WO2019022193A1 - Solder paste flux, solder paste, method for forming solder bump using solder paste, and method for producing joined body - Google Patents

Solder paste flux, solder paste, method for forming solder bump using solder paste, and method for producing joined body Download PDF

Info

Publication number
WO2019022193A1
WO2019022193A1 PCT/JP2018/028062 JP2018028062W WO2019022193A1 WO 2019022193 A1 WO2019022193 A1 WO 2019022193A1 JP 2018028062 W JP2018028062 W JP 2018028062W WO 2019022193 A1 WO2019022193 A1 WO 2019022193A1
Authority
WO
WIPO (PCT)
Prior art keywords
solder
solder paste
flux
mass
paste
Prior art date
Application number
PCT/JP2018/028062
Other languages
French (fr)
Japanese (ja)
Inventor
司 八十嶋
石川　雅之
Original Assignee
三菱マテリアル株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2018133872A external-priority patent/JP6566095B2/en
Application filed by 三菱マテリアル株式会社 filed Critical 三菱マテリアル株式会社
Priority to KR1020197031518A priority Critical patent/KR102122166B1/en
Priority to CN201880027120.7A priority patent/CN110603120B/en
Publication of WO2019022193A1 publication Critical patent/WO2019022193A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K1/00—Soldering, e.g. brazing, or unsoldering
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
    • B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
    • B23K35/24—Selection of soldering or welding materials proper
    • B23K35/26—Selection of soldering or welding materials proper with the principal constituent melting at less than 400 degrees C
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
    • B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
    • B23K35/24—Selection of soldering or welding materials proper
    • B23K35/30—Selection of soldering or welding materials proper with the principal constituent melting at less than 1550 degrees C
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C11/00—Alloys based on lead
    • C22C11/06—Alloys based on lead with tin as the next major constituent
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C13/00—Alloys based on tin
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C5/00—Alloys based on noble metals
    • C22C5/02—Alloys based on gold
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/30—Assembling printed circuits with electric components, e.g. with resistor
    • H05K3/32—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
    • H05K3/34—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering

Definitions

  • the present invention relates to a flux for solder paste, a solder paste, a method of forming solder bumps using the solder paste, and a method of manufacturing a joined body, which can obtain a solder used when bonding an electronic component to a substrate.
  • solder paste composed of a solder powder and a flux containing rosin, a solvent, a thixotropic agent, and an activator is used for soldering.
  • a solder paste When forming a solder bump using such a solder paste, if a solder paste is applied on a substrate and reflowed, a residue based on rosin etc. remains on the upper surface of the solder, so this residue is cleaned with chemicals etc. Need to be complicated.
  • a flux free of residue after soldering and a solder paste containing the flux are known (see Patent Document 1).
  • Patent Document 1 Since the flux described in Patent Document 1 contains ammonium formate and an aliphatic polyhydric alcohol which is liquid at normal temperature and has a boiling point of 150 ° C. or more at atmospheric pressure, it has reducibility and is efficient. By reducing the oxide film well, the oxide film generated on the substrate etc. is removed. In the configuration of Patent Document 1, the residue of the flux after soldering the electronic component and the like to the substrate is suppressed.
  • a mask having an opening is disposed on a substrate, and a solder paste is printed so that a solder paste containing flux and solder powder is filled in the opening.
  • the halogen content of the flux is 0.03% by mass or less, and the reflow process is performed under a formic acid gas atmosphere and / or under an atmosphere of a gas in which formic acid is thermally decomposed.
  • the reflow process is performed in a formic acid gas atmosphere and / or in an atmosphere of a gas in which formic acid is thermally decomposed, thereby reducing an oxide film such as solder powder to smooth solder melting.
  • JP JP 2011-83809 A Japanese Patent Application Laid-Open No. 2016-78095 (A)
  • the present invention has been made in view of such circumstances, and it is possible to obtain a solder capable of suppressing generation of a residue, a flux for solder paste, a solder paste, a method of forming a solder bump using the solder paste, and a bonding body
  • the purpose is to provide a manufacturing method.
  • the flux for solder paste according to one embodiment of the present invention is a flux for solder paste containing a caking agent, a solvent, and a thixo agent, and has an acid value of 100 mg KOH / G or less, the reduction rate at 300 ° C. in thermogravimetry is 80 mass% or more, the viscosity is 0.5 Pa ⁇ s or more, and the tacking force is 1.0 N or more.
  • tacking force means the adhesive strength with respect to the board
  • the reduction rate at 300 ° C. in the thermogravimetric measurement of the flux for solder paste is 80 mass% or more, when the solder paste containing the flux for solder paste is reflowed, the volatile content is large as flux Even when the solder paste containing the flux for solder paste is reflowed to form a solder bump, generation of a residue can be suppressed. If the viscosity of the flux for solder paste is less than 0.5 Pa ⁇ s, the viscosity of the flux is too small to form a solder paste, and there is a possibility that the paste can not be applied to a substrate or the like.
  • the tacking force of the flux for solder paste is less than 1.0 N, the adhesive strength is low, so when the solder paste containing this flux is applied to a substrate or the like, the applied solder paste may slip off from the substrate or the like There is a risk of On the other hand, in the present invention, since the viscosity of the flux is 0.5 Pa ⁇ s or more and the tacking force is 1.0 N or more, the shape retention of the solder paste comprising the flux for solder paste and the solder powder I can secure the sex.
  • the acid value of the flux for solder paste 100 mg KOH / g or less, the reaction between the flux residue that may be slightly left and the surrounding metal portion, such as copper of the wiring, can be suppressed to suppress corrosion. It is possible to secure the long-term reliability of the assembly.
  • the reaction between the solder powder and the flux when forming the solder paste is suppressed, and the viscosity change as the solder paste is reduced, the solder paste which normally needs to be stored under refrigeration for a long time at room temperature (for example, Can be stored for more than 6 months, and can improve long-term storage performance.
  • the flux for solder paste of the present invention does not contain rosins and activators contained in ordinary flux, it is slightly contained in the range that satisfies the requirements of the above-mentioned thermogravimetry and acid value. It may be
  • the flux for solder pastes of this invention it is good for content of rosins to be 10 mass% or less. Even if the flux for solder paste contains rosins, the acid value of the flux for solder paste can be 100 mg KOH / g or less if the amount is 10 mass% or less. That is, the flux for solder paste does not prevent inclusion of rosins if it is in the range of 10% by mass or less.
  • the solder paste of the other aspect of the present invention (hereinafter referred to as "the solder paste of the present invention") is formed by mixing the flux for solder paste and a solder powder. Since the solder paste of the present invention contains the above-mentioned flux for solder paste, even when the solder paste is reflowed, the generation of residues can be suppressed, and the decrease in bonding caused by the residues remaining can be suppressed. .
  • the content of the flux for solder paste is preferably 30% by volume or more and 90% by volume or less. If the content of the solder paste flux is less than 30% by volume, the paste can not be formed or becomes a dry paste, and there is a possibility that the solder paste can not be applied to a substrate or the like. On the other hand, if the content of the flux for solder paste exceeds 90% by volume, the viscosity of the solder paste becomes too low, which may deteriorate the coating performance or the flux and the solder powder may be easily separated.
  • the content of the flux for solder paste is 30% by volume or more and 90% by volume or less, a solder paste having an appropriate viscosity can be formed, and the coating performance is deteriorated.
  • the solder powder is Sn—Ag—Cu solder powder, Sn—Cu solder powder, Sn—Ag solder powder, Pb—Sn solder powder, Au—Sn solder powder, Au— It may be either Ge solder powder or Au-Si solder powder. According to the above aspect, any of the above-mentioned various powders can be used as the solder powder.
  • the solder paste containing Au-Sn solder powder is a solder paste with a high melting point, and therefore the residue is likely to jump during reflow, but the flux for solder paste is used Since the generation of the residue is suppressed by doing this, it is possible to prevent the jump of the residue at the time of reflow.
  • a method for forming a solder bump using a solder paste according to another aspect of the present invention (hereinafter referred to as “a method for forming a solder bump using a solder paste according to the present invention”), a mask having an opening is arranged on a substrate The solder paste is printed so as to fill the solder paste in the opening, and after peeling off the mask, the bump precursor on the substrate is subjected to a reflow process in a formic acid gas atmosphere to form a solder bump.
  • the step of cleaning the solder bumps can be omitted by suppressing the generation of the above-mentioned residue, and the reflow process is performed in a formic acid gas atmosphere, so the oxide is reduced and removed. Even if rosins and the like are not contained, the oxide film on the substrate and the oxide film on the surface of the solder can be reduced to facilitate solder melting.
  • the method for producing a joined body using the solder paste according to another aspect of the present invention is a method for producing a joined body using a solder paste
  • the solder paste is placed between a joint and a workpiece, and the joint and the workpiece are solder-bonded by heating in a formic acid gas atmosphere. According to such a configuration, it is possible to omit the step of cleaning the bonding portion by suppressing the generation of the above-mentioned residue, and since the reflow process is performed in a formic acid gas atmosphere, the oxide is reduced and removed.
  • the bonding material is, for example, a substrate or the like, and the bonding material is, for example, a semiconductor element such as an LED device.
  • the flux for solder paste the solder paste
  • the method for forming a solder bump using the solder paste and the method for manufacturing a joined body of the present invention, generation of a residue and re-oxidation of the surface of the solder can be suppressed.
  • the flux for solder paste of the present embodiment (hereinafter sometimes referred to simply as flux) is a flux containing a caking agent, a solvent, and a thixotropic agent, and has an acid value of 100 mg KOH / g or less, and the thermogravimetric measurement
  • the decreasing rate at 300 ° C. is 80 mass% or more, the viscosity is 0.5 Pa ⁇ s or more, and the tacking force is 1.0 N or more.
  • the reason for defining the composition of the flux, the acid value, the reduction rate at 300 ° C. in thermogravimetry, the viscosity and the tacking force as described above will be described.
  • the flux comprises a thickener, a solvent, and a thixotropic agent.
  • the flux is composed only of the caking agent, the solvent, and the thixotropic agent.
  • the acid value of the flux is 100 mg KOH / g or less.
  • the acid value of the flux is preferably 50 mg KOH / g or less, more preferably 10 mg KOH / g or less.
  • the flux has a reduction rate of 80% by mass or more at 300 ° C. in thermogravimetry. This is because when the reduction rate at 300 ° C. in thermogravimetry is less than 80% by mass, the amount of residue increases when the solder paste containing the flux is reflowed.
  • the reduction rate at 300 ° C. is preferably 85% by mass or more, and more preferably 90% by mass or more.
  • the upper limit of the amount of reduction is not particularly limited, it is, for example, 99.5% by mass as a numerical value when using a commonly available caking agent.
  • solvents such as alcohols, ketones, esters, ethers, aromatics, hydrocarbons, terpenes and terpenoids are used.
  • solvents such as alcohols, ketones, esters, ethers, aromatics, hydrocarbons, terpenes and terpenoids.
  • thixotropic agents contained in the flux hydrogenated castor oil, hydrogenated castor oil, carnauba wax, amides, hydroxy fatty acids, dibenzylidene sorbitol, bis (p-methylbenzylidene) sorbitols, beeswax, stearic acid amide, hydroxys Thearenic acid ethylene bisamide etc. are used individually or in mixture of these.
  • fatty acids such as caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid and behenic acid, hydroxy fatty acids such as 1,2-hydroxystearic acid, antioxidants, surfactants, if necessary. Amines and the like are added and used.
  • the viscosity of the flux is 0.5 Pa ⁇ s or more. If the viscosity of the flux is less than 0.5 Pa ⁇ s, the viscosity of the flux is too small to form a solder paste, and there is a possibility that the composition can not be applied to a substrate or the like.
  • the viscosity of the flux is preferably 1.0 Pa ⁇ s or more.
  • a viscosity is a viscosity at the time of room temperature (25 degreeC).
  • the upper limit of the viscosity is not particularly limited, but is, for example, 100 Pa ⁇ s from the viewpoint of coatability and the like.
  • the tacking force of the flux is 1.0 N or more.
  • the tacking force of the flux is less than 1.0 N, the adhesive strength is low, and thus, when the solder paste containing the flux is applied to a substrate or the like, the applied solder paste may be detached from the substrate or the like.
  • the tacking force of a flux is 1.2 N or more.
  • the tacking force is a numerical value at room temperature (25 ° C.).
  • the upper limit of the tacking force is not particularly limited, but is, for example, 100 N from the viewpoint of plate removal from a mask.
  • the viscosity improver is desirably a solid or a liquid having a viscosity of 1 Pa ⁇ s or more at normal temperature (25 ° C.). This is because if the viscosity of the adhesive is a liquid having a viscosity of less than 1 Pa ⁇ s at room temperature, the viscosity of the flux is too small to form a solder paste and there is a possibility that the paste can not be applied to a substrate or the like. As described above, since the caking agent has a viscosity of 1 Pa ⁇ s or more at normal temperature, or is solid at normal temperature, the solder paste comprising the flux and the solder powder containing this caking agent has a shape-retaining property .
  • the upper limit of the viscosity is not particularly limited, but is, for example, 400 Pa ⁇ s from the viewpoint of coatability and the like.
  • the viscosity reducing agent at 300 ° C. is 90% by mass or more. This is because most of the flux components are caking agents, and if the reduction rate at 300 ° C. is less than 90 mass% in the thermogravimetric measurement, the reduction rate at 300 ° C. in the thermogravimetric measurement of the flux is 80 It is because it can not be more than%.
  • the tacking force of this thickener is set to 1.1 N or more.
  • the tacking force of the caking agent is less than 1.1 N, the tacking force of the flux can not be 1.0 N or more.
  • the upper limit of the tacking force is not particularly limited, but is, for example, 200 N from the viewpoint of plate removal from a mask.
  • a caking agent contained in the flux one having a low decomposition temperature and having viscosity is preferable.
  • the viscosity improver isobornyl cyclohexanol, isobornyl phenol and derivatives thereof, polybden having a number average molecular weight of 700 or more and 1,500 or less, or the like is used. The reason why the number average molecular weight of polybden is 700 or more and 1,500 or less is because the viscosity is less than 1 Pa ⁇ s when the number average molecular weight is less than 700, the viscosity effect is low, and the printability of the solder paste is reduced.
  • the heat resistance becomes high and it tends to remain as a residue.
  • the caking agent is not composed of the rosins, the dimer acid, and the polybden having a number average molecular weight of more than 1,500
  • the reduction rate at 300 ° C. is 90% by mass in thermogravimetry.
  • the viscosity is secured while suppressing the residue from remaining on the solder bumps.
  • the flux of this embodiment does not contain rosins etc. as a main component as mentioned above, the oxide is reduced and removed to wet the base and the effect of covering the solder bumps and preventing reoxidation is poor. .
  • the functions of such rosins are compensated by formic acid gas described later.
  • the composition of such a flux is, for example, 19% by mass to 60% by mass of the solvent, 30% by mass to 80% by mass of the caking agent, and 1.0% to 10% by mass of the thixotropic agent. If the solvent content is less than 19% by mass, the solder paste does not easily become paste-like, and if the solvent content exceeds 60% by mass, the shape of the solder paste (hereinafter referred to as bump precursor) in a print applied state on the substrate. The retention is poor. If the thixotropic agent is less than 1.0% by mass, the shape retention of the solder paste becomes poor, and if it exceeds 10% by mass, the solder paste becomes too hard.
  • the paste can not be formed or becomes a dry paste, and there is a possibility that the solder paste can not be applied to a substrate or the like.
  • the viscosity exceeds 80% by mass, the viscosity of the solder paste becomes too high or the adhesive strength becomes too high, and the scraping property at the time of printing deteriorates, or when applying by a dispenser or pin The shape at the time of transfer may be deteriorated.
  • the preferable composition of the flux is 35% by mass to 80% by mass of the caking agent, 2% by mass to 6% by mass of the thixotropic agent, and the remaining portion being the solvent.
  • composition of further preferable flux 35 mass% or more and 70 mass% or less of a caking agent, 2.5 mass% or more and 5.5 mass% or less of a thixo agent, and a remainder are solvents. If a large amount of activator is contained in the flux for solder paste, the solder powder and flux react with each other when made into solder paste, and the viscosity change becomes large. Can only save. For this reason, in the present embodiment, the flux for solder paste does not contain an activator.
  • the solder paste is a mixture of the flux and the solder powder, and the content of the flux is set to 30% by volume or more and 90% by volume or less.
  • the content rate of the flux for solder paste is less than 30% by volume, the paste can not be formed or becomes a dry paste, and there is a possibility that the solder paste can not be applied to a substrate or the like by printing.
  • the content of the solder paste flux exceeds 90% by volume, the viscosity of the solder paste becomes too high, or the adhesive strength becomes too high, and the scraping property at the time of printing deteriorates, or The shape at the time of application or at the time of pin transfer may be deteriorated.
  • the flux content is set to 30% by volume or more and 90% by volume or less.
  • the content of the flux is preferably 40% by volume or more and 90% by volume or less.
  • solder powder examples include Sn-Ag-Cu solder powder, Sn-Cu solder powder, Sn-Ag solder powder, Pb-Sn solder powder, Au-Sn solder powder, and Au-Ge solder powder.
  • the average particle diameter of the solder powder is, for example, in the range of 0.1 to 30.0 ⁇ m, which can enhance the paste filling property to the mask opening and the shape retention property of the bump precursor. In order to narrow the bump formation, the average particle diameter of the solder powder is preferably in the range of 0.1 to 10.0 ⁇ m.
  • This formation method includes a printing step of printing a solder paste, and a reflow step of heating the solder paste in a formic acid gas atmosphere.
  • This formation method includes a printing step of printing a solder paste, and a reflow step of heating the solder paste in a formic acid gas atmosphere.
  • details will be described in the order of the printing process and the reflow process.
  • a mask having an opening is disposed on a substrate such as a silicon wafer or a glass epoxy resin substrate, and a solder paste is applied by printing so as to fill the opening with the solder paste.
  • the mask is peeled off from the substrate to form a bump precursor on the substrate.
  • the solder paste is applied by printing, it may be discharged and supplied by a dispenser or the like, or may be pin transferred by a pin transfer device or the like.
  • the caking agent is a solid at room temperature or a liquid having a viscosity of 1 Pa ⁇ s or more, it is possible to ensure the shape retention of the solder paste flux and the solder powder containing the caking agent.
  • the content rate of the flux for solder paste is 30 volume% or more and 90 volume% or less, the solder paste of appropriate viscosity and adhesiveness can be comprised, and the deterioration of the scraping property at the time of printing etc. can be suppressed.
  • the bump precursor formed on the substrate is heated under a formic acid gas atmosphere at a temperature lower than the melting point of the solder powder for 30 seconds to 2 minutes (preheating process). Volatilize the solvent.
  • Each heat process under the formic acid gas atmosphere, to generate a gas was dissolve formic acid to N 2 in the gas by bubbling N 2 at room temperature in 99% formic acid, N 2 to dissolved gases in this formic acid Is carried out by supplying
  • the formic acid concentration of the N 2 gas (formic acid gas) in which the formic acid is dissolved is set to, for example, about 3% by volume.
  • the formic acid gas atmosphere may be generated by placing formic acid in the furnace.
  • the solder powder is heated by heating for 10 seconds to 1 minute (main heat step) at a temperature higher than the melting point of the solder powder, for example, the temperature of the melting point + 30 ° C. of the solder powder (main heating step).
  • formic acid is reacted with a metal oxide such as Sn contained in the solder powder to form a formic acid salt, and then the formic acid salt is reduced by formic acid by being placed at a higher temperature.
  • a metal oxide such as Sn contained in the solder powder
  • the formic acid salt is reduced by formic acid by being placed at a higher temperature.
  • an oxide film such as a solder powder is reduced by the reducing power of formic acid.
  • a substantially hemispherical solder bump is formed by surface tension.
  • the flux for solder paste has a reduction rate at 300 ° C. of 80 mass% or more in thermogravimetry, and among them, the reduction amount of the caking agent at 300 ° C. in thermogravimetry is 90 mass % Or more, when a solder paste containing a flux for solder paste is reflowed, there is also a large amount of volatile component as a flux, so even if a bump precursor is reflowed to form a solder bump, a residue Can be suppressed and the process of cleaning the solder bumps can be omitted.
  • the reducing power of the formic acid gas causes the solder powder and the substrate to be reduced.
  • the oxide film can be reduced to facilitate solder melting.
  • the flux for a solder paste of the present embodiment since generation of a residue is suppressed by using the flux for a solder paste of the present embodiment, it is possible to prevent jumping of the residue at the time of reflow even if the solder powder is a high melting point Au-Sn solder powder. Furthermore, since the acid value of the flux for solder paste is set to 100 mg KOH / g or less, generation of voids in the solder bump can be suppressed, and the solder paste can be stored for a long time (for example, 6 months or more). Storage can be improved.
  • the flux is composed only of the caking agent, the solvent, and the thixotropic agent, but not limited thereto, the acid value is 100 mg KOH / g or less, and the thermogravimetric measurement at 300 ° C. If the reduction rate is in the range of 80% by mass or more, the viscosity is 0.5 Pa ⁇ s or more, and the tacking force is 1.0 N or more, the flux may contain a slight amount of rosins and an activator. .
  • the heating temperature is raised stepwise in two steps by performing the preheating step and the main heating step in the reflow step, but the present invention is not limited to this, and only the main heating step is performed. May be Also, the heating temperature may be raised stepwise in three or more steps.
  • the solder paste of not only this but this invention is arrange
  • Solder pastes were manufactured while changing various conditions, and experiments were conducted on the amount of residue after reflow of the solder bumps obtained from the solder paste, the long-term storability of the solder paste, and the shape retention.
  • the obtained samples of Examples 1 to 9 and Comparative Examples 1 to 6 will be described with reference to Tables 1 and 2.
  • thermogravimetric measurement the rate of decrease at 300 ° C. in the thermogravimetric measurement of each of the flux and the caking agent (hereinafter, referred to as 300 ° C. TG decrease in Table 1) was measured using a general thermogravimetric measurement apparatus.
  • the thermogravimetry flux the flux of 10mg under N 2 atmosphere, heating 10 ° C. / min, by measuring the weight change when the temperature was raised to 300 ° C. from room temperature (25 ° C.), The above reduction rate was determined. The same is true for the thickeners.
  • the flux and viscosity of the caking agent were measured in accordance with JIS Z 8803.
  • a solder paste was manufactured by mixing the solder powder and the flux shown in Table 1 in the proportion shown in Table 1.
  • the flux is prepared by mixing a thickener, a thixo agent, a solvent and an activator, and the thickener, thixo agent, solvent and activator are as described in Table 1, and the thixo agent is 5% by mass. The remainder was solvent. Evaluation about the presence or absence of the residue after reflow, the long-term storability of a solder paste, and shape retention was performed by the following method.
  • the heating under formic acid gas atmosphere, room temperature to generate a gas was dissolve formic acid to N 2 in the gas by bubbling N 2 in, by supplying N 2 to dissolved gases in this formic acid in a furnace I did.
  • the formic acid concentration of the N 2 gas (formic acid gas) in which this formic acid was dissolved was about 3% by volume.
  • the reflowed bump precursor solder bump
  • SEM electron microscope
  • solder bump precursors were applied onto the evaluation substrate with a mask having a pitch of 200 ⁇ m, an opening diameter of 120 ⁇ m, and a thickness of 25 ⁇ m to form 100 bump precursors.
  • the evaluation substrate on which 100 bump precursors have been formed is observed visually or with an optical microscope, and the number of missing portions is 5 or less, the number of bridges due to printing sag is 5 or less, of the 100 bumps. The case where the number of chippings was five or less was judged as good, and the case where any of the missing, the bridge and the chiping occurred at more than five positions was judged as defective.
  • thermogravimetric measurement of the flux As can be seen from Tables 1 and 2, in Comparative Examples 1, 3 and 6, since the decrease amount at 300 ° C. in the thermogravimetric measurement of the flux is as low as 60 mass% or less, the area where the residue after reflow is generated is It exceeded 30% of the application area of the solder paste, and there were many residues after reflow. On the other hand, in Examples 1 to 9, since the reduction rate at 300 ° C. in the thermogravimetric measurement of the flux was 80 mass% or more, there were few residues after reflow. Moreover, since the reduction rate in 300 degreeC in the thermogravimetric measurement of flux was 80 mass% or more also in Comparative example 2, 4 and 5, the residue after reflow was few. For this reason, in thermogravimetric measurement of the flux, it was found that it is an effective range that the reduction amounts at 300 ° C. are all 80 mass% or more.
  • Comparative Examples 1, 2 and 5 were inferior in long-term storage property because the acid value of the flux was as high as 200 to 1500 mg KOH / g.
  • the acid value of the flux was 100 mg KOH / g or less, the long-term storability of the solder paste was excellent.
  • the acid value of the flux was below the detection limit also in Comparative Examples 3, 4 and 6, the long-term storability of the solder paste was excellent. For this reason, it was found that it is an effective range that the acid value of the flux is 100 mg KOH / g or less.
  • Example 2 although the flux contained 0.1 mass% activator, since the acid value of a flux is 100 mgKOH / g or less, it was excellent in long-term storage property. On the other hand, in Comparative Example 2, since the flux contains 0.2% by mass of the activator, the acid value of the flux is as high as 200 mg KOH / g, and the long-term storage stability is inferior. For this reason, it was found that if the acid value of the flux is within the above range, it may contain 0.1% by mass or less of the activator.
  • Comparative Example 5 since the flux contains 40% by mass of the polymerized rosin, the acid value of the flux is as high as 800 mg KOH / g, and the long-term storage stability is inferior. On the other hand, in Example 8, although the flux contained 5% by mass of polymerized rosin, it was excellent in long-term storage performance. Further, in Comparative Example 6, since the flux contains a rosin ester of 40% by mass, the reduction amount at 300 ° C. in thermogravimetric measurement is as low as 60% by mass or less, and the residue after reflow is large. On the other hand, in Example 9, although the flux contained 10% by mass of rosin ester, the residual after reflow was small. From these facts, it was found that as long as the acid value of the flux and the reduction amount at 300 ° C. in thermogravimetric measurement fall within the above range, it may contain 10% by mass or less of rosins.
  • the reliability of bonding of the electronic component to the substrate can be efficiently improved.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Electric Connection Of Electric Components To Printed Circuits (AREA)

Abstract

This solder paste flux comprises a thickening agent, a solvent, and a thixotropic agent, and that has an acid value of at most 100 mgKOH/g, exhibits a mass reduction rate of at least 80 mass% at 300°C by thermogravimetric measurement, and has a viscosity of at least 0.5 Pa·s and a tacking force of at least 1.0 N.

Description

はんだペースト用フラックス、はんだペースト、はんだペーストを用いたはんだバンプの形成方法及び接合体の製造方法Flux for solder paste, solder paste, method of forming solder bumps using solder paste, and method of manufacturing joined body
　本発明は、電子部品を基板に接合する際等に用いられるはんだを得ることができるはんだペースト用フラックス、はんだペースト、はんだペーストを用いたはんだバンプの形成方法及び接合体の製造方法に関する。
　本願は、２０１７年７月２８日に日本に出願された特願２０１７－１４７０８４号及び２０１８年７月１７日に日本に出願された特願２０１８－１３３８７２号について優先権を主張し、その内容をここに援用する。 The present invention relates to a flux for solder paste, a solder paste, a method of forming solder bumps using the solder paste, and a method of manufacturing a joined body, which can obtain a solder used when bonding an electronic component to a substrate.
Priority is claimed on Japanese Patent Application Nos. 2017-147084 filed on July 28, 2017 and Japanese Patent Application No. 2018-133872 filed on July 17, 2018, the contents of which are incorporated herein by reference. I will use it here.
　従来、はんだ付けには、ロジン、溶剤、チクソ剤及び活性剤を含むフラックスとはんだ粉末とにより構成されるはんだペーストが用いられる。このようなはんだペーストを用いてはんだバンプを形成する場合、はんだペーストを基板の上に塗布してリフロー処理すると、はんだの上面にロジン等に基づく残渣が残ることから、この残渣を薬品等により洗浄する必要があり、煩雑である。
　このような残渣を洗浄する手間を省くため、はんだ付け後に残渣の発生しないフラックス、及びこのフラックスを含有するはんだペーストが知られている（特許文献１参照）。
　この特許文献１に記載のフラックスは、ギ酸アンモニウムと、常温で液体であり、大気圧における沸点が１５０℃以上の脂肪族多価アルコールと、を含有しているため、還元性を有し、効率良く酸化被膜を還元することで、基板等に発生した酸化被膜を除去している。この特許文献１の構成では、基板に電子部品等をはんだ付けした後のフラックスの残渣が抑制される。 Conventionally, a solder paste composed of a solder powder and a flux containing rosin, a solvent, a thixotropic agent, and an activator is used for soldering. When forming a solder bump using such a solder paste, if a solder paste is applied on a substrate and reflowed, a residue based on rosin etc. remains on the upper surface of the solder, so this residue is cleaned with chemicals etc. Need to be complicated.
In order to save time and effort for cleaning such a residue, a flux free of residue after soldering and a solder paste containing the flux are known (see Patent Document 1).
Since the flux described in Patent Document 1 contains ammonium formate and an aliphatic polyhydric alcohol which is liquid at normal temperature and has a boiling point of 150 ° C. or more at atmospheric pressure, it has reducibility and is efficient. By reducing the oxide film well, the oxide film generated on the substrate etc. is removed. In the configuration of Patent Document 1, the residue of the flux after soldering the electronic component and the like to the substrate is suppressed.
　ところで、特許文献１に記載のフラックス及び該フラックスを含有するはんだペーストは、低温で分解されるため、はんだ表面がフラックスにより被覆されずに露出した状態となる。このため、はんだの表面が再酸化されるおそれがある。
　これに対し、はんだの表面の再酸化を抑制できるはんだバンプの形成方法が提案されている（特許文献２参照）。 By the way, since the flux described in Patent Document 1 and the solder paste containing the flux are decomposed at a low temperature, the solder surface is exposed without being covered by the flux. Therefore, the surface of the solder may be reoxidized.
On the other hand, the formation method of the solder bump which can suppress the reoxidation of the surface of a solder is proposed (refer patent document 2).
　この特許文献２に記載のはんだバンプの形成方法は、開口部を有するマスクを基板上に配置し、この開口部内にフラックスとはんだ粉末とを含むはんだペーストを充填するようにはんだペーストを印刷し、マスクを剥離した後、基板上のバンプ前駆体をリフロー処理してはんだバンプを形成する方法であって、フラックスは、ロジン、溶剤及びチクソ剤を含有し、フラックスの酸価値が１００ｍｇＫＯＨ／ｇ以下であって、フラックスのハロゲン含有量が０．０３質量％以下であり、リフロー処理をギ酸ガス雰囲気下及び／又はギ酸が熱により分解されたガスの雰囲気下で行う構成とされている。
　このはんだバンプの形成方法では、リフロー処理をギ酸ガス雰囲気下及び／又はギ酸が熱により分解されたガスの雰囲気下で行うことにより、はんだ粉末等の酸化被膜を還元してはんだ溶融を円滑にしている。 In the method of forming a solder bump described in Patent Document 2, a mask having an opening is disposed on a substrate, and a solder paste is printed so that a solder paste containing flux and solder powder is filled in the opening. A method of forming a solder bump by reflowing a bump precursor on a substrate after peeling off a mask, wherein the flux contains rosin, a solvent and a thixotropic agent, and the acid value of the flux is 100 mg KOH / g or less The halogen content of the flux is 0.03% by mass or less, and the reflow process is performed under a formic acid gas atmosphere and / or under an atmosphere of a gas in which formic acid is thermally decomposed.
In this method for forming solder bumps, the reflow process is performed in a formic acid gas atmosphere and / or in an atmosphere of a gas in which formic acid is thermally decomposed, thereby reducing an oxide film such as solder powder to smooth solder melting. There is.
日本国特開２０１１－８３８０９号公報（Ａ）JP JP 2011-83809 A (A) 日本国特開２０１６－７８０９５号公報（Ａ）Japanese Patent Application Laid-Open No. 2016-78095 (A)
　ところで、特許文献２に記載のはんだバンプの形成方法では、ロジンを主成分とするフラックスを用いるため、この形成方法に用いられるフラックスを含むはんだペーストがリフローされると、ロジンに基づく残渣が発生することから、はんだを洗浄する必要がある。また、はんだを洗浄しても、残渣を完全に取り除くことができない場合があり、この場合、電子部品と基板との接合性が低下するおそれがある。 By the way, in the method of forming a solder bump described in Patent Document 2, since a flux containing rosin as a main component is used, when a solder paste containing the flux used in this forming method is reflowed, a residue based on rosin is generated. Therefore, it is necessary to clean the solder. In addition, even if the solder is washed, the residue may not be completely removed, and in this case, the bonding between the electronic component and the substrate may be deteriorated.
　本発明は、このような事情に鑑みてなされたもので、残渣の発生を抑制できるはんだを得ることができるはんだペースト用フラックス、はんだペースト、はんだペーストを用いたはんだバンプの形成方法及び接合体の製造方法を提供することを目的とする。 The present invention has been made in view of such circumstances, and it is possible to obtain a solder capable of suppressing generation of a residue, a flux for solder paste, a solder paste, a method of forming a solder bump using the solder paste, and a bonding body The purpose is to provide a manufacturing method.
　本発明の一態様のはんだペースト用フラックス（以下、「本発明のはんだペースト用フラックス」と称する）は、粘凋剤、溶剤、及びチクソ剤を含むはんだペースト用フラックスであって、酸価値が１００ｍｇＫＯＨ／ｇ以下であり、熱重量測定において３００℃での減少率が８０質量％以上であり、粘度が０．５Ｐａ・ｓ以上であり、かつ、タッキング力が１．０Ｎ以上である。
　なお、タッキング力とは、はんだ用フラックスを基板等に塗布した際の基板に対する粘着強度を意味し、ＪＩＳＺ３２８４に基づいて測定される。 The flux for solder paste according to one embodiment of the present invention (hereinafter referred to as “flux for solder paste of the present invention”) is a flux for solder paste containing a caking agent, a solvent, and a thixo agent, and has an acid value of 100 mg KOH / G or less, the reduction rate at 300 ° C. in thermogravimetry is 80 mass% or more, the viscosity is 0.5 Pa · s or more, and the tacking force is 1.0 N or more.
In addition, tacking force means the adhesive strength with respect to the board | substrate at the time of apply | coating the flux for solders to a board | substrate etc., and is measured based on JISZ3284.
　本発明では、はんだペースト用フラックスが熱重量測定において３００℃での減少率が８０質量％以上であるため、はんだペースト用フラックスを含むはんだペーストがリフローされた際に、フラックスとして揮発分が多いため、上記はんだペースト用フラックスを含むはんだペーストがリフローされてはんだバンプが形成された場合であっても、残渣が発生することを抑制できる。
　また、はんだペースト用フラックスの粘度が０．５Ｐａ・ｓ未満であると、このフラックスの粘度が小さすぎて、はんだペーストを構成できず、基板などに塗布できないおそれがある。さらに、はんだペースト用フラックスのタッキング力が１．０Ｎ未満であると、粘着強度が低いため、このフラックスを含むはんだペーストを基板などに塗布した際に、塗布したはんだペーストが基板などからずれ落ちたりするおそれがある。これに対し、本発明では、フラックスの粘度が０．５Ｐａ・ｓ以上であり、かつ、タッキング力が１．０Ｎ以上とされているので、はんだペースト用フラックス及びはんだ粉末からなるはんだペーストの形状保持性を確保できる。 In the present invention, since the reduction rate at 300 ° C. in the thermogravimetric measurement of the flux for solder paste is 80 mass% or more, when the solder paste containing the flux for solder paste is reflowed, the volatile content is large as flux Even when the solder paste containing the flux for solder paste is reflowed to form a solder bump, generation of a residue can be suppressed.
If the viscosity of the flux for solder paste is less than 0.5 Pa · s, the viscosity of the flux is too small to form a solder paste, and there is a possibility that the paste can not be applied to a substrate or the like. Furthermore, when the tacking force of the flux for solder paste is less than 1.0 N, the adhesive strength is low, so when the solder paste containing this flux is applied to a substrate or the like, the applied solder paste may slip off from the substrate or the like There is a risk of On the other hand, in the present invention, since the viscosity of the flux is 0.5 Pa · s or more and the tacking force is 1.0 N or more, the shape retention of the solder paste comprising the flux for solder paste and the solder powder I can secure the sex.
　また、はんだペースト用フラックスの酸価値を１００ｍｇＫＯＨ／ｇ以下に設定したことにより、僅かに残り得るフラックス残渣と周囲の金属部分、例えば配線の銅等、との反応が抑制され、腐食を押さえることができ、接合体の長期信頼性を確保できる。加えて、はんだペーストとしたときのはんだ粉末とフラックスとが反応することが抑制され、はんだペーストとしての粘度変化が少なくなるので、通常は冷蔵保管が必要なはんだペーストを室温で長期間（例えば、６か月以上）保存でき、長期保管性を向上できる。
　また、この酸価値が１００ｍｇＫＯＨ／ｇを超えると、はんだペースト用フラックスとはんだ粉末の酸化物との還元反応で生じる還元水の発生が多くなり、はんだバンプ内のボイドが多くなるため、上記酸価値を１００ｍｇＫＯＨ／ｇ以下に設定している。
　なお、本発明のはんだペースト用フラックスには、通常のフラックスに含まれるロジン類や活性剤を含まないことが好ましいが、上記熱重量測定及び酸価値の要件を満たす範囲であればわずかに含有されていてもよい。 Moreover, by setting the acid value of the flux for solder paste to 100 mg KOH / g or less, the reaction between the flux residue that may be slightly left and the surrounding metal portion, such as copper of the wiring, can be suppressed to suppress corrosion. It is possible to secure the long-term reliability of the assembly. In addition, since the reaction between the solder powder and the flux when forming the solder paste is suppressed, and the viscosity change as the solder paste is reduced, the solder paste which normally needs to be stored under refrigeration for a long time at room temperature (for example, Can be stored for more than 6 months, and can improve long-term storage performance.
In addition, when the acid value exceeds 100 mg KOH / g, the generation of reduced water generated by the reduction reaction between the solder paste flux and the oxide of the solder powder increases, and the number of voids in the solder bump increases. Is set to 100 mg KOH / g or less.
Although it is preferable that the flux for solder paste of the present invention does not contain rosins and activators contained in ordinary flux, it is slightly contained in the range that satisfies the requirements of the above-mentioned thermogravimetry and acid value. It may be
　本発明のはんだペースト用フラックスの好ましい態様としては、ロジン類の含有量が１０質量％以下であるとよい。
　はんだペースト用フラックス内にロジン類が含まれていても、その量が１０質量％以下であれば、はんだペースト用フラックスの酸価値を１００ｍｇＫＯＨ／ｇ以下にできる。すなわち、はんだペースト用フラックスは、ロジン類を１０質量％以下の範囲内であれば、含むことを妨げない。 As a preferable aspect of the flux for solder pastes of this invention, it is good for content of rosins to be 10 mass% or less.
Even if the flux for solder paste contains rosins, the acid value of the flux for solder paste can be 100 mg KOH / g or less if the amount is 10 mass% or less. That is, the flux for solder paste does not prevent inclusion of rosins if it is in the range of 10% by mass or less.
　本発明の他態様のはんだペースト（以下、「本発明のはんだペースト」と称する）は、上記はんだペースト用フラックスと、はんだ粉末とを混合してなる。
　本発明のはんだペーストは、上記はんだペースト用フラックスを含んでいるので、はんだペーストがリフローされた場合であっても、残渣の発生を抑制でき、残渣が残ることにより生じる接合性の低下を抑制できる。 The solder paste of the other aspect of the present invention (hereinafter referred to as "the solder paste of the present invention") is formed by mixing the flux for solder paste and a solder powder.
Since the solder paste of the present invention contains the above-mentioned flux for solder paste, even when the solder paste is reflowed, the generation of residues can be suppressed, and the decrease in bonding caused by the residues remaining can be suppressed. .
　本発明のはんだペーストの好ましい態様としては、前記はんだペースト用フラックスの含有率が３０体積％以上９０体積％以下であるとよい。
　はんだペースト用フラックスの含有率が３０体積％未満の場合、ペーストを構成できないか、若しくは、乾いたペーストとなり、はんだペーストを基板などに塗布できないおそれがある。一方、はんだペースト用フラックスの含有率が９０体積％を超えていると、はんだペーストの粘度が低くなりすぎて塗布性能が悪化したり、フラックスとはんだ粉末が分離しやすくなったりするおそれがある。
　これに対し、上記態様では、はんだペースト用フラックスの含有率が３０体積％以上９０体積％以下であることから、適切な粘度のはんだペーストを構成でき、塗布性能の悪化や、フラックスとはんだ粉末との分離を抑制できる。 As a preferable aspect of the solder paste of the present invention, the content of the flux for solder paste is preferably 30% by volume or more and 90% by volume or less.
If the content of the solder paste flux is less than 30% by volume, the paste can not be formed or becomes a dry paste, and there is a possibility that the solder paste can not be applied to a substrate or the like. On the other hand, if the content of the flux for solder paste exceeds 90% by volume, the viscosity of the solder paste becomes too low, which may deteriorate the coating performance or the flux and the solder powder may be easily separated.
On the other hand, in the above aspect, since the content of the flux for solder paste is 30% by volume or more and 90% by volume or less, a solder paste having an appropriate viscosity can be formed, and the coating performance is deteriorated. Separation of the
　本発明のはんだペーストの好ましい態様としては、前記はんだ粉末は、Ｓｎ－Ａｇ－Ｃｕはんだ粉末、Ｓｎ－Ｃｕはんだ粉末、Ｓｎ－Ａｇはんだ粉末、Ｐｂ－Ｓｎはんだ粉末、Ａｕ－Ｓｎはんだ粉末、Ａｕ－Ｇｅはんだ粉末、Ａｕ－Ｓｉはんだ粉末のいずれかであるとよい。
　上記態様によれば、上記各種粉末のいずれかをはんだ粉末として使用できる。特に、はんだ粉末がＡｕ－Ｓｎはんだ粉末の場合、Ａｕ－Ｓｎはんだ粉末を含むはんだペーストは、高融点のはんだペーストであるため、リフロー時に残渣の飛び跳ねが起こりやすいが、上記はんだペースト用フラックスを使用することで残渣の発生が抑制されるので、リフロー時の残渣の飛び跳ねを防止できる。 In a preferred embodiment of the solder paste according to the present invention, the solder powder is Sn—Ag—Cu solder powder, Sn—Cu solder powder, Sn—Ag solder powder, Pb—Sn solder powder, Au—Sn solder powder, Au— It may be either Ge solder powder or Au-Si solder powder.
According to the above aspect, any of the above-mentioned various powders can be used as the solder powder. In particular, when the solder powder is Au-Sn solder powder, the solder paste containing Au-Sn solder powder is a solder paste with a high melting point, and therefore the residue is likely to jump during reflow, but the flux for solder paste is used Since the generation of the residue is suppressed by doing this, it is possible to prevent the jump of the residue at the time of reflow.
　本発明の他態様のはんだペーストを用いたはんだバンプの形成方法（以下、「本発明のはんだペーストを用いたはんだバンプの形成方法」と称する）は、開口部を有するマスクを基板上に配置し、前記開口部内に上記はんだペーストを充填するように前記はんだペーストを印刷し、前記マスクを剥離した後前記基板上のバンプ前駆体をギ酸ガス雰囲気下でリフロー処理してはんだバンプを形成する。
　このような構成によれば、上記残渣が発生することを抑制することで、はんだバンプの洗浄工程を省くことができる他、ギ酸ガス雰囲気下でリフロー処理がなされるので、酸化物を還元除去するロジン類等が含まれていなくても、基板上の酸化被膜及びはんだの表面の酸化被膜を還元してはんだ溶融を円滑にできる。 In a method of forming a solder bump using a solder paste according to another aspect of the present invention (hereinafter referred to as “a method for forming a solder bump using a solder paste according to the present invention”), a mask having an opening is arranged on a substrate The solder paste is printed so as to fill the solder paste in the opening, and after peeling off the mask, the bump precursor on the substrate is subjected to a reflow process in a formic acid gas atmosphere to form a solder bump.
According to such a configuration, the step of cleaning the solder bumps can be omitted by suppressing the generation of the above-mentioned residue, and the reflow process is performed in a formic acid gas atmosphere, so the oxide is reduced and removed. Even if rosins and the like are not contained, the oxide film on the substrate and the oxide film on the surface of the solder can be reduced to facilitate solder melting.
　本発明の他態様のはんだペーストを用いた接合体の製造方法（以下、「本発明のはんだペーストを用いた接合体の製造方法」と称する）は、はんだペーストを用いた接合体の製造方法であって、接合物と被接合物との間に上記はんだペーストを配置し、ギ酸ガス雰囲気下で加熱することによって前記接合物と前記被接合物とをはんだ接合する。
　このような構成によれば、上記残渣が発生することを抑制することで、接合部の洗浄工程を省くことができる他、ギ酸ガス雰囲気下でリフロー処理がなされるので、酸化物を還元除去するロジン類等が含まれていなくても、接合物及び被接合物上の酸化被膜及びはんだの表面の酸化被膜を還元してはんだ溶融を円滑にでき、接合物及び被接合物をより強固に接合できる。
　なお、はんだペーストを配置する方法としては、特に限定されず、例えば、印刷法やディスペンサによる塗布、ピン転写等で配置することが出来る。また、接合物しては、例えば基板等であり、被接合物としては、例えば、ＬＥＤ素子等の半導体素子等である。 The method for producing a joined body using the solder paste according to another aspect of the present invention (hereinafter referred to as “the method for producing a joined body using the solder paste according to the present invention”) is a method for producing a joined body using a solder paste The solder paste is placed between a joint and a workpiece, and the joint and the workpiece are solder-bonded by heating in a formic acid gas atmosphere.
According to such a configuration, it is possible to omit the step of cleaning the bonding portion by suppressing the generation of the above-mentioned residue, and since the reflow process is performed in a formic acid gas atmosphere, the oxide is reduced and removed. Even if it does not contain rosins, it is possible to reduce the oxide film on the surface of the joint and the object to be bonded and the oxide layer on the surface of the solder to smooth solder melting and to bond the joint and the object more firmly. it can.
In addition, it does not specifically limit as a method to arrange | position a solder paste, For example, application by a printing method, a dispenser, it can arrange | position by pin transfer etc. The bonding material is, for example, a substrate or the like, and the bonding material is, for example, a semiconductor element such as an LED device.
　本発明のはんだペースト用フラックス、はんだペースト、はんだペーストを用いたはんだバンプの形成方法及び接合体の製造方法では、残渣の発生及びはんだの表面の再酸化を抑制できる。 According to the flux for solder paste, the solder paste, the method for forming a solder bump using the solder paste, and the method for manufacturing a joined body of the present invention, generation of a residue and re-oxidation of the surface of the solder can be suppressed.
　以下、本発明に係るはんだペースト用フラックス、はんだペースト及びはんだペーストを用いたはんだバンプの形成方法について説明する。
　本実施形態のはんだペースト用フラックス（以下、単にフラックスという場合がある）は、粘凋剤、溶剤、及びチクソ剤を含むフラックスであって、酸価値が１００ｍｇＫＯＨ／ｇ以下であり、熱重量測定において３００℃での減少率が８０質量％以上であり、粘度が０．５Ｐａ・ｓ以上であり、かつ、タッキング力が１．０Ｎ以上である。
　以下に、フラックスの構成、酸価値、熱重量測定における３００℃での減少率、粘度及びタッキング力を、上述のように規定した理由について説明する。 Hereinafter, a method for forming a solder bump using the flux for solder paste, the solder paste, and the solder paste according to the present invention will be described.
The flux for solder paste of the present embodiment (hereinafter sometimes referred to simply as flux) is a flux containing a caking agent, a solvent, and a thixotropic agent, and has an acid value of 100 mg KOH / g or less, and the thermogravimetric measurement The decreasing rate at 300 ° C. is 80 mass% or more, the viscosity is 0.5 Pa · s or more, and the tacking force is 1.0 N or more.
Hereinafter, the reason for defining the composition of the flux, the acid value, the reduction rate at 300 ° C. in thermogravimetry, the viscosity and the tacking force as described above will be described.
　［フラックスの構成］
　フラックスは、粘凋剤、溶剤、及びチクソ剤を含んで構成される。なお、本実施形態では、フラックスは、粘凋剤、溶剤、及びチクソ剤のみから構成される。
　フラックスの酸価値は、１００ｍｇＫＯＨ／ｇ以下とされている。この酸価値を１００ｍｇＫＯＨ／ｇ以下に設定したことにより、はんだペーストとしたときのはんだ粉末とフラックスとが反応することが抑制され、はんだペーストとしての粘度変化を少なくするためである。また、酸価値が上記値を超えると、フラックスとはんだ粉末の酸化物との還元反応で生じる還元水の発生が多くなり、形成されたはんだバンプ内のボイドが多くなるためである。なお、フラックスの酸価値は、５０ｍｇＫＯＨ／ｇ以下であることが好ましく、１０ｍｇＫＯＨ／ｇ以下であることがより好ましい。酸価値の下限に特に制限はなく、測定の検出下限値以下であってもよいが、例えば、０．０１ｍｇＫＯＨ／ｇである。
　さらに、フラックスは、熱重量測定において３００℃での減少率が８０質量％以上である。これは熱重量測定において３００℃での減少率が８０質量％未満であると、フラックスを含むはんだペーストがリフローされた際に残渣の量が多くなるからである。なお、フラックスは、熱重量測定において３００℃での減少率が８５質量％以上であることが好ましく、９０質量％以上であることがより好ましい。減少量の上限に特に制限はないが、一般的に利用可能な粘凋剤を用いた場合の数値として、例えば、９９．５質量％である。 [Flux composition]
The flux comprises a thickener, a solvent, and a thixotropic agent. In the present embodiment, the flux is composed only of the caking agent, the solvent, and the thixotropic agent.
The acid value of the flux is 100 mg KOH / g or less. By setting the acid value to 100 mg KOH / g or less, the reaction between the solder powder and the flux when used as a solder paste is suppressed, and the change in viscosity as the solder paste is reduced. In addition, when the acid value exceeds the above value, the generation of reduced water generated by the reduction reaction between the flux and the oxide of the solder powder increases, and the voids in the formed solder bumps increase. The acid value of the flux is preferably 50 mg KOH / g or less, more preferably 10 mg KOH / g or less. There is no restriction | limiting in particular in the minimum of an acid value, Although it may be below the detection lower limit of a measurement, it is 0.01 mgKOH / g, for example.
Further, the flux has a reduction rate of 80% by mass or more at 300 ° C. in thermogravimetry. This is because when the reduction rate at 300 ° C. in thermogravimetry is less than 80% by mass, the amount of residue increases when the solder paste containing the flux is reflowed. In the thermogravimetric measurement, the reduction rate at 300 ° C. is preferably 85% by mass or more, and more preferably 90% by mass or more. Although the upper limit of the amount of reduction is not particularly limited, it is, for example, 99.5% by mass as a numerical value when using a commonly available caking agent.
　フラックスに含まれる溶剤としては、アルコール、ケトン、エステル、エーテル、芳香族系、炭化水素類、テルペン系及びテルペノイド系等の溶剤が用いられる。具体的には、ベンジルアルコール、エタノール、エチルアルコール、イソプロピルアルコール、ブタノール、ジエチレングリコール、エチレングリコール、エチルセロソルブ、ブチルセロソルブ、ブチルカルビトール 、イソプロピルアルコール、酢酸エチル、酢酸ブチル、安息香酸ブチル、アジピン酸ジエチル、ドデカン、テトラデセン、α－テルピネオール、２－メチル２，４－ペンタンジオール、２－エチル－１，３－ヘキサンジオール、トルエン、キシレン、プロピレングリコールモノフェニルエーテル、ジエチレングリコールモノヘキシルエーテル、エチレングリコールモノブチルエーテル、ジエチレングリコールモノブチルエーテル、ジイソブチルアジペート、へキシレングリコール、シクロヘキサンジメタノール、２－ターピニルオキシエタノール、２－ジヒドロターピニルオキシエタノール、シトラール、リナロール、リモネン、カルバクロール、ピネン、ファルネセンなどが単独又はこれらを混合して用いられる。 As the solvent contained in the flux, solvents such as alcohols, ketones, esters, ethers, aromatics, hydrocarbons, terpenes and terpenoids are used. Specifically, benzyl alcohol, ethanol, ethyl alcohol, isopropyl alcohol, butanol, diethylene glycol, ethylene glycol, ethyl cellosolve, butyl cellosolve, butyl carbitol, isopropyl alcohol, ethyl acetate, butyl acetate, butyl benzoate, diethyl adipate, dodecane , Tetradecene, α-terpineol, 2-methyl 2,4-pentanediol, 2-ethyl-1,3-hexanediol, toluene, xylene, propylene glycol monophenyl ether, diethylene glycol monohexyl ether, ethylene glycol monobutyl ether, diethylene glycol mono Butyl ether, diisobutyl adipate, hexylene glycol, cyclohexane dimethanol, 2-terpiny Roxyethanol, 2-dihydroterpinyloxyethanol, citral, linalool, limonene, carvacrol, pinene, farnesene and the like may be used alone or in combination.
　また、フラックスに含まれるチクソ剤としては、硬化ひまし油、水素添加ひまし油、カルナバワックス、アミド類、ヒドロキシ脂肪酸類、ジベンジリデンソルビトール、ビス（ｐ－メチルベンジリデン）ソルビトール類、蜜蝋、ステアリン酸アミド、ヒドロキシス テアリン酸エチレンビスアミド等が単独又はこれらを混合して用いられる。更にこれらに必要に応じてカプリル酸、ラウリン酸、ミリスチン酸、パルミチン酸、ステアリン酸、ベヘニン酸のような脂肪酸、１，２－ヒドロキシステアリン酸のようなヒドロキシ脂肪酸、酸化防止剤、界面活性剤、アミン類等を添加して用いられる。 Moreover, as thixotropic agents contained in the flux, hydrogenated castor oil, hydrogenated castor oil, carnauba wax, amides, hydroxy fatty acids, dibenzylidene sorbitol, bis (p-methylbenzylidene) sorbitols, beeswax, stearic acid amide, hydroxys Thearenic acid ethylene bisamide etc. are used individually or in mixture of these. Furthermore, if necessary, fatty acids such as caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid and behenic acid, hydroxy fatty acids such as 1,2-hydroxystearic acid, antioxidants, surfactants, if necessary. Amines and the like are added and used.
　フラックスの粘度は、０．５Ｐａ・ｓ以上である。フラックスの粘度が０．５Ｐａ・ｓ未満であると、このフラックスの粘度が小さすぎて、はんだペーストを構成できず、基板などに塗布できないおそれがある。なお、フラックスの粘度は、１．０Ｐａ・ｓ以上であることが好ましい。なお、粘度は室温（２５℃）の時の粘度である。粘度の上限に特に制限はないが、塗布性などの観点から、例えば、１００Ｐａ・ｓである。
　また、フラックスのタッキング力は、１．０Ｎ以上である。フラックスのタッキング力が１．０Ｎ未満であると、粘着強度が低いため、このフラックスを含むはんだペーストを基板などに塗布した際に、塗布したはんだペーストが基板などからずれ落ちたりするおそれがある。なお、フラックスのタッキング力は、１．２Ｎ以上であることが好ましい。なお、タッキング力は室温（２５℃）の時の数値である。タッキング力の上限に特に制限はないが、マスクからの版抜け性などの観点から、例えば、１００Ｎである。 The viscosity of the flux is 0.5 Pa · s or more. If the viscosity of the flux is less than 0.5 Pa · s, the viscosity of the flux is too small to form a solder paste, and there is a possibility that the composition can not be applied to a substrate or the like. The viscosity of the flux is preferably 1.0 Pa · s or more. In addition, a viscosity is a viscosity at the time of room temperature (25 degreeC). The upper limit of the viscosity is not particularly limited, but is, for example, 100 Pa · s from the viewpoint of coatability and the like.
Moreover, the tacking force of the flux is 1.0 N or more. When the tacking force of the flux is less than 1.0 N, the adhesive strength is low, and thus, when the solder paste containing the flux is applied to a substrate or the like, the applied solder paste may be detached from the substrate or the like. In addition, it is preferable that the tacking force of a flux is 1.2 N or more. The tacking force is a numerical value at room temperature (25 ° C.). The upper limit of the tacking force is not particularly limited, but is, for example, 100 N from the viewpoint of plate removal from a mask.
［粘凋剤の構成］
　粘凋剤は、常温（２５℃）で固体又は粘度が１Ｐａ・ｓ以上の液体であることが望ましい。これは、粘凋剤が常温で粘度が１Ｐａ・ｓ未満の液体であると、フラックスの粘度が小さすぎて、はんだペーストを構成できず、基板等に塗布できないおそれがあるからである。このように粘凋剤が常温で１Ｐａ・ｓ以上の粘度を有している、若しくは常温で固体であるため、この粘凋剤を含むフラックス及びはんだ粉末からなるはんだペーストは、形状保持性を有する。粘度の上限に特に制限はないが、塗布性などの観点から、例えば、４００Ｐａ・ｓである。
　また、粘凋剤は、熱重量測定において、３００℃での減少量が９０質量％以上である。これは、フラックス成分のうちの多くが粘凋剤であるため、熱重量測定において３００℃での減少率が９０質量％未満であると、フラックスの熱重量測定において３００℃での減少率を８０％以上にできないからである。減少率の上限に特に制限はなく、１００質量％減少する粘凋剤を用いることも可能である。
　この粘凋剤のタッキング力は、１．１Ｎ以上に設定されている。上述したように、フラックス成分のうちの多く粘凋剤であるため、粘凋剤のタッキング力が１．１Ｎ未満であると、フラックスのタッキング力を１．０Ｎ以上にできないからである。タッキング力の上限に特に制限はないが、マスクからの版抜け性などの観点から、例えば、２００Ｎである。 [Composition of adhesive]
The viscosity improver is desirably a solid or a liquid having a viscosity of 1 Pa · s or more at normal temperature (25 ° C.). This is because if the viscosity of the adhesive is a liquid having a viscosity of less than 1 Pa · s at room temperature, the viscosity of the flux is too small to form a solder paste and there is a possibility that the paste can not be applied to a substrate or the like. As described above, since the caking agent has a viscosity of 1 Pa · s or more at normal temperature, or is solid at normal temperature, the solder paste comprising the flux and the solder powder containing this caking agent has a shape-retaining property . The upper limit of the viscosity is not particularly limited, but is, for example, 400 Pa · s from the viewpoint of coatability and the like.
In the thermogravimetric measurement, the viscosity reducing agent at 300 ° C. is 90% by mass or more. This is because most of the flux components are caking agents, and if the reduction rate at 300 ° C. is less than 90 mass% in the thermogravimetric measurement, the reduction rate at 300 ° C. in the thermogravimetric measurement of the flux is 80 It is because it can not be more than%. There is no particular limitation on the upper limit of the reduction rate, and it is also possible to use a viscosity reducing agent that reduces 100% by mass.
The tacking force of this thickener is set to 1.1 N or more. As described above, since many of the flux components are caking agents, if the tacking force of the caking agent is less than 1.1 N, the tacking force of the flux can not be 1.0 N or more. The upper limit of the tacking force is not particularly limited, but is, for example, 200 N from the viewpoint of plate removal from a mask.
　フラックスに含まれる粘凋剤としては、分解温度が低く、粘凋性を有するものが好ましい。例えば、粘凋剤としては、イソボルニルシクロヘキサノール、イソボルニルフェノール及びこれらの誘導体の他、数平均分子量が７００以上１５００以下のポリブデン等が用いられる。なお、ポリブデンの数平均分子量が７００以上１５００以下としたのは、数平均分子量が７００未満であると粘度が１Ｐａ・ｓ未満となり粘凋効果が低く、はんだペーストの印刷性が低下するからであり、数平均分子量が１５００を超えると耐熱性が高くなり残渣として残りやすくなるからである。
　このように本実施形態では、粘凋剤をロジン類、ダイマー酸、及び数平均分子量が１５００を超えるポリブデン等により構成していないことから、熱重量測定において３００℃での減少率が９０質量％以上となり、はんだバンプに残渣が残ることを抑制しつつ、粘凋性を確保している。
　なお、本実施形態のフラックスは、上述したようにロジン類等を主成分として含んでいないため、酸化物を還元除去して下地に濡らし、はんだバンプを被覆して再酸化を防止する効果に乏しい。このようなロジン類の機能は、後述するギ酸ガスにより補填している。 As a caking agent contained in the flux, one having a low decomposition temperature and having viscosity is preferable. For example, as the viscosity improver, isobornyl cyclohexanol, isobornyl phenol and derivatives thereof, polybden having a number average molecular weight of 700 or more and 1,500 or less, or the like is used. The reason why the number average molecular weight of polybden is 700 or more and 1,500 or less is because the viscosity is less than 1 Pa · s when the number average molecular weight is less than 700, the viscosity effect is low, and the printability of the solder paste is reduced. If the number average molecular weight exceeds 1,500, the heat resistance becomes high and it tends to remain as a residue.
As described above, in the present embodiment, since the caking agent is not composed of the rosins, the dimer acid, and the polybden having a number average molecular weight of more than 1,500, the reduction rate at 300 ° C. is 90% by mass in thermogravimetry. As described above, the viscosity is secured while suppressing the residue from remaining on the solder bumps.
In addition, since the flux of this embodiment does not contain rosins etc. as a main component as mentioned above, the oxide is reduced and removed to wet the base and the effect of covering the solder bumps and preventing reoxidation is poor. . The functions of such rosins are compensated by formic acid gas described later.
　このようなフラックスの配合組成は、例えば、溶剤が１９質量％～６０質量％、粘凋剤が３０質量％～８０質量％、チクソ剤が１．０質量％～１０質量％である。溶剤が１９質量％未満では、はんだペーストがペースト状になりにくく、溶剤が６０質量％を超えると、基板上に印刷塗布された状態のはんだペースト（以下、バンプ前駆体という場合がある）の形状保持性が不良となる。チクソ剤が１．０質量％未満では、はんだペーストの形状保持性が不良となり、１０質量％を超えると、はんだペーストが固くなりすぎる。また、粘凋剤が３０質量％未満の場合、ペーストを構成できないか、若しくは、乾いたペーストとなり、はんだペーストを基板などに塗布できないおそれがある。
　一方、粘凋剤が８０質量％を超えていると、はんだペーストの粘度が高くなりすぎる、若しくは、粘着力が高くなりすぎ、印刷時の掻き取り性が悪化し、あるいはディスペンサによる塗布時やピン転写時の形状が悪化するおそれがある。好ましいフラックスの配合組成は、粘凋剤が３５質量％以上８０質量％以下、チクソ剤が２質量％以上６質量％以下、残部が溶剤である。また、さらに好ましいフラックスの配合組成は、粘凋剤が３５質量％以上７０質量％以下、チクソ剤が２．５質量％以上５．５質量％以下、残部が溶剤である。
　なお、はんだペースト用フラックス内に活性剤が多量に含まれていると、はんだペーストとしたときのはんだ粉末とフラックスとが反応し、粘度変化が大きくなるので、冷蔵保存であっても数か月しか保存できない。このため、本実施形態では、はんだペースト用フラックスには、活性剤を含まないこととしている。 The composition of such a flux is, for example, 19% by mass to 60% by mass of the solvent, 30% by mass to 80% by mass of the caking agent, and 1.0% to 10% by mass of the thixotropic agent. If the solvent content is less than 19% by mass, the solder paste does not easily become paste-like, and if the solvent content exceeds 60% by mass, the shape of the solder paste (hereinafter referred to as bump precursor) in a print applied state on the substrate. The retention is poor. If the thixotropic agent is less than 1.0% by mass, the shape retention of the solder paste becomes poor, and if it exceeds 10% by mass, the solder paste becomes too hard. If the viscosity is less than 30% by mass, the paste can not be formed or becomes a dry paste, and there is a possibility that the solder paste can not be applied to a substrate or the like.
On the other hand, if the viscosity exceeds 80% by mass, the viscosity of the solder paste becomes too high or the adhesive strength becomes too high, and the scraping property at the time of printing deteriorates, or when applying by a dispenser or pin The shape at the time of transfer may be deteriorated. The preferable composition of the flux is 35% by mass to 80% by mass of the caking agent, 2% by mass to 6% by mass of the thixotropic agent, and the remaining portion being the solvent. Moreover, as for the composition of further preferable flux, 35 mass% or more and 70 mass% or less of a caking agent, 2.5 mass% or more and 5.5 mass% or less of a thixo agent, and a remainder are solvents.
If a large amount of activator is contained in the flux for solder paste, the solder powder and flux react with each other when made into solder paste, and the viscosity change becomes large. Can only save. For this reason, in the present embodiment, the flux for solder paste does not contain an activator.
［はんだペーストの構成］
　はんだペーストは、上述したフラックスと、はんだ粉末とを混合してなる混合体であり、フラックスの含有率が３０体積％以上９０体積％以下に設定されている。はんだペースト用フラックスの含有率が３０体積％未満の場合、ペーストを構成できないか、若しくは、乾いたペーストとなり、はんだペーストを基板などに印刷塗布できないおそれがある。一方、はんだペースト用フラックスの含有率が９０体積％を超えていると、はんだペーストの粘度が高くなりすぎる、若しくは、粘着力が高くなりすぎ、印刷時の掻き取り性が悪化し、あるいはディスペンサによる塗布時やピン転写時の形状が悪化するおそれがある。このため、本実施形態では、フラックスの含有率が３０体積％以上９０体積％以下に設定されている。なお、フラックスの含有率は、４０体積％以上９０体積％以下であることが好ましい。
　これにより、はんだペーストの粘度は、０．４Ｐａ・ｓ以上となり、はんだペーストのタッキング力は、０．８Ｎ以上となる。 [Composition of solder paste]
The solder paste is a mixture of the flux and the solder powder, and the content of the flux is set to 30% by volume or more and 90% by volume or less. When the content rate of the flux for solder paste is less than 30% by volume, the paste can not be formed or becomes a dry paste, and there is a possibility that the solder paste can not be applied to a substrate or the like by printing. On the other hand, if the content of the solder paste flux exceeds 90% by volume, the viscosity of the solder paste becomes too high, or the adhesive strength becomes too high, and the scraping property at the time of printing deteriorates, or The shape at the time of application or at the time of pin transfer may be deteriorated. For this reason, in the present embodiment, the flux content is set to 30% by volume or more and 90% by volume or less. The content of the flux is preferably 40% by volume or more and 90% by volume or less.
As a result, the viscosity of the solder paste is 0.4 Pa · s or more, and the tacking force of the solder paste is 0.8 N or more.
　また、はんだ粉末としては、Ｓｎ－Ａｇ－Ｃｕはんだ粉末、Ｓｎ－Ｃｕはんだ粉末、Ｓｎ－Ａｇはんだ粉末、Ｐｂ－Ｓｎはんだ粉末、Ａｕ－Ｓｎはんだ粉末、Ａｕ－Ｇｅはんだ粉末を例示できる。また、はんだ粉末の平均粒径は、例えば、０．１～３０．０μｍの範囲内にあり、これによりマスク開口部へのペースト充填性及びバンプ前駆体の形状保持性を高めることができる。
　なお、バンプ形成を狭ピッチにするためには、はんだ粉末の平均粒径は、０．１～１０．０μｍの範囲内にあることが好ましい。 Further, examples of the solder powder include Sn-Ag-Cu solder powder, Sn-Cu solder powder, Sn-Ag solder powder, Pb-Sn solder powder, Au-Sn solder powder, and Au-Ge solder powder. Also, the average particle diameter of the solder powder is, for example, in the range of 0.1 to 30.0 μm, which can enhance the paste filling property to the mask opening and the shape retention property of the bump precursor.
In order to narrow the bump formation, the average particle diameter of the solder powder is preferably in the range of 0.1 to 10.0 μm.
［はんだバンプの形成方法］
　次に、はんだペーストを用いたはんだバンプの形成方法を説明する。
　この形成方法は、はんだペーストを印刷する印刷工程と、はんだペーストをギ酸ガス雰囲気下で加熱するリフロー工程と、を備える。以下、印刷工程、リフロー工程の順に詳細を説明する。 [Method of forming solder bumps]
Next, a method of forming solder bumps using a solder paste will be described.
This formation method includes a printing step of printing a solder paste, and a reflow step of heating the solder paste in a formic acid gas atmosphere. Hereinafter, details will be described in the order of the printing process and the reflow process.
（印刷工程）
　印刷工程では、シリコンウェーハ、ガラスエポキシ樹脂基板等の基板上に開口部を有するマスクを配置し、この開口部内にはんだペーストを充填するようにはんだペーストを印刷塗布する。この印刷塗布後、マスクを基板から剥離して、基板上にバンプ前駆体を形成する。なお、はんだペーストは、印刷塗布されることとしたが、ディスペンサ等による吐出供給でもよいし、ピン転写装置等によるピン転写でもよい。
　この場合、粘凋剤が常温で固体又は粘度が１Ｐａ・ｓ以上の液体であるため、粘凋剤を含むはんだペースト用フラックス及びはんだ粉末からなるはんだペーストの形状保持性を確保できる。また、はんだペースト用フラックスの含有率が３０体積％以上９０体積％以下であることから、適切な粘度及び粘着力のはんだペーストを構成でき、印刷時の掻き取り性の悪化等を抑制できる。 (Printing process)
In the printing process, a mask having an opening is disposed on a substrate such as a silicon wafer or a glass epoxy resin substrate, and a solder paste is applied by printing so as to fill the opening with the solder paste. After the printing application, the mask is peeled off from the substrate to form a bump precursor on the substrate. Although the solder paste is applied by printing, it may be discharged and supplied by a dispenser or the like, or may be pin transferred by a pin transfer device or the like.
In this case, since the caking agent is a solid at room temperature or a liquid having a viscosity of 1 Pa · s or more, it is possible to ensure the shape retention of the solder paste flux and the solder powder containing the caking agent. Moreover, since the content rate of the flux for solder paste is 30 volume% or more and 90 volume% or less, the solder paste of appropriate viscosity and adhesiveness can be comprised, and the deterioration of the scraping property at the time of printing etc. can be suppressed.
（リフロー工程）
　リフロー工程では、まず予備加熱として、ギ酸ガス雰囲気下で、基板上に形成されたバンプ前駆体をはんだ粉末の融点より低い温度で３０秒～２分加熱し（プレヒート工程）、フラックス中のボイド源である溶剤を揮発させる。このギ酸ガス雰囲気下での各ヒート工程は、常温でＮ２を純度９９％のギ酸にバブリングすることによりＮ２ガス内にギ酸を溶け込ませたガスを発生させ、このギ酸が溶け込んだＮ２ガスを炉内に供給することにより実行される。このギ酸が溶け込んだＮ２ガス（ギ酸ガス）のギ酸濃度は、例えば、略３体積％に設定される。なお、炉内にギ酸を置くことによりギ酸ガス雰囲気を生成してもよい。
　その後、はんだ粉末の融点より高い温度、例えば、はんだ粉末の融点＋３０℃の温度で１０秒～１分加熱し（本ヒート工程）、はんだ粉末を溶融する。この際、ギ酸は、はんだ粉末に含まれるＳｎなどの金属酸化物と反応してギ酸塩を生成した後、さらに高温化に置かれることでギ酸塩がギ酸により還元される。このようにギ酸ガス雰囲気下において、各ヒート工程を実行すると、ギ酸の還元力によりはんだ粉末等の酸化被膜が還元される。そして、溶融したはんだを冷却すると、表面張力により略半球状のはんだバンプが形成される。 (Reflow process)
In the reflow process, first, as a preheating, the bump precursor formed on the substrate is heated under a formic acid gas atmosphere at a temperature lower than the melting point of the solder powder for 30 seconds to 2 minutes (preheating process). Volatilize the solvent. Each heat process under the formic acid gas atmosphere, to generate a gas was dissolve formic acid to N 2 in the gas by bubbling N 2 at room temperature in 99% formic acid, N 2 to dissolved gases in this formic acid Is carried out by supplying The formic acid concentration of the N 2 gas (formic acid gas) in which the formic acid is dissolved is set to, for example, about 3% by volume. The formic acid gas atmosphere may be generated by placing formic acid in the furnace.
Thereafter, the solder powder is heated by heating for 10 seconds to 1 minute (main heat step) at a temperature higher than the melting point of the solder powder, for example, the temperature of the melting point + 30 ° C. of the solder powder (main heating step). At this time, formic acid is reacted with a metal oxide such as Sn contained in the solder powder to form a formic acid salt, and then the formic acid salt is reduced by formic acid by being placed at a higher temperature. As described above, when each heating process is performed in a formic acid gas atmosphere, an oxide film such as a solder powder is reduced by the reducing power of formic acid. Then, when the molten solder is cooled, a substantially hemispherical solder bump is formed by surface tension.
　この場合、本実施形態では、はんだペースト用フラックスが熱重量測定において３００℃での減少率が８０質量％以上であり、その中でも粘凋剤が熱重量測定において３００℃での減少量が９０質量％以上であるため、はんだペースト用フラックスを含むはんだペーストがリフローされた際に、フラックスとしても揮発分が多いため、バンプ前駆体がリフローされてはんだバンプが形成された場合であっても、残渣が発生することを抑制でき、はんだバンプの洗浄工程を省くことができる。
　また、ギ酸ガス雰囲気下でリフロー処理がなされるので、はんだペーストを構成するフラックス内に酸化物を還元除去するロジン類が含まれていなくても、ギ酸ガスの還元力によりはんだ粉末や基板上の酸化被膜を還元してはんだ溶融を円滑にできる。 In this case, in the present embodiment, the flux for solder paste has a reduction rate at 300 ° C. of 80 mass% or more in thermogravimetry, and among them, the reduction amount of the caking agent at 300 ° C. in thermogravimetry is 90 mass % Or more, when a solder paste containing a flux for solder paste is reflowed, there is also a large amount of volatile component as a flux, so even if a bump precursor is reflowed to form a solder bump, a residue Can be suppressed and the process of cleaning the solder bumps can be omitted.
In addition, since reflow processing is performed in a formic acid gas atmosphere, even if the flux constituting the solder paste does not contain rosins for reducing and removing oxides, the reducing power of the formic acid gas causes the solder powder and the substrate to be reduced. The oxide film can be reduced to facilitate solder melting.
　また、本実施形態のはんだペースト用フラックスを使用することで残渣の発生が抑制されるので、はんだ粉末が高融点のＡｕ－Ｓｎはんだ粉末であってもリフロー時の残渣の飛び跳ねを防止できる。
　さらに、はんだペースト用フラックスの酸価値が１００ｍｇＫＯＨ／ｇ以下に設定されているので、はんだバンプ内におけるボイドの発生を抑制できる他、はんだペーストを長期間（例えば、６か月以上）保存でき、長期保管性を向上できる。 In addition, since generation of a residue is suppressed by using the flux for a solder paste of the present embodiment, it is possible to prevent jumping of the residue at the time of reflow even if the solder powder is a high melting point Au-Sn solder powder.
Furthermore, since the acid value of the flux for solder paste is set to 100 mg KOH / g or less, generation of voids in the solder bump can be suppressed, and the solder paste can be stored for a long time (for example, 6 months or more). Storage can be improved.
　なお、本発明は上記実施形態に限定されることはなく、本発明の趣旨を逸脱しない範囲において種々の変更を加えることが可能である。
　上記実施形態では、フラックスは、粘凋剤、溶剤、及びチクソ剤のみから構成されることとしたが、これに限らず、酸価値が１００ｍｇＫＯＨ／ｇ以下であり、熱重量測定において３００℃での減少率が８０質量％以上の範囲内であり、粘度が０．５Ｐａ・ｓ以上であり、かつ、タッキング力が１．０Ｎ以上であれば、フラックスはロジン類及び活性剤を微量に含んでもよい。例えば、ロジン類の場合は１０質量％以下、活性剤の場合は０．１質量％以下の範囲であれば、フラックスにこれらを含んでもよい。
　また、上記実施形態では、リフロー工程においてプレヒート工程及び本ヒート工程を実行することで、加熱温度を二段階で段階的に上昇させることとしたが、これに限らず、本ヒート工程のみを実行してもよい。また、加熱温度を三段階以上で段階的に上昇させてもよい。
　さらに、上記実施形態では、はんだペーストを用いたはんだバンプの製造方法について説明したが、これに限らず、本発明のはんだペーストは、接合物と被接合物との間に配置され、ギ酸ガス雰囲気下で加熱することによって接合物と被接合物とをはんだ接合する、接合体の製造方法に用いられてもよい。 The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
In the above embodiment, the flux is composed only of the caking agent, the solvent, and the thixotropic agent, but not limited thereto, the acid value is 100 mg KOH / g or less, and the thermogravimetric measurement at 300 ° C. If the reduction rate is in the range of 80% by mass or more, the viscosity is 0.5 Pa · s or more, and the tacking force is 1.0 N or more, the flux may contain a slight amount of rosins and an activator. . For example, in the case of rosins, it may be contained in the flux as long as it is in the range of 10% by mass or less and in the case of an activator, 0.1% by mass or less.
In the above embodiment, the heating temperature is raised stepwise in two steps by performing the preheating step and the main heating step in the reflow step, but the present invention is not limited to this, and only the main heating step is performed. May be Also, the heating temperature may be raised stepwise in three or more steps.
Furthermore, although the said embodiment demonstrated the manufacturing method of the solder bump using a solder paste, the solder paste of not only this but this invention is arrange | positioned between a joining thing and a to-be-joined thing, and the formic acid gas atmosphere It may be used for the manufacturing method of a joined object which carries out the solder joint of a joined thing and a thing by heating below.
　諸条件を変更しながら、はんだペーストを製造し、このはんだペーストから得られるはんだバンプのリフロー後の残渣の量、はんだペーストの長期保管性及び形状保持性に関する実験を行った。得られた実施例１～９及び比較例１～６のサンプルについて、表１及び表２を参照しながら説明する。 Solder pastes were manufactured while changing various conditions, and experiments were conducted on the amount of residue after reflow of the solder bumps obtained from the solder paste, the long-term storability of the solder paste, and the shape retention. The obtained samples of Examples 1 to 9 and Comparative Examples 1 to 6 will be described with reference to Tables 1 and 2.
　なお、表１においてフラックス及び粘凋剤のそれぞれにおける熱重量測定における３００℃での減少率（以下、表１では３００℃ＴＧ減少という）については、一般の熱重量測定装置を用いて測定した。例えば、フラックスの熱重量測定では、１０ｍｇのフラックスをＮ２雰囲気下で、昇温１０℃／ｍｉｎ、室温（２５℃）から３００℃まで温度を上昇させたときの重量変化を測定することにより、上記減少率を求めた。粘凋剤も同様である。
　また、フラックス及び粘凋剤の粘度については、ＪＩＳ　Ｚ　８８０３に準拠して測定した。なお、表１では、常温（２５℃）において液状のものについては、上記ＪＩＳ　Ｚ　８８０３に準拠して測定した粘度を表示し、常温において固体のものについては、表１に固体と表示した。
　さらに、フラックスの酸価値については、ＪＩＳ　Ｚ　３１９７に準拠して測定した。なお、酸価値が小さすぎて検出限界を超えているものについては、検出限界以下と表示した。 In Table 1, the rate of decrease at 300 ° C. in the thermogravimetric measurement of each of the flux and the caking agent (hereinafter, referred to as 300 ° C. TG decrease in Table 1) was measured using a general thermogravimetric measurement apparatus. For example, in the thermogravimetry flux, the flux of 10mg under N 2 atmosphere, heating 10 ° C. / min, by measuring the weight change when the temperature was raised to 300 ° C. from room temperature (25 ° C.), The above reduction rate was determined. The same is true for the thickeners.
Further, the flux and viscosity of the caking agent were measured in accordance with JIS Z 8803. In Table 1, the viscosity measured according to the above-mentioned JIS Z 8803 was displayed for the liquid one at normal temperature (25 ° C.), and the solid one at solid temperature was displayed as solid in Table 1.
Furthermore, the acid value of the flux was measured in accordance with JIS Z 3197. In addition, when the acid value was too small and exceeded the detection limit, it was displayed as below the detection limit.
　このような表１に示すはんだ粉末及びフラックスを表１に示す割合で混合することにより、はんだペーストを製造した。また、フラックスは粘凋剤、チクソ剤、溶剤、活性剤を混合することによって作製し、粘凋剤、チクソ剤、溶剤及び活性剤は表１記載の通りとし、チクソ剤は５質量％とし、残部を溶剤とした。
　リフロー後の残渣の有無、はんだペーストの長期保管性及び形状保持性についての評価を下記手法により行った。 A solder paste was manufactured by mixing the solder powder and the flux shown in Table 1 in the proportion shown in Table 1. The flux is prepared by mixing a thickener, a thixo agent, a solvent and an activator, and the thickener, thixo agent, solvent and activator are as described in Table 1, and the thixo agent is 5% by mass. The remainder was solvent.
Evaluation about the presence or absence of the residue after reflow, the long-term storability of a solder paste, and shape retention was performed by the following method.
（リフロー後の残渣の有無）
　銅板の表面に厚み２００μｍの印刷用ステンシルマスクを用いて、各実施例１～９及び比較例１～６のはんだペーストのそれぞれを直径６．５ｍｍの円形状に印刷塗布して、銅板から印刷用ステンシルマスクを除去した。このようにして、各試料について円形状のバンプ前駆体を銅板上に形成し、評価用基板とした。
　次に、ギ酸ガス雰囲気下において、この評価用基板を加熱することで、バンプ前駆体をリフロー処理させた。このとき、ピーク温度は各はんだ粉末の融点＋３０℃とし、加熱時間は１分とした。このギ酸ガス雰囲気下での加熱は、常温でＮ２をバブリングすることによりＮ２ガス内にギ酸を溶け込ませたガスを発生させ、このギ酸が溶け込んだＮ２ガスを炉内に供給することにより実行した。このギ酸が溶け込んだＮ２ガス（ギ酸ガス）のギ酸濃度は、略３体積％とした。
　その後、電子顕微鏡（ＳＥＭ）を用いて、リフロー処理されたバンプ前駆体（はんだバンプ）を観察し、残渣の面積がはんだペーストの塗布面積の３割未満の場合を良好と判定し、残渣がはんだペーストの塗布面積の３割以上を覆っている場合を不良と判定した。 (Presence of residue after reflow)
Using a 200 μm thick stencil mask for printing on the surface of a copper plate, the solder pastes of each of Examples 1 to 9 and Comparative Examples 1 to 6 are print-coated in a circular shape with a diameter of 6.5 mm, from the copper plate for printing The stencil mask was removed. In this manner, a circular bump precursor was formed on a copper plate for each sample, and was used as a substrate for evaluation.
Next, the bump precursor was subjected to a reflow process by heating the evaluation substrate in a formic acid gas atmosphere. At this time, the peak temperature was set to 30 ° C. of the melting point of each solder powder, and the heating time was set to 1 minute. The heating under formic acid gas atmosphere, room temperature to generate a gas was dissolve formic acid to N 2 in the gas by bubbling N 2 in, by supplying N 2 to dissolved gases in this formic acid in a furnace I did. The formic acid concentration of the N 2 gas (formic acid gas) in which this formic acid was dissolved was about 3% by volume.
Thereafter, the reflowed bump precursor (solder bump) is observed using an electron microscope (SEM), and the case where the area of the residue is less than 30% of the application area of the solder paste is judged to be good. The case where 30% or more of the application area of the paste was covered was determined to be defective.
（はんだペーストの長期保管性）
　ペーストを室温で６ヶ月間保管した後、このペーストを用いて上記と同じ評価用基板を作成し、これに上記リフロー処理を行ってはんだバンプを形成した。
　その後、光学顕微鏡で観察し、はんだ粉末の未溶融粉の発生量がはんだペースト作製直後と同じ場合を良好と判定し、はんだ粉末の未溶融粉の発生量がはんだペースト作製直後より増加した場合を不良と判定した。 (Long-term storage stability of solder paste)
After the paste was stored at room temperature for 6 months, the same evaluation substrate as described above was prepared using this paste, and the above-mentioned reflow process was performed thereon to form a solder bump.
After that, it is observed with an optical microscope, and it is determined that the generation amount of unmelted powder of the solder powder is the same as immediately after the solder paste preparation is good. It was determined to be defective.
（形状保持性）
　評価基板上にピッチ２００μｍ、開口径１２０μｍ、厚み２５μｍのマスクではんだペーストを塗布して、バンプ前駆体を１００個形成した。１００個のバンプ前駆体を形成した評価基板を目視、又は光学顕微鏡で観察し、１００個のはんだバンプ前駆体のうち、ミッシングが５箇所以下、印刷ダレによるブリッジが５箇所以下、バンプ前駆体の欠けが５箇所以下の場合を良好と判定し、ミッシング、ブリッジ及び欠けのいずれかが５箇所より多く発生している場合を不良と判定した。 (Shape retention)
Solder paste was applied onto the evaluation substrate with a mask having a pitch of 200 μm, an opening diameter of 120 μm, and a thickness of 25 μm to form 100 bump precursors. Of the 100 solder bump precursors, the evaluation substrate on which 100 bump precursors have been formed is observed visually or with an optical microscope, and the number of missing portions is 5 or less, the number of bridges due to printing sag is 5 or less, of the 100 bumps. The case where the number of chippings was five or less was judged as good, and the case where any of the missing, the bridge and the chiping occurred at more than five positions was judged as defective.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表１及び表２からわかるように、比較例１、３及び６は、フラックスの熱重量測定における３００℃での減少量が６０質量％以下と低いことから、リフロー後の残渣が発生した領域がはんだペーストの塗布面積の３割を超えており、リフロー後の残渣が多かった。一方、実施例１～９では、フラックスの熱重量測定における３００℃での減少率が８０質量％以上であったため、リフロー後の残渣が少なかった。また、比較例２、４及び５もフラックスの熱重量測定における３００℃での減少率が８０質量％以上であったため、リフロー後の残渣が少なかった。このため、フラックスの熱重量測定において、３００℃での減少量がいずれも８０質量％以上であることが有効な範囲であることがわかった。 As can be seen from Tables 1 and 2, in Comparative Examples 1, 3 and 6, since the decrease amount at 300 ° C. in the thermogravimetric measurement of the flux is as low as 60 mass% or less, the area where the residue after reflow is generated is It exceeded 30% of the application area of the solder paste, and there were many residues after reflow. On the other hand, in Examples 1 to 9, since the reduction rate at 300 ° C. in the thermogravimetric measurement of the flux was 80 mass% or more, there were few residues after reflow. Moreover, since the reduction rate in 300 degreeC in the thermogravimetric measurement of flux was 80 mass% or more also in Comparative example 2, 4 and 5, the residue after reflow was few. For this reason, in thermogravimetric measurement of the flux, it was found that it is an effective range that the reduction amounts at 300 ° C. are all 80 mass% or more.
　また、比較例１、２及び５は、フラックスの酸価値が２００～１５００ｍｇＫＯＨ/ｇと高いことから、長期保管性に劣っていた。一方、実施例１～９では、フラックスの酸価値が１００ｍｇＫＯＨ／ｇ以下であったため、はんだペーストの長期保管性に優れていた。また、比較例３、４及び６もフラックスの酸価値が検出限界以下であったため、はんだペーストの長期保管性に優れていた。このため、フラックスの酸価値が１００ｍｇＫＯＨ／ｇ以下であることが有効な範囲であることがわかった。
　なお、実施例２では、フラックスは、０．１質量％の活性剤を含んでいるが、フラックスの酸価値が１００ｍｇＫＯＨ／ｇ以下であるため、長期保管性に優れていた。一方、比較例２では、フラックスが０．２質量％の活性剤を含んでいることから、フラックスの酸価値が２００ｍｇＫＯＨ／ｇと高くなり、長期保管性が劣っていた。このため、フラックスの酸価値が上記範囲内であれば、０．１質量％以下の活性剤を含んでもよいことがわかった。 Further, Comparative Examples 1, 2 and 5 were inferior in long-term storage property because the acid value of the flux was as high as 200 to 1500 mg KOH / g. On the other hand, in Examples 1 to 9, since the acid value of the flux was 100 mg KOH / g or less, the long-term storability of the solder paste was excellent. Moreover, since the acid value of the flux was below the detection limit also in Comparative Examples 3, 4 and 6, the long-term storability of the solder paste was excellent. For this reason, it was found that it is an effective range that the acid value of the flux is 100 mg KOH / g or less.
In addition, in Example 2, although the flux contained 0.1 mass% activator, since the acid value of a flux is 100 mgKOH / g or less, it was excellent in long-term storage property. On the other hand, in Comparative Example 2, since the flux contains 0.2% by mass of the activator, the acid value of the flux is as high as 200 mg KOH / g, and the long-term storage stability is inferior. For this reason, it was found that if the acid value of the flux is within the above range, it may contain 0.1% by mass or less of the activator.
　比較例５ではフラックスが４０質量％の重合ロジンを含んでいることから、フラックスの酸価値が８００ｍｇＫＯＨ／ｇと高くなり、長期保管性が劣っていた。一方、実施例８では、フラックスは、重合ロジンを５質量％含んでいるものの、長期保管性に優れていた。
　また、比較例６では、フラックスが４０質量％のロジンエステルを含んでいることから、熱重量測定における３００℃での減少量が６０質量％以下と低くなり、リフロー後の残渣が多かった。一方、実施例９では、フラックスは、ロジンエステルを１０質量％含んでいるものの、リフロー後の残差が少なかった。
　これらのことから、フラックスの、酸価値、熱重量測定における３００℃での減少量が上記範囲内であれば、１０質量％以下のロジン類を含んでもよいことがわかった。 In Comparative Example 5, since the flux contains 40% by mass of the polymerized rosin, the acid value of the flux is as high as 800 mg KOH / g, and the long-term storage stability is inferior. On the other hand, in Example 8, although the flux contained 5% by mass of polymerized rosin, it was excellent in long-term storage performance.
Further, in Comparative Example 6, since the flux contains a rosin ester of 40% by mass, the reduction amount at 300 ° C. in thermogravimetric measurement is as low as 60% by mass or less, and the residue after reflow is large. On the other hand, in Example 9, although the flux contained 10% by mass of rosin ester, the residual after reflow was small.
From these facts, it was found that as long as the acid value of the flux and the reduction amount at 300 ° C. in thermogravimetric measurement fall within the above range, it may contain 10% by mass or less of rosins.
　さらに、比較例４は、フラックスの粘度が０．３Ｐａ・ｓと低く、タッキング力も０．８Ｎと小さいことから、印刷ダレ等が発生し、形状保持性が劣っていた。一方、実施例１～９は、フラックスの粘度が１Ｐａ・ｓ以上であり、タッキング力も１．０Ｎ以上であることから形状保持性に優れていた。また、比較例１～３及び５は、フラックスの粘度が０．５Ｐａ・ｓ以上であり、タッキング力も１．０Ｎ以上であることから、形状保持性に優れていた。このため、フラックスの粘度が０．５Ｐａ・ｓ以上であり、かつ、タッキング力が１．０Ｎ以上であることが有効な範囲であることがわかった。 Furthermore, in Comparative Example 4, since the viscosity of the flux was as low as 0.3 Pa · s, and the tacking force was also as small as 0.8 N, printing sag and the like were generated, and the shape retention was inferior. On the other hand, in Examples 1 to 9, since the viscosity of the flux was 1 Pa · s or more and the tacking force was 1.0 N or more, the shape retention was excellent. Further, in Comparative Examples 1 to 3 and 5, since the viscosity of the flux was 0.5 Pa · s or more and the tacking force was 1.0 N or more, the shape retention was excellent. For this reason, it was found that it is an effective range that the viscosity of the flux is 0.5 Pa · s or more and the tacking force is 1.0 N or more.
　電子部品の基板への接合の信頼性を効率良く向上させることができる。 The reliability of bonding of the electronic component to the substrate can be efficiently improved.

Claims (7)

  1. 　粘凋剤、溶剤、及びチクソ剤を含むはんだペースト用フラックスであって、酸価値が１００ｍｇＫＯＨ／ｇ以下であり、熱重量測定において３００℃での減少率が８０質量％以上であり、粘度が０．５Ｐａ・ｓ以上であり、かつ、タッキング力が１．０Ｎ以上であることを特徴とするはんだペースト用フラックス。 A flux for solder paste containing a viscosity improver, a solvent, and a thixotropic agent, which has an acid value of 100 mg KOH / g or less, a reduction rate at 300 ° C. of 80 mass% or more in thermogravimetry, and a viscosity of 0 The flux for solder paste, characterized in that it has a tacking force of 1.0 N or more.
  2. 　ロジン類の含有量が１０質量％以下であることを特徴とする請求項１に記載のはんだペースト用フラックス。 The flux for solder paste according to claim 1, wherein the content of the rosin is 10% by mass or less.
  3. 　請求項１又は２に記載のはんだペースト用フラックスと、はんだ粉末とを混合してなることを特徴とするはんだペースト。 A solder paste comprising the flux for solder paste according to claim 1 and a solder powder mixed with each other.
  4. 　前記はんだペースト用フラックスの含有率が３０体積％以上９０体積％以下であることを特徴とする請求項３に記載のはんだペースト。 The solder paste according to claim 3, wherein a content of the flux for the solder paste is 30% by volume or more and 90% by volume or less.
  5. 　前記はんだ粉末は、Ｓｎ－Ａｇ－Ｃｕはんだ粉末、Ｓｎ－Ｃｕはんだ粉末、Ｓｎ－Ａｇはんだ粉末、Ｐｂ－Ｓｎはんだ粉末、Ａｕ－Ｓｎはんだ粉末、Ａｕ－Ｇｅはんだ粉末、Ａｕ－Ｓｉはんだ粉末のいずれかであることを特徴とする請求項３又は４に記載のはんだペースト。 The solder powder may be any of Sn-Ag-Cu solder powder, Sn-Cu solder powder, Sn-Ag solder powder, Pb-Sn solder powder, Au-Sn solder powder, Au-Ge solder powder, and Au-Si solder powder. The solder paste according to claim 3 or 4, characterized in that
  6. 　開口部を有するマスクを基板上に配置し、前記開口部内に請求項３から５のいずれか一項に記載のはんだペーストを充填するように前記はんだペーストを印刷し、前記マスクを剥離した後前記基板上のバンプ前駆体をギ酸ガス雰囲気下でリフロー処理してはんだバンプを形成することを特徴とするはんだペーストを用いたはんだバンプの形成方法。 A mask having an opening is disposed on a substrate, the solder paste is printed so that the solder paste according to any one of claims 3 to 5 is filled in the opening, and the mask is peeled off. What is claimed is: 1. A method of forming a solder bump using a solder paste, comprising the step of reflowing a bump precursor on a substrate in a formic acid gas atmosphere to form a solder bump.
  7. 　はんだペーストを用いた接合体の製造方法であって、
    　接合物と被接合物との間に請求項３から５のいずれか一項に記載のはんだペーストを配置し、ギ酸ガス雰囲気下で加熱することによって前記接合物と前記被接合物とをはんだ接合することを特徴とするはんだペーストを用いた接合体の製造方法。     A method of manufacturing a joined body using a solder paste, comprising
    The solder paste according to any one of claims 3 to 5 is disposed between a joint and an object, and the joint and the object are soldered by heating in a formic acid gas atmosphere. A manufacturing method of a joined body using solder paste characterized by doing.
PCT/JP2018/028062 2017-07-28 2018-07-26 Solder paste flux, solder paste, method for forming solder bump using solder paste, and method for producing joined body WO2019022193A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
KR1020197031518A KR102122166B1 (en) 2017-07-28 2018-07-26 Flux for solder paste, solder paste, method of forming solder bumps using solder paste, and method of manufacturing joined body
CN201880027120.7A CN110603120B (en) 2017-07-28 2018-07-26 Flux for solder paste, method for forming solder bump using solder paste, and method for manufacturing bonded body

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2017-147084 2017-07-28
JP2017147084 2017-07-28
JP2018133872A JP6566095B2 (en) 2017-07-28 2018-07-17 Flux for solder paste, solder paste, method for forming solder bump using solder paste, and method for manufacturing joined body
JP2018-133872 2018-07-17

Publications (1)

Publication Number Publication Date
WO2019022193A1 true WO2019022193A1 (en) 2019-01-31

Family

ID=65039661

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2018/028062 WO2019022193A1 (en) 2017-07-28 2018-07-26 Solder paste flux, solder paste, method for forming solder bump using solder paste, and method for producing joined body

Country Status (1)

Country Link
WO (1) WO2019022193A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20220019708A (en) 2019-06-20 2022-02-17 세키스이가가쿠 고교가부시키가이샤 Conductive material, bonded structure, and manufacturing method of bonded structure
WO2023037974A1 (en) * 2021-09-09 2023-03-16 三菱マテリアル株式会社 Bonded body, method for manufacturing bonded body, and method for evaluating organic residues of bonded body

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008246563A (en) * 2007-03-30 2008-10-16 Fujitsu Ltd Solder paste, component mounting method and component mounting apparatus
JP2014138019A (en) * 2013-01-15 2014-07-28 Takeo Kuramoto Method for manufacturing solder bump, and transfer sheet or peeling sheet used for the same
JP2016078095A (en) * 2014-10-21 2016-05-16 三菱マテリアル株式会社 Formation method of solder bump

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008246563A (en) * 2007-03-30 2008-10-16 Fujitsu Ltd Solder paste, component mounting method and component mounting apparatus
JP2014138019A (en) * 2013-01-15 2014-07-28 Takeo Kuramoto Method for manufacturing solder bump, and transfer sheet or peeling sheet used for the same
JP2016078095A (en) * 2014-10-21 2016-05-16 三菱マテリアル株式会社 Formation method of solder bump

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20220019708A (en) 2019-06-20 2022-02-17 세키스이가가쿠 고교가부시키가이샤 Conductive material, bonded structure, and manufacturing method of bonded structure
WO2023037974A1 (en) * 2021-09-09 2023-03-16 三菱マテリアル株式会社 Bonded body, method for manufacturing bonded body, and method for evaluating organic residues of bonded body
JP7392698B2 (en) 2021-09-09 2023-12-06 三菱マテリアル株式会社 Conjugated body, method for manufacturing the conjugated body, and method for evaluating organic residue in the conjugated body

Similar Documents

Publication Publication Date Title
JP4079026B2 (en) No residue solder paste
TWI394633B (en) No-clean low-residue solder paste for semiconductor device applications
TWI270432B (en) Residue-free solder paste
TWI666086B (en) Solder bump forming method
JP7022434B2 (en) Flux for solder paste and solder paste
JP6383544B2 (en) Flux composition for soldering and method for producing electronic substrate using the same
JP2019055428A (en) Flux and solder paste
WO2015178374A1 (en) Method for forming solder bump, and solder paste for fixing solder ball
WO2019022193A1 (en) Solder paste flux, solder paste, method for forming solder bump using solder paste, and method for producing joined body
JP6937093B2 (en) Flux composition and solder paste
JP5850206B2 (en) Flux for cleaning and solder paste for cleaning
JP2014195830A (en) Flux for lead-free solder for clearance resist, and lead-free solder paste for clearance resist
JP6566095B2 (en) Flux for solder paste, solder paste, method for forming solder bump using solder paste, and method for manufacturing joined body
KR102525010B1 (en) Flux and solder paste
TW201607992A (en) Solder flux composition
JP2011083809A (en) Flux, solder paste and joined part
JP2008062242A (en) Flux for soldering, and solder paste composite
JP5635561B2 (en) Solder composition
JP6506046B2 (en) Solder bump reflow method
JP5218837B2 (en) Method of forming solder bump
JP2008062241A (en) Solder paste composition
JP2017170480A (en) HIGH-TEMPERATURE SERVICE Pb-FREE SOLDER PASTE, AND MANUFACTURING METHOD THEREOF
JP2020116637A (en) Paste for joining and bump forming method and production method of joined body using the paste for joining
JP2020131257A (en) Flux and solder paste

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18838809

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 20197031518

Country of ref document: KR

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 18838809

Country of ref document: EP

Kind code of ref document: A1