JP6469623B2 - Solder composition for jet dispenser - Google Patents

Description

  The present invention relates to a solder composition for a jet dispenser for application by a jet dispenser.

  In an electronic device, when connecting an electronic component and a wiring board, a solder composition (so-called solder paste) is used. This solder composition is a mixture obtained by kneading solder powder, a rosin resin, an activator, a solvent and the like into a paste. This solder composition can be formed on a wiring board and then subjected to a reflow process to form solder bumps. Here, a screen printing method or the like is generally used as the application format, but application in various application formats is required, and in recent years, application with a jet dispenser is required. Such a jet dispenser is effective for coating an uneven cavity substrate or a film substrate that is difficult to print.

However, for example, when trying to apply the solder composition for the screen printing method with a jet dispenser, there is a problem that the viscosity is too high or the thixotropy is too low to be applied properly.
In order to solve such a problem, for example, a solder composition for a jet dispenser containing a flux containing a rosin resin, an activator and a specific solvent and a solder powder has been proposed. In this solder composition, (C1) hexyl diglycol as a specific solvent, and (C2) an ester compound of a dicarboxylic acid having 8 to 12 carbon atoms and an alcohol having 4 to 12 carbon atoms, and (C3) It contains at least one selected from the group consisting of alcohols derived from gum turpentine oil (see Patent Document 1).

JP, 2015-047616, A

  The solder composition for a jet dispenser described in Patent Document 1 has sufficient applicability when applied by a jet dispenser, and can suppress solder scattering and flux separation. However, further suppression of solder scattering has been demanded, and the jet dispenser solder composition described in Patent Document 1 has not yet been sufficient.

  Then, an object of this invention is to provide the solder composition for jet dispensers which has sufficient applicability | paintability and can fully suppress solder scattering, when apply | coating with a jet dispenser.

In order to solve the above problems, the present invention provides the following solder composition for a jet dispenser.
That is, the solder composition for a jet dispenser of the present invention comprises (A) a rosin resin, (B) an activator, (C) a solvent and (D) a flux composition containing a thixotropic agent, and (E) a solder powder. containing, by immersing the measuring bar in the solder composition, a value obtained by spinnability test pulling the measuring bar at a speed of 500 mm / min is state, and are more than 100mm 42mm, the spinnability test But,
(I) The solder composition is stirred for 30 seconds at a rotation speed of 10 rpm,
(Ii) Immerse the measuring rod having the thread portion in the solder composition at a temperature of 25 ° C. so that the entire thread portion is immersed,
(Iii) Pulling up the measuring rod at a speed of 500 mm / min, and at this time,
It is a test to measure the length (mm) when the yarn formed between the solder composition is cut,
The kite portion includes a conical cone portion at the tip, a cylindrical column portion, and a connecting portion that connects the column portion and the measuring rod, and the diameter of the conical portion and the column portion is 10 mm. And the height of the conical portion is 5 mm, the length of the cylindrical portion is 9 mm, and the length of the connecting portion is 3 mm .

In the solder composition for jet dispensers of the present invention, the viscosity at 35 ° C. measured by an E-type viscometer of the solder composition is 5 Pa · s to 30 Pa · s, and the E-type viscometer of the solder composition It is preferable that the thixo index measured by the above is 0.60 or more and 0.90 or less.

In the solder composition for jet dispensers of the present invention, the component (A) preferably contains (A1) a hydrogenated product of an unsaturated organic acid-modified rosin and (A2) a fully hydrogenated rosin.
In the solder composition for jet dispensers of the present invention, the component (C) contains (C1) diethylene glycol monohexyl ether, and (C2) a dicarboxylic acid having 8 to 12 carbon atoms and 4 to 12 carbon atoms. It is preferable to contain at least one selected from the group consisting of an ester compound with alcohol and an alcohol derived from gum turpentine oil.
In the solder composition for jet dispensers of the present invention, the component (D) preferably contains (D1) an amide thixotropic agent.

  ADVANTAGE OF THE INVENTION According to this invention, when apply | coating with a jet dispenser, it has sufficient applicability | paintability and can provide the solder composition for jet dispensers which can fully suppress solder scattering.

It is explanatory drawing for demonstrating the method of a spinnability test. It is explanatory drawing for demonstrating the method of a spinnability test. It is the schematic which shows a jet dispenser.

  The solder composition for jet dispensers of this invention contains the flux composition demonstrated below and the (E) solder powder demonstrated below.

In this invention, the value calculated | required by the spinnability test which immerses a measuring rod in this solder composition and pulls up the said measuring rod at a speed | rate of 500 mm / min needs to be 42 mm or more. When the value obtained by this spinnability test is less than 42 mm, solder splattering cannot be sufficiently suppressed when applied by a jet dispenser. In addition, the present inventors have found that there is a correlation between the value obtained in the spinnability test and the evaluation result of the solder scattering, and completed the present invention based on this knowledge. Moreover, since evaluation of solder scattering needs to actually apply several thousand places and observe it, a very long test time is required. On the other hand, if it is the said spinnability test, it can be performed in a short time and an experiment becomes easy in order to further improve solder scattering.
Further, from the viewpoint of more reliably suppressing solder scattering, the value obtained by the spinnability test is preferably 45 mm or more. In addition, although the upper limit of the value calculated | required by a spinnability test is not specifically limited, For example, it is 100 mm or less.

The spinnability test can be measured by the following method. That is, first, as shown in FIG. 1, the solder composition 2 is put into the container 3, and (i) the solder composition 2 is stirred for 30 seconds at a rotation speed of 10 rpm. Thereafter, (ii) the measuring rod 1 having the thread portion 11 (see FIG. 2) in the solder composition 2 is immersed so that the entire thread portion 11 is immersed. Thereafter, (iii) the measuring rod 1 is pulled up at a speed of 500 mm / min, and at this time, the length (mm) when the yarn formed between the thread portion 11 and the solder composition 2 is cut is measured. It is a test to do.
As shown in FIG. 2, the kite string portion 11 includes a conical conical portion 11A, a columnar cylindrical portion 11B, and a connecting portion 11C that connects the cylindrical portion 11B and the measuring rod 1 at the tip.
The diameter D1 of the conical portion 11A and the cylindrical portion 11B is 10 mm, the height H of the conical portion 11A is 5 mm, the length L1 of the cylindrical portion 11B is 9 mm, and the length L2 of the connecting portion 11C is 3 mm. It is. Furthermore, the diameter D2 of the measuring rod 1 is 3 mm.

In the present invention, the viscosity at 35 ° C. measured by an E-type viscometer of the solder composition is
It is preferably 5 Pa · s or more and 30 Pa · s or less, and more preferably 10 Pa · s or more and 25 Pa · s or less. If the viscosity is within the above range, sufficient coating properties can be maintained when coating with a jet dispenser.
In the present invention, the thixo index measured by an E-type viscometer of the solder composition is preferably 0.60 or more and 0.90 or less, and more preferably 0.65 or more and 0.85 or less. . If the thixo index is within the above range, sufficient coating properties can be maintained when coating with a jet dispenser.
The viscosity and thixo index can be measured with an E-type viscometer according to JIS Z3284 appendix 6.

In addition, the following methods are mentioned as a method of adjusting the value calculated | required by the spinnability test of a solder composition, a viscosity, and a thixo index to the range mentioned above.
The value calculated | required by a spinnability test can be adjusted by changing the kind and compounding quantity of a rosin resin, a solvent, and a thixotropic agent. For example, when polymerized rosin or the like is used as the rosin resin, the value required in the spinnability test tends to be low. When a glycerin ester-based thixotropic agent or a benzylidene sorbitol-based thixotropic agent is used as the thixotropic agent, the value required in the spinnability test tends to be low.
Viscosity and thixo index can all be adjusted by changing the types and amounts of rosin resin, solvent and thixotropic agent.

[Flux composition]
The flux composition used in the present invention is a component other than the component (E) in the solder composition, and contains (A) a rosin resin, (B) an activator, (C) a solvent, and (D) a thixotropic agent. Is.

  The blending amount of the flux composition is preferably 10% by mass to 25% by mass, more preferably 12% by mass to 20% by mass, and more preferably 14% by mass with respect to 100% by mass of the solder composition. % To 18% by mass is particularly preferable. When the blending amount of the flux is less than 10% by mass (when the blending amount of the solder powder exceeds 90% by mass), the applicability with the jet dispenser tends to be insufficient. On the other hand, the blending amount of the flux is When it exceeds 25 mass% (when the blending amount of the solder powder is less than 75 mass%), when the obtained solder composition is used, it tends to be difficult to form a sufficient solder joint.

[(A) component]
Examples of the (A) rosin resin used in the present invention include rosins and rosin modified resins. Examples of rosins include gum rosin, wood rosin and tall oil rosin. Examples of rosin-based modified resins include disproportionated rosin, polymerized rosin, hydrogenated rosin (fully hydrogenated rosin, partially hydrogenated rosin, and unsaturated organic acids (aliphatic unsaturated monobasic such as (meth) acrylic acid). Unsaturated organics that are modified rosins of acid, fumaric acid, maleic acid and other aliphatic unsaturated dibasic acids such as α, β-unsaturated carboxylic acids, and unsaturated carboxylic acids having aromatic rings such as cinnamic acid) Examples include hydrogenated products of acid-modified rosin (also referred to as “hydrogenated acid-modified rosin”) and derivatives thereof. These rosin resins may be used alone or in combination of two or more.

In the present invention, from the viewpoint of increasing the value required in the spinnability test, (A) a rosin resin, (A1) a hydrogenated product of an unsaturated organic acid-modified rosin, (A2) a fully hydrogenated rosin, It is preferable to use together. The blending amount of the component (A1) is preferably 30% by mass or more and 90% by mass or less, and 40% by mass with respect to 100% by mass of the total amount of the component (A1) and the component (A2). It is more preferably 85% by mass or less, and particularly preferably 50% by mass or more and 80% by mass or less.
The component (A) may contain a rosin resin (component (A3)) other than the component (A1) and the component (A2) as long as it does not affect the object of the present invention. Good. However, when using this (A3) component, the compounding quantity is preferably 30% by mass or less, more preferably 20% by mass or less, and more preferably 10% by mass with respect to 100% by mass of the (A) component. % Or less is particularly preferable.
The polymerized rosin is preferably not used because the value required in the spinnability test of the solder composition tends to decrease.

  The blending amount of the component (A) is preferably 25% by mass or more and 60% by mass or less, more preferably 30% by mass or more and 55% by mass or less, with respect to 100% by mass of the flux composition. It is particularly preferable that the content is not less than mass% and not more than 52 mass%. If the blending amount of the component (A) is equal to or more than the lower limit, the so-called solderability can be improved by preventing the copper foil surface of the soldered land from being oxidized and making the surface of the solder solder wet easily. Can be suppressed. Moreover, if the compounding quantity of (A) component is below the said upper limit, flux residual quantity can fully be suppressed.

[Component (B)]
Examples of the activator (B) used in the present invention include an organic acid, a non-dissociative activator comprising a non-dissociable halogenated compound, and an amine-based activator. These activators may be used individually by 1 type, and may mix and use 2 or more types.
Examples of the organic acid include other organic acids in addition to monocarboxylic acid and dicarboxylic acid.
Monocarboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, capric acid, lauric acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, tuberculostearic acid Arachidic acid, behenic acid, lignoceric acid, glycolic acid and the like.
Examples of the dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, tartaric acid, diglycolic acid and the like.
Examples of other organic acids include dimer acid, levulinic acid, lactic acid, acrylic acid, benzoic acid, salicylic acid, anisic acid, citric acid, and picolinic acid.

  Examples of the non-dissociable activator comprising the non-dissociable halogenated compound include non-salt organic compounds in which halogen atoms are bonded by a covalent bond. The halogenated compound may be a compound formed by covalent bonding of chlorine, bromine and fluorine, such as chlorinated, brominated and fluoride, but any two or all of chlorine, bromine and fluorine may be used. The compound which has the following covalent bond may be sufficient. In order to improve the solubility in an aqueous solvent, these compounds preferably have a polar group such as a hydroxyl group or a carboxyl group such as a halogenated alcohol or a halogenated carboxyl. Examples of the halogenated alcohol include 2,3-dibromopropanol, 2,3-dibromobutanediol, trans-2,3-dibromo-2-butene-1,4-diol (TDBD), and 1,4-dibromo-2. -Brominated alcohols such as butanol and tribromoneopentyl alcohol, chlorinated alcohols such as 1,3-dichloro-2-propanol and 1,4-dichloro-2-butanol, fluorinated alcohols such as 3-fluorocatechol, and others The compound similar to these is mentioned. Examples of the halogenated carboxyl include 2-iodobenzoic acid, 3-iodobenzoic acid, 2-iodopropionic acid, 5-iodosalicylic acid, 5-iodoanthranilic acid, etc., 2-chlorobenzoic acid, 3-chloropropion Examples thereof include carboxyl chloride such as acid, brominated carboxyl such as 2,3-dibromopropionic acid, 2,3-dibromosuccinic acid and 2-bromobenzoic acid, and other similar compounds.

  Examples of the amine activator include amines (polyamines such as ethylenediamine), amine salts (amines such as trimethylolamine, cyclohexylamine, diethylamine, and organic acid salts such as amino alcohols and inorganic acid salts (hydrochloric acid, sulfuric acid, odors). Hydroacid, etc.)), amino acids (glycine, alanine, aspartic acid, glutamic acid, valine, etc.), amide compounds and the like. Specifically, diphenylguanidine hydrobromide, cyclohexylamine hydrobromide, diethylamine salt (hydrochloride, succinate, adipate, sebacate, etc.), triethanolamine, monoethanolamine, etc. And the hydrobromide of the amine.

  The blending amount of the component (B) is preferably 0.1% by mass or more and 15% by mass or less, and 0.5% by mass or more and 10% by mass or less with respect to 100% by mass of the flux composition. Is more preferable. If the blending amount of component (B) is equal to or greater than the lower limit, solder balls can be more reliably suppressed. Moreover, if the compounding quantity of (B) component is below the said upper limit, the insulation of a flux composition is securable.

[Component (C)]
As the (C) solvent used in the present invention, it is preferable to use a combination of the components (C1) and (C2) described below.
The component (C1) is diethylene glycol monohexyl ether, and a known one can be used as appropriate.

The component (C2) is at least one selected from the group consisting of ester compounds of dicarboxylic acids having 8 to 12 carbon atoms and alcohols having 4 to 12 carbon atoms and alcohols derived from gum turpentine oil. .
Among the ester compounds, an ester compound of a dicarboxylic acid having 8 to 10 carbon atoms and an alcohol having 6 to 10 carbon atoms is more preferable, and an ester compound of a dicarboxylic acid having 10 carbon atoms and an alcohol having 8 carbon atoms is particularly preferable. Specific examples include bis (2-ethylhexyl) sebacate (DOS) and bis (2-ethylhexyl) azelate.
As said alcohol, a well-known thing can be used suitably. Specifically, α, β, γ-terpineol and the like can be mentioned.
The (C) solvent may contain a solvent other than the component (C1) and the component (C2) as long as it does not affect the object of the present invention. However, when other solvents are used, the blending amount is preferably 30% by mass or less, more preferably 20% by mass or less, and more preferably 10% by mass with respect to 100% by mass of the component (C). It is particularly preferred that

The blending amount of the component (C) is preferably 30% by mass to 60% by mass and more preferably 35% by mass to 55% by mass with respect to 100% by mass of the flux composition. When the blending amount of the component (C) is equal to or more than the lower limit, the viscosity and thixotropy of the solder composition can be easily adjusted to an appropriate range. On the other hand, if the blending amount of the component (C) is less than or equal to the above upper limit, the solvent is less likely to remain in the residual flux remaining when the solder composition is melted, and the residual flux has adhesiveness and floats in the air. It is possible to sufficiently prevent the occurrence of electric leakage due to the adhesion of dust or dust.
The blending amount of the component (C1) is preferably 20% by mass or more and 80% by mass or less, and 30% by mass with respect to 100% by mass of the total amount of the component (C1) and the component (C2). The content is more preferably 70% by mass or less, and particularly preferably 40% by mass or more and 60% by mass or less. If the compounding quantity of (C1) component is more than the said minimum, the thixotropy of a solder composition is securable. On the other hand, if the blending amount of the component (C1) is not more than the above upper limit, the effect of suppressing solder scattering can be ensured.

[(D) component]
The (D) thixotropic agent used in the present invention preferably contains (D1) an amide thixotropic agent. According to this (D1) component, it exists in the tendency which can improve a viscosity and thixotropy, suppressing the raise of the yield value of a solder composition.
As the component (D1), N, N′-hexamethylene bishydroxystearic acid amide, N, N′-ethylene bisstearic acid amide, N, N′-ethylene biscapric acid amide, N, N′-ethylene bis Lauric acid amide, N, N′-ethylenebisbehenic acid amide, N, N′-hexamethylenebisstearic acid amide, N, N′-hexamethylenebisbehenic acid amide, N, N′-distearyl adipic acid amide, N, N'-distearyl sebacic acid amide, N, N'-ethylenebisoleic acid amide, N, N'-ethylenebiserucic acid amide, N, N'-hexamethylenebisoleic acid amide, N, N'- Dioleyl adipic acid amide, N, N′-dioleyl sebacic acid amide, N, N′-m-xylylenebisstearic acid amide, N, N′-m-xylylene Examples thereof include bishydroxystearic acid amide and N, N′-distearylisophthalic acid amide. Among these, N, N′-hexamethylenebishydroxystearic acid amide and N, N′-ethylenebisstearic acid amide are preferable from the viewpoint of the yield value of the solder composition. These may be used alone or in combination of two or more.
The component (D) may contain another thixotropic agent (component (D2)) other than the component (D1) as long as the object of the present invention is not affected. However, when using this (D2) component, the compounding quantity is preferably 30% by mass or less, more preferably 20% by mass or less, and more preferably 10% by mass with respect to 100% by mass of the (D) component. % Or less is particularly preferable.
Examples of the component (D2) include glycerin ester thixotropic agents (such as hardened castor oil) and inorganic thixotropic agents (such as kaolin, colloidal silica, organic bentonite, and glass frit). These may be used alone or in combination of two or more.
Note that it is preferable not to use a glycerin ester thixotropic agent or a benzylidene sorbitol thixotropic agent because the value required in the spinnability test of the solder composition tends to decrease.

  The blending amount of the component (D) is preferably 3% by mass to 15% by mass, and more preferably 5% by mass to 10% by mass with respect to 100% by mass of the flux composition. If the compounding quantity of (D) component is more than the said minimum, sufficient thixotropy will be acquired and dripping can fully be suppressed. On the other hand, if the blending amount of the component (D) is less than or equal to the above upper limit, the thixotropy is too high and no coating failure occurs.

[Other ingredients]
In addition to the component (A), the component (B), the component (C) and the component (D), the flux composition used in the present invention, if necessary, other additives, Other resins can be added. Examples of other additives include antioxidants, antifoaming agents, modifiers, matting agents, and foaming agents. Examples of other resins include acrylic resins.

[(E) component]
The solder powder (E) used in the present invention is preferably composed of only lead-free solder powder, but may be lead-lead solder powder. As the solder alloy in the solder powder, an alloy containing tin as a main component is preferable. Examples of the second element of the alloy include silver, copper, zinc, bismuth, and antimony. Furthermore, you may add another element (after 3rd element) to this alloy as needed. Examples of other elements include copper, silver, bismuth, antimony, aluminum, and indium.
Specific examples of the lead-free solder powder include Sn / Ag, Sn / Ag / Cu, Sn / Cu, Sn / Ag / Bi, Sn / Bi, Sn / Ag / Cu / Bi, Sn / Sb, Sn / Zn / Bi, Sn / Zn, Sn / Zn / Al, Sn / Ag / Bi / In, Sn / Ag / Cu / Bi / In / Sb, In / Ag, and the like.

  The average particle size of the solder powder is preferably 1 μm or more and 40 μm or less, more preferably 10 μm or more and 35 μm or less, and particularly preferably 15 μm or more and 25 μm or less. If the average particle diameter is within the above range, it can be applied to the recent printed wiring board in which the pitch of the soldering lands is narrow. The average particle size can be measured with a dynamic light scattering type particle size measuring device.

[Method for producing solder composition]
The solder composition for a jet dispenser of the present invention can be produced by blending the above-described flux composition and the above-described (E) solder powder in the above-mentioned predetermined ratio, and stirring and mixing them.

[Connection method using solder composition]
Next, the connection method of electrodes, such as a wiring board and an electronic component, using the solder composition for jet dispensers of this invention is demonstrated. Here, the case where the electrodes of the wiring board and the electronic component are connected will be described as an example.
Thus, as a method of connecting the electrodes of the wiring board and the electronic component, an application step of applying the solder composition on the wiring board, and arranging the electronic component on the solder composition, and using a reflow furnace And a reflow process of heating the electronic component on the wiring board under a predetermined condition.

In the applying step, the solder composition is applied onto the wiring board.
The coating apparatus used here is a jet dispenser 4 as shown in FIG. The jet dispenser 4 includes a syringe 41, a nozzle 42, a needle 43, and a valve 44. When the solder composition is discharged by the jet dispenser 4, first, the solder composition is supplied from the syringe 41, and the nozzle 42 is filled with the solder composition. Then, the needle 43 is pushed downward in FIG. 3 by the valve 44, and the solder composition in the nozzle 42 is discharged.
The solder composition for a jet dispenser of the present invention has excellent applicability, and can be satisfactorily applied with such a jet dispenser.

In the reflow process, the electronic component is placed on the solder composition and heated in a reflow furnace under predetermined conditions. By this reflow process, sufficient soldering can be performed between the electronic component and the wiring board. As a result, the electronic component can be mounted on the wiring board.
What is necessary is just to set reflow conditions suitably according to melting | fusing point of solder. For example, when using a Sn—Au—Cu-based solder alloy, preheating may be performed at a temperature of 150 to 180 ° C. for 60 to 120 seconds, and a peak temperature may be set to 240 to 250 ° C.

In addition, the connection method using the solder composition of the present invention is not limited to the connection method described above, and modifications, improvements and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the connection method, the wiring board and the electronic component are bonded by the reflow process, but the present invention is not limited to this. For example, instead of the reflow process, the wiring board and the electronic component may be bonded by a process of heating the solder composition using laser light (laser heating process). In this case, the laser light source is not particularly limited, and can be appropriately selected according to the wavelength matched to the metal absorption band. As the laser light source, for example, a solid laser (ruby, glass, YAG, etc.), semiconductor laser (GaAs, InGaAsP, etc.), (such as a dye) liquid laser, a gas laser (He-Ne, Ar, CO 2, etc. excimer) is Can be mentioned.

EXAMPLES Next, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited at all by these examples. In addition, the material used in the Example and the comparative example is shown below.
((A1) component)
Rosin resin A: hydrogenated acid-modified rosin, trade name “KE-604”, manufactured by Arakawa Chemical Industries, Ltd. (component (A2))
Rosin resin B: Completely hydrogenated rosin, trade name “Foral AX”, manufactured by Sojitz Corporation (component (A3))
Rosin resin C: Polymerized rosin, trade name “China Polymerized Rosin 140”, manufactured by Arakawa Chemical Industries, Ltd. (component (B))
Activator A: Succinic acid activator B: Glutaric acid activator C: Dimer acid, trade name “UNIDYME14”, manufactured by Arizona Chemical Co. (component (C1))
Solvent A: Diethylene glycol monohexyl ether, manufactured by Nippon Emulsifier Co., Ltd. (component (C2))
Solvent B: α, β, γ-Terpineol, trade name “Tarpineol C”, manufactured by Nippon Terpene Chemical Co., Ltd. (component (C3))
Solvent C: Octanediol (component (D1))
Thixotropic agent A: N, N′-hexamethylenebishydroxystearic acid amide, trade name “Sripacs ZHH”, Nippon Kasei Co., Ltd. thixotropic agent B: higher fatty acid polyamide, trade name “Tarren ATX-1146”, manufactured by Kyoeisha Chemical Co., Ltd. (D2) component)
Thixotropic agent C: hydrogenated castor oil, trade name “castor”, manufactured by KF Trading (component (E))
Solder powder: average particle size 18 μm, solder melting point 216-220 ° C., solder composition Sn / Ag / Cu
(Other ingredients)
Antioxidant: Trade name “Irganox 245”, manufactured by BASF

[Example 1]
36% by mass of rosin resin A, 6.5% by mass of rosin resin B, 7% by mass of thixotropic agent A, 4% by mass of antioxidant, 1% by mass of activator A, 3% by mass of activator B, 5% by mass of activator C, 11% by mass of solvent A11 % And Solvent B 26.5% by mass were respectively charged into a container and mixed with a kneader (planetary mixer) while being heated to 160 ° C. with a mantle heater to obtain a flux composition.
Thereafter, 17% by mass of the obtained flux composition and 83% by mass of solder powder (100% by mass in total) were put into a container and mixed in a kneader (planetary mixer), whereby the compositions shown in Table 1 below were obtained. A solder composition was prepared.
And the value calculated | required by the spinnability test of the obtained solder composition was measured. Specifically, the obtained solder composition in the container was charged, and the solder composition was stirred for 30 seconds at a rotation speed of 10 rpm. Thereafter, a measuring rod having a thread portion in the solder composition was immersed so that the entire thread portion was immersed. Thereafter, the measuring rod was pulled up at a speed of 500 mm / min, and at this time, the length (mm) when the yarn formed between the kite portion and the solder composition was cut was measured. The obtained results are shown in Table 1.
The diameter of the conical part and the cylindrical part is 10 mm, the height of the conical part is 5 mm, the length of the cylindrical part is 9 mm, the length of the connecting part is 3 mm, and the diameter of the measuring rod is 3 mm. It is. Further, “EZ-L” manufactured by SIMAZU was used as a device for lifting the measuring rod.
Further, the obtained solder composition was measured with an E-type viscometer in accordance with JIS Z3284 appendix 6. The viscosity value η (unit: mPa · s) was read at a rotation speed of 10 rpm and a temperature of 35 ° C. Further, in the same manner as described above, the viscosity value when the rotation speed was adjusted to 30 rpm (30 rpm viscosity) and the viscosity value when the rotation speed was adjusted to 3 rpm (3 rpm viscosity) were read. And the thixo index was computed based on the following formula. The obtained results are shown in Table 1.
Thixo index = log [(3 rpm viscosity) / (30 rpm viscosity)]

[Examples 2 and 3 and Comparative Examples 1 to 4]
A solder composition was obtained in the same manner as in Example 1 except that each material was blended according to the composition shown in Table 1.
Further, the obtained solder composition was measured in the same manner as in Example 1 for the value, viscosity, and thixo index determined by the spinnability test.

<Evaluation of solder composition>
The performance (applied shape, solder scattering) of the solder composition was evaluated or measured by the following method. The obtained results are shown in Table 1.
(1) Application shape and (2) Solder scattering (satellite)
Using a 10 mL syringe filled with 40 g of the solder composition and a jet dispenser having a nozzle with a diameter of 0.26 mmφ, the distance from the nozzle tip to the substrate was 1.5 mm, and the coating time per point was 0.09. 10000 points are ejected at equal intervals (100 points × 100 rows) within the range of 100 mm × 100 mm on the substrate (material: aluminum, size: 150 mm × 150 mm, thickness: 0.5 mm) To obtain a test substrate.
And the obtained test board | substrate was observed visually and the application | coating shape was evaluated according to the following references | standards.
○: The application shape is circular.
X: The application shape is elliptical or there is stringing.
Further, regarding the solder scattering, the obtained test substrate was agglomerated powder having a diameter of 70 μm or more present away from the discharged material as solder scattering, and the number (the number per 10,000 shots) was counted.

As is clear from the results shown in Table 1, when the jet dispenser solder composition of the present invention was used (Examples 1 to 3), the coating shape was good and the solder scattering was 5 in 10,000 shots. It was confirmed that it was very little as follows. From this, it was confirmed that the solder composition for jet dispensers of the present invention has sufficient applicability when applied by a jet dispenser and can sufficiently suppress solder scattering.
On the other hand, when the value calculated | required by the spinnability test of a solder composition is less than 42 mm (Comparative Examples 1-4), it turns out that solder scattering cannot fully be suppressed and an application | coating shape may be bad. It was.

  The solder composition for jet dispensers of the present invention can be suitably used as a technique for connecting an electronic component and a wiring board.

Claims (5)

A flux composition containing (A) a rosin resin, (B) an activator, (C) a solvent and (D) a thixotropic agent, and (E) a solder powder,
Immersing the measuring bar in the solder composition, the values determined the measuring bar in spinnability tests pulled at a speed of 500 mm / min is state, and are more than 100mm 42mm,
The spinnability test
(I) The solder composition is stirred for 30 seconds at a rotation speed of 10 rpm,
(Ii) Immerse the measuring rod having the thread portion in the solder composition at a temperature of 25 ° C. so that the entire thread portion is immersed,
(Iii) Pulling up the measuring rod at a speed of 500 mm / min, and at this time,
It is a test to measure the length (mm) when the yarn formed between the solder composition is cut,
The string portion includes a conical cone portion at a tip, a cylindrical column portion, and a connecting portion that connects the column portion and the measuring rod.
The diameter of the conical part and the cylindrical part is 10 mm, the height of the conical part is 5 mm, the length of the cylindrical part is 9 mm, and the length of the connecting part is 3 mm. Solder composition for jet dispenser. The jet dispenser solder composition according to claim 1 ,
The viscosity at 35 ° C. measured with an E-type viscometer of the solder composition is 5 Pa · s or more and 30 Pa · s or less,
A solder composition for a jet dispenser, wherein the solder composition has a thixo index measured by an E-type viscometer of 0.60 or more and 0.90 or less. In the solder composition for jet dispensers according to claim 1 or 2 ,
The component (A) contains (A1) a hydrogenated product of an unsaturated organic acid-modified rosin and (A2) a fully hydrogenated rosin. In the solder composition for jet dispensers according to any one of claims 1 to 3 ,
The component (C) is
(C1) containing diethylene glycol monohexyl ether, and
(C2) It contains at least one selected from the group consisting of ester compounds of C8-12 dicarboxylic acids and C4-12 alcohols, and alcohols derived from gum turpentine oil. A solder composition for a jet dispenser. In the solder composition for jet dispensers according to any one of claims 1 to 4 ,
The component (D) contains (D1) an amide thixotropic agent. A solder composition for a jet dispenser, wherein:

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