a hydrogenated trimer acid obtained by adding hydrogen to the trimer acid acid. The solder paste according to claim 25, wherein at least one organic acid selected from the group consisting of the aforementioned dimer acid, the aforementioned hydrogenated dimer acid, the aforementioned trimer acid, and the aforementioned hydrogenated trimer acid The content is 0.5% by mass or more and 20% by mass or less relative to the total mass of the aforementioned flux. The solder paste according to claim 14, wherein the aforementioned flux contains a compound represented by the following general formula (1),

In the formula (1), R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The solder paste according to claim 27, wherein the compound represented by the aforementioned general formula (1) is picolinic acid (Picolinic Acid). The solder paste according to claim 27 or 28, wherein the content of the compound represented by the general formula (1) is 0.5% by mass to 7% by mass relative to the total mass of the flux. The solder paste according to claim 14, wherein the aforementioned flux contains Azole. The solder paste according to claim 30, wherein the aforementioned azoles are selected from 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecylimidazole, benzimidazole and 2-octylbenzene At least one of the group consisting of bisimidazole. The solder paste according to claim 30 or 31, wherein the content of the azole is 0.1% by mass to 10% by mass relative to the total mass of the flux. The solder paste according to claim 14, wherein the aforementioned flux contains an aromatic guanidine compound. The solder paste according to claim 33, wherein the aromatic guanidine compound is at least one selected from the group consisting of diphenyl guanidine and ditolyl guanidine. The solder paste according to claim 33 or 34, wherein the content of the aromatic guanidine compound relative to the total mass of the flux is 0.2% by mass or more and 15% by mass or less. The solder paste according to claim 14, wherein the aforementioned flux contains an amide-based thixotropic viscosity reducer which is an amide compound. The solder paste according to claim 36, wherein the aforementioned amide-based thixotropic viscosity-reducing agent is at least one selected from the group consisting of polyamide, bisamide, and monoamide. The solder paste according to claim 36 or 37, wherein the content of the amide-based thixotropic agent is greater than 0% by mass and 15% by mass or less with respect to the total mass of the flux. The solder paste according to claim 14, wherein the aforementioned flux contains a sorbitol-based thixotropic viscosity reducer which is a Sorbitol compound. The solder paste according to claim 39, wherein the aforementioned sorbitol-based thixotropic agent is selected from the group consisting of benzhydryl sorbitol and bis(4-methylbenzylidene) sorbitol At least one of them. The solder paste according to claim 39 or 40, wherein the content of the sorbitol-based thixotropic viscosity reducing agent is 0.2% by mass to 5% by mass relative to the total mass of the flux. The solder paste according to claim 14, wherein the aforementioned flux contains both a glycol solvent and an organic acid ester. The solder paste according to claim 14, wherein the aforementioned flux includes a glycol solvent and a monohydric alcohol having 16 to 18 carbon atoms. The solder paste according to any one of claims 1 to 43, which further contains zirconia powder. The solder paste according to claim 44, wherein the content of the zirconia powder is 0.05 to 20.0% by mass relative to the total mass of the solder paste. A flux for solder paste, which is a flux for solder paste used in solder paste, The aforementioned solder paste contains a solder powder containing a solder alloy, the solder alloy having: As: 10 mass ppm or more and less than 40 mass ppm, and Bi: 0 to 25,000 mass ppm and Pb: 0 to 8000 mass ppm at least 1 type, and the remainder is the alloy composition composed of Sn, and satisfies the following formula (1) and (2), 300≦3As+Bi+Pb (1) 0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2) In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition. A flux for solder paste, which is a flux for solder paste used in solder paste, The aforementioned solder paste contains a solder powder containing a solder alloy. The solder alloy has: As: more than 10 mass ppm and less than 40 mass ppm, and Bi: more than 0 mass ppm and less than 25,000 mass ppm, and Pb: more than 0 mass ppm and at least one of 8000 mass ppm or less, and the remainder is an alloy composition composed of Sn, and satisfies the following formulas (1) and (2), 300≦3As+Bi+Pb (1) 0<2.3×10 ^-4 ×Bi+8.2×10 ^-4 ×Pb≦7 (2) In the above formulas (1) and (2), As, Bi, and Pb each represent the content (mass ppm) in the aforementioned alloy composition.