WO1994014563A1

WO1994014563A1 - Soldering method and apparatus

Info

Publication number: WO1994014563A1
Application number: PCT/JP1993/001868
Authority: WO
Inventors: Shinji Kon; Keiki Ariga; Tsutomu Inamura; Toyoyuki Sato; Hidetoshi Ohta; Akitoshi Hirao; Tetsuya Okuno; Tomohiko Iino
Original assignee: Nippon Sanso Corporation; Senju Metal Industry Co., Ltd.
Priority date: 1992-12-25
Filing date: 1993-12-24
Publication date: 1994-07-07

Abstract

A method of carrying out soldering in an atomsphere of a mixed gas of vapor of diketone and/or vapor of carboxylic acid, and an inert gas and/or a reducing gas (exclusive of a mixed gas of vapor of carboxylic acid and an inert gas). A soldering apparatus is provided with a soldering furnace (10), a path (20) for supplying an inert gas to the soldering furnace (10), a path (40) for supplying a reducing gas to the same, a path (60) for supplying vapor of diketone and/or vapor of carboxylic acid to the same, and first and second mixers (80, 81) for mixing the vapor of diketone and/or the vapor of carboxylic acid, with an inert gas and/or a reducing gas therein.

Description

Description Soldering method and equipment Technical field

The present invention relates to a method and an apparatus for soldering, and more particularly, to a method and an apparatus for soldering in an active atmosphere. Background art

For good soldering, the surface of the base material (the object to be soldered) must be clean when the solder material is melted. For this reason, the surface of the base material is generally cleaned (activated) using a flux. The soldering method using this flux involves the steps of arranging the flux at the soldered portion of the base material, and covering the soldered portion with the flux while activating the surface of the base material by heating to maintain the active state. The process is broadly divided into the process of melting the solder material and spreading the solder material on the activated base material surface, and the process of solidifying the solder material by cooling and joining the solder material to the base material.

The flux used in the above method has the power to evaporate to some extent due to heating during soldering. <Some of the flux remains in the soldered area. If the remaining flux is left as it is, the flux reacts with the moisture (moisture) in the air and corrodes the soldered parts, lowers the insulation resistance, and degrades the functions of electronic devices, for example. Inconvenience occurs. '

Therefore, electronic devices and other devices that value reliability are washed after soldering to remove the flux. On the other hand, typical fluxes include, for example, rosin to which an active ingredient such as an amine halide is added. As a solvent for removing these, chlorofluorocarbon and trichlene have excellent effects. However, the use of these solvents has been regulated because they destroy the ozone layer surrounding the earth and contaminate groundwater.

Due to this situation, in recent years, soldering factories for electronic equipment have used the above solvents. Although alternative cleaning methods such as water-soluble cleaning alcohols have been developed, which are beginning to consider cleaning methods that do not use them, there is an inconvenience in that the processing of the alternative cleaning method in which the flux is cleaned requires a great deal of cost. Therefore, development of a soldering method and a device that does not use a flux that requires cleaning is desired.

Therefore, an object of the present invention is to provide a soldering method and an apparatus which does not use a flux, activates a soldered portion by an atmospheric gas, and does not require cleaning after soldering. Disclosure of the invention

The method of the present invention is a method of mixing a mixture of a diketone vapor and / or a carboxylic acid vapor with an inert gas and Z or a reducing gas (excluding a mixed gas of a carboxylic acid vapor and an inert gas). This includes soldering in an atmosphere.

The apparatus of the present invention is designed for use in an atmosphere of a mixture of diketone vapor and Z or carboxylic acid vapor with an inert gas and / or a reducing gas (excluding a mixture of carboxylic acid vapor and an inert gas). A soldering furnace for performing soldering below, a path for supplying the diketone and / or carboxylic acid to the soldering furnace, and a path for supplying the inert gas and / or reducing gas to the soldering furnace. Is included.

The mixed gas used in the present invention includes a mixed gas of diketone vapor and an inert gas, a mixed gas of diketone vapor and an inert gas and carboxylic acid vapor, and a mixed gas of diketone and inert gas. Mixed gas of active gas and reducing gas, mixed gas of steam of diketone, inert gas and power Mixed gas of steam of rubonic acid and reducing gas, mixed gas of steam of diketone and reducing gas, diketone Mixed gas of mixed gas of vapor of carboxylic acid and reducing gas, mixed gas of mixed gas of carboxylic acid vapor and reducing gas, or mixed gas of mixed gas of carboxylic acid vapor and reducing gas and inert gas Either.

The wearer's own hair ton used in the present invention, Jiasechiru _{(CH 3 C 0 C 0 C} Η 3, boiling point 87 ° C), § cetyl acetone _{_{_{(CH 3 COCH 2 C OCH 3}}} , boiling point 140. 5 .C), It is at least one of acetonylacetone (CH ₃ C 0 CH ₂ CH ₂ COCH ₃ , boiling point 191.4 ° C).

The carboxylic acid used in the present invention is formic acid (HC OOH, boiling point 101 ° C), Acetic acid (CH ₃ C 0 OH, boiling point 119 ° C), propionic acid (CH ₃ (CH ₂ ) CO OH, boiling point 141.C), petitic acid (CH ₃ (CH ₂ ) ₂ C 00 H, Boiling point 164 ° C), phenolic acid (CH ₃ (CH ₂ ) ₃ CO OH, boiling point: 86 ° C), hydroproic acid (CHp (CH ₂ ) ₄ COOH, boiling point 205 ° C) ), Enanthic acid (CH ₃ (CH „) ₅ CO OH, boiling point 233 ° C), caprylic acid (CH ₃ (CH ₀ ) _β C 0 OH, boiling point 239 ° C), pelargonic acid (CH. ₂ ) ₇ C OOH, boiling point 253 ° C), oxalic acid ((HC OOH) ₂ , boiling point 157 ° C (sublimation)), malonic acid (HOOC (CH 2) COOH, boiling point 14 CTC), succinic acid ( HOO C (CH ₂ ) C OOH, boiling point 235. C (sublimation)), acrylic acid (CH ₂ CH C OOH, boiling point 141 ° C), salicylic acid (C ₆ H ₄ (OH) C OOH, Boiling point: 21 1 ° C; (sublimation) :), Lactic acid (CH ₃ CH (OH) COOH, Boiling point: 119 ° C).

The inert gas used in the present invention is at least one of nitrogen, carbon dioxide, argon, and helium.

The reducing gas used in the present invention is at least one of hydrogen, carbon monoxide, and ammonia.

The diketone vapor used in the present invention may be any one of the inert gas, the reducing gas, or the mixed gas of the reducing gas and the inert gas by any of the following methods. Can be mixed with gas.

First, any one of the gases is bubbled in the diketone liquid. Second, the diketone liquid is introduced into any one of the gases and evaporated. Third, the diketone liquid is introduced into a soldering furnace in an atmosphere of any of the above gases and evaporated.

Fourth, the vapor of the diketone is condensed on the base material to form a liquid film or droplets, and the base material on which the diketone is condensed is heated at a high temperature in a soldering furnace in an atmosphere of any of the above gases. And evaporate again.

In the fifth step, the diketone liquid is introduced into a soldering furnace in an atmosphere of any one of the above gases, and a liquid film or droplets are formed on the base material and then evaporated.

The carboxylic acid vapor used in the present invention may be any one of the reducing gas or the mixed gas of the reducing gas and the inert gas by any one of the following methods. Gas.

Part 1, the one of the gas, the 2 to Baburi ring into the liquid of the carboxylic acid, the any of the gas, _c No.3 evaporation by introducing a liquid of the carboxylic acid, the one The carboxylic acid solution is introduced into a soldering furnace in an atmosphere of such a gas and evaporated.

Fourth, the vapor of the carboxylic acid is condensed on the base material to form a liquid film or droplets, and the base material on which the carboxylic acid is condensed is heated at a high temperature in a soldering furnace in an atmosphere of any of the above gases. Heat once and evaporate again.

In the fifth step, the liquid of the carboxylic acid is introduced into a soldering furnace under an atmosphere of any of the above gases, and a liquid film or a droplet is formed on the base material and then evaporated.

The mixed steam of the diketone and the carboxylic acid used in the present invention may be obtained by any one of the following methods: the inert gas, the reducing gas, or the reducing gas and the inert gas. Can be mixed with any of the mixed gas.

In the first step, any one of the gases is bound to the diketone liquid and the carboxylic acid liquid.

In the second step, the diketone liquid and the carboxylic acid liquid are introduced into any one of the gases and evaporated.

Third, the diketone solution and the carboxylic acid solution are introduced into a soldering furnace in an atmosphere of any of the above gases and evaporated.

The fourth step is to introduce the diketone solution and the carboxylic acid solution into a soldering furnace in an atmosphere of any of the above gases, form a liquid film or droplets on the base material, and evaporate them. ο

The diketone liquid and the carboxylic acid liquid in (1) to (4) may be either separate or mixed.

In the fifth step, the mixed vapor of the diketone and the carboxylic acid is condensed on the base material to form a liquid film or droplets. Heat in a high-temperature zone of a soldering furnace under any gas atmosphere and evaporate again o

In the sixth step, the vapor of the diketone is condensed on the base material to form a liquid film or droplets. The base material on which the ketone is condensed is heated again in a high-temperature zone of a soldering furnace under an atmosphere of any one of the gases and the vapor of the carboxylic acid to evaporate again.

In the sixth aspect, the carboxylic acid vapor is converted into the inert gas, the reducing gas, or the mixed gas of the reducing gas and the inert gas by any one of the following methods. Can be mixed.

Part 1, the one gas, _t Part 2 to Baburi ring into the liquid of the carboxylic acid, the any of the gas, _c No.3 evaporation by introducing a liquid of the carboxylic acid, the The carboxylic acid solution is introduced into a soldering furnace under an atmosphere of any of the gases and evaporated.

The liquid film or droplet of the diketone on the base material according to the present invention can be formed by any of the following methods.

In the first method, the temperature of the diketone vapor is raised to a temperature equal to or higher than the temperature of the inlet of the soldering furnace or the temperature of the base material before introducing the soldering furnace, and then supplied to the soldering furnace.

The second is that the diketone vapor is added to the inert gas, the reducing gas, or a mixed gas of the reducing gas and the inert gas, and the temperature of the inlet of the soldering furnace or Mix so that the saturated vapor pressure is equal to or higher than the temperature of the base material before introducing the soldering furnace, and supply it to the soldering furnace.

In the present invention, the formation of the liquid film or droplet of the carboxylic acid on the base material can be performed by any of the following methods.

First, the temperature of the carboxylic acid vapor is raised to a temperature equal to or higher than the temperature of the inlet of the soldering furnace or the temperature of the base material before the introduction of the soldering furnace, and then supplied to the soldering furnace.

The second is that the carboxylic acid vapor is introduced into either the reducing gas or the mixed gas of the reducing gas and the inert gas, and the temperature of the inlet of the soldering furnace or the introduction of the soldering furnace. Mix and supply to the soldering furnace so that the vapor pressure becomes higher than the saturated vapor pressure at the temperature of the previous base metal.

In the present invention, the formation of the mixed liquid film or droplet of the diketone and the carboxylic acid on the base material can be performed by any of the following methods.

The first is to raise the temperature of the mixed vapor of the diketone and the carboxylic acid to a temperature equal to or higher than the temperature of the inlet of the soldering furnace or the temperature of the base material before the introduction of the soldering furnace. To supply.

The second is that the mixed steam of diketone and carboxylic acid is added to the inert gas, the reducing gas, or the mixed gas of the reducing gas and the inert gas, were mixed so that the saturated vapor pressure of each of the temperature of the temperature or soldering furnace before introduction of the base material of the inlet portion, the to _c the soldering furnace is supplied to the soldering furnace wearer's own hair Bokun'oyobi Z or carboxylic One of the paths for supplying the acid is a path for supplying the diketone and Z or carboxylic acid in a liquid state to the soldering furnace.

The second of the paths for supplying the diketone and Z or the carboxylic acid to the soldering furnace includes means for dew condensation of the diketone and Z or the carboxylic acid on a base material to form a liquid film or a droplet state. I have.

The means for forming the liquid film or the droplet state is a nozzle for discharging the diketone and / or carboxylic acid, or a device for foaming the diketone and / or carboxylic acid. The third of the paths for supplying the diketone and / or carboxylic acid to the soldering furnace includes the means for evaporating the diketone and / or Z or carboxylic acid.

One of the diketone evaporating means supplies the soldering furnace with either the inert gas, the reducing gas, or a mixed gas of the reducing gas and the inert gas. A diketon bubbling tank connected to a path.

O o

The second of the diketone evaporation means is connected to a path for supplying the inert gas, the reducing gas, or the mixed gas of the reducing gas and the inert gas to the soldering furnace. This is a mixer for introducing the above-mentioned diketone liquid, heating and evaporating the mixed liquid to mix these gases.

The first of the carboxylic acid evaporating means is connected to a path for supplying either the reducing gas or a mixed gas of the reducing gas and the inert gas to the soldering furnace. This is a carboxylic acid bubbling tank.

The second of the carboxylic acid evaporating means is connected to a path for supplying the reducing gas or a mixed gas of the reducing gas and the inert gas to the soldering furnace. By introducing the liquid and heating it to evaporate, This is a mixer that mixes with the gas.

One of the evaporating means for the diketone and the carboxylic acid may be any one of the inert gas, the reducing gas, and the mixed gas of the reducing gas and the inert gas in the soldering furnace. A bubbling tank of the diketone liquid and the carboxylic acid liquid, or a mixed liquid bubbling tank of these diketones.

The diketone and the second of the carboxylic acid evaporating means include a path for supplying the soldering furnace with the inert gas, the reducing gas, or a mixed gas of the reducing gas and the inert gas. A mixer for introducing the liquid of the diketone and the liquid of the carboxylic acid, heating and evaporating the mixed liquid to mix these gases.

In this mixer, two diketone mixers and a carboxylic acid mixer are connected, and a diketone liquid introduction path and a carboxylic acid liquid introduction path are connected to two mixers. Alternatively, an introduction path for a mixed liquid of the diketone liquid and the carboxylic acid liquid is connected to one mixer.

The conditions for the atmosphere gas to eliminate the need for cleaning after soldering are as follows: first, the atmosphere gas has the property of reducing the oxide film on the base metal and the solder surface. The material does not dissolve into the base material, or does not lower insulation resistance or generate corrosives even if it does.

After examining the composition of the atmosphere gas suitable for this condition, it was found that diketone vapor and / or carboxylic acid vapor having reducing properties at the soldering temperature were appropriate.

When diketone vapor is used, it is preferable to dilute the diketone vapor with an inert gas since the apparatus can be simplified. In addition, this stand is economical because the expensive diketone is used after diluting it, and the safety in handling the flammable gas of the diketone is improved.

However, since the activity of the diketone vapor is weak, if the oxygen concentration in the atmosphere increases or if the oxidation of the surface of the base material progresses slightly, the base material surface cannot be sufficiently reduced-the solder melts. Even if it does, it may not spread. The steam activity of this diketon Increasing the steam concentration of diketones is more effective in compensating for the sexual deficiency, but as mentioned earlier, simply increasing the steam concentration of diketones in the atmosphere is not economically or safely desirable. .

For this reason, it is recommended to attach liquid diketone to the base material and evaporate it in a high-temperature zone in a soldering furnace, so that high-concentration diketone vapors mainly cover the soldering area.

As a method of attaching the diketone to the base material in a liquid form, a method of applying the diketone liquid using a coating device such as a fluxer in advance can be considered, but from the viewpoint of simplification and miniaturization of the device, the coating device is used. It is desirable not to use Therefore, there is a method in which the base material or the base material and the solder are brought into contact with the base material in liquid form by bringing the vapor of the diketone into contact with the base material before being heated in a soldering furnace, and condensing part of the vapor of the diketone. Recommended. In addition, there is a method of adding a reducing gas and / or a carboxylic acid vapor in order to compensate for a lack of activity of the diketone vapor.

When carboxylic acid vapor is added to the mixed gas of diketone vapor and inert gas, there are the following advantages in flow soldering.

Carboxylic acid vapors have a stronger reducing power than diketone vapors, but are often toxic. Therefore, it is desirable that the concentration of the carboxylic acid vapor be as low as possible. However, a low-concentration base in which only carboxylic acid vapor is mixed in an inert gas can reduce oxides in the jet solder, but it is not enough to reduce the surface of the base metal. Does not spread to the soldered part of the printed circuit board (base material).

On the other hand, diketone vapor is not toxic, but its activation is weak, so it is necessary to supply high-concentration vapor to the soldering part. It is desirable to attach liquid diketone to the base material in terms of economy and safety. However, when the oxygen concentration in the atmosphere at the time of soldering is relatively high (for example, 100 ppm), the solder spreads over the soldered portion of the printed board, but adheres to the printed board. Insufficient reduction of the solder surface. As a result, the surface tension of the solder increases, causing icicles on the lower surface of the printed circuit board.

Therefore, by using the vapor of the diketone and the vapor of the carboxylic acid at the same time, it is possible to compensate for the disadvantages of each other and perform good soldering. For example, the print group The diketone is attached to the soldered portion of the board in a liquid form and evaporated when the solder jet contacts the printed circuit board. If a small amount of acid vapor is added, the solder wets and spreads on the soldered portion, and no icicles are formed on the solder. As a result, good soldering becomes possible.

Further, the same effect as described above can be obtained even when the reducing gas is mixed with diketone vapor.

One of the methods for mixing the diketone vapor into the atmosphere gas includes, for example, a method for bubbling the reducing gas or a mixed gas of the reducing gas and the inert gas into the diketone liquid, After the inert gas is bubbled in the diketone liquid, a method of mixing the gas with a reducing gas can be adopted. At this time, by heating the diketone liquid below the boiling point, the vapor concentration of the diketone in the mixed gas can be increased.

Next, the carboxylic acid and one of the reducing gases, for example, hydrogen, also satisfy the above-mentioned condition as an atmospheric gas for eliminating the need for cleaning after soldering.

For example, a copper base and a copper surface are reduced by the following chemical reaction.

2 (R-C 0 0 H) + Cu 0 = (R-COO) ₂ Cu + H ₂ 0 (1) H ₂ + Cu 0 = Cu + H ₂ 0 (2) (where R Represents hydrogen or various hydrocarbon groups.)

However, in practice, when soldering at 200 ° C with carboxylic acid vapor or the atmosphere of the above reducing gas alone, the reducing power is weak, so the oxide film of the base material is completely removed. The solder material does not melt and spread on the base metal surface. For example, hydrogen cannot reduce oxides on the copper surface unless it is above about 350 ° C. Further, the surface of formic acid, which is a monocarboxylic acid, cannot be reduced without adding a small amount of a halogen component. In other words, the vaporization of carboxylic acid or a stage using the above-mentioned reducing gas alone, the effect of activating the base material by increasing the temperature is obtained. << Heating to a temperature higher than 250 ° C This may adversely affect electronic components, which is not preferable. Then, utilizing the interaction between the vapor of the carboxylic acid and the reducing gas, for example, (R—C 00) ₂ Cu produced by the reaction of the above formula (1) is converted into copper by hydrogen in the following reaction. To reduce.

(R-C 00) ₂ Cu + H = 2 (R-C OOH) + Cu (3) This reaction can also be inferred by observing the copper surface, when using only steam, a reaction product (R- C 00) but ₂ C u to I redo surface is green, by adding hydrogen, that will appear鋦表surface with a metallic luster .

That is, by using a mixed gas of carboxylic acid vapor and the reducing gas or a mixed gas of carboxylic acid vapor, the reducing gas and the inert gas as the soldering atmosphere gas, for example, copper The copper oxide on the surface is reduced to copper by the reactions of the above formulas (1) and (3), and the surface is activated.

As the reducing gas, in addition to the above-described hydrogen, carbon monoxide and ammonia are suitable. Carbon monoxide reacts with the water generated by the above formula (1) to generate hydrogen by the following formula 3.

C 0 + H ₂ 0 = C 0 ₂ + H ₂

Ammonia generates hydrogen by decomposing as shown below.

Also, various diketones and carboxylic acids can be used. Force <, temperature during soldering process, that is, soldering process depends on preheating of base material, melting of solder material, The process of cooling the solder material is roughly divided into three processes.The reduction of the surface of the base material needs to start from the process of preheating the base material.Therefore, the gas at the preheating temperature, that is, the general preheating temperature of 100 to 250, is used. Needs to be selected. Therefore, the aforementioned diketones and carboxylic acids are preferred.

In the present invention, depending on the condition of the surface of the base material, diketone vapor, or diketone vapor and carboxylic acid vapor, diketone vapor and reducing gas, diketone vapor and sulfonic acid vapor are used. A reducing gas or a mixed gas of a carboxylic acid vapor and a reducing gas can be used as an atmosphere gas for soldering. By mixing and diluting these, economic efficiency can be improved. In addition, for example, the concentration of hydrogen, which is a combustible gas, and the concentration of toxic carboxylic acid can be reduced, and safety can be improved. At this time, the above-mentioned nitrogen gas or the like can be used as the inert gas ffl.

The composition of the atmosphere gas for soldering depends on the type of base material, surface condition of base material, equipment configuration, temperature during soldering, composition and flow rate of mixed gas, etc. It is desirable to set

In addition, when the oxide film on the base metal surface is relatively thin, the safety and economy can be further improved by reducing the concentration of diketone vapor, carboxylic acid vapor and reducing gas. In addition, the diketone vapor, carboxylic acid vapor, and reducing gas contained in the soldering atmosphere gas activate and reduce the oxide film on the base metal and solder surface, resulting in good wetting of the base metal and solder material. In addition, since the components of the atmosphere gas hardly dissolve in the solder material or the base material, there is no decrease in insulation resistance or generation of corrosive substances, and good soldering can be performed. Furthermore, unlike the conventional case, no flux remains in the soldered part, eliminating the need for a washing step after soldering, and reducing equipment costs and running costs by eliminating a washing device. Can be achieved. In addition, since no solvent such as chlorofluorocarbon is used, there is no risk of environmental pollution. Water treatment when using a water-soluble detergent for cleaning is not required, and no space is required for installing a water treatment device together with the cleaning device. become. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a system diagram showing one embodiment of a soldering apparatus used in the method of the present invention. FIG. 2 is a system diagram showing a modified example of the supply route of diketone and / or carboxylic acid in FIG.

FIG. 3 is a system diagram showing another modified example of the supply route of diketone and di- or carboxylic acid in FIG.

FIG. 4 is a system diagram showing still another modified example of the supply route of diketone and carboxylic acid in FIG. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the method and apparatus of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of a method and an apparatus for supplying diketone vapor and / or carboxylic acid vapor by bubbling.

The apparatus shown in FIG. 1 is composed of a soldering furnace 10, a path 20 for supplying an inert gas, a path 40 for supplying a reducing gas, a steam of diketone and / or A steam supply path 60 is provided, and a first mixer 80 and a second mixer 81 for mixing the diketone vapor and the methane or carboxylic acid vapor with an inert gas and / or a reducing gas are provided. Have.

The path 20 for supplying the inert gas may be any of a small liquefied gas container (ELF) 21, a liquefied gas storage tank (CE) 22, or a pressure-variable air separation device (PSA) 23 as an inert gas supply source. Or have. The small liquefied gas container 21 or the liquefied gas storage tank 22 includes an evaporator 24 for evaporating the liquefied gas stored therein.

The path 25 of the inert gas from the pressure fluctuation type air separation device 23 or the evaporator 24 is connected to the above-mentioned through a shutoff valve 26, a filter 27, a pressure reducing valve 28, a flow control valve 29 and a flow indicator 30. Connected to first mixer 80. An inert gas path 31 branching downstream of the pressure reducing valve 28 in the inert gas path 25 is connected to the second mixing unit 8] through a flow control valve 32 and a flow indicator 33. Is done.

The path 40 for supplying the reducing gas connects the container 41 filled with the reducing gas and the first mixer 80, and shuts off between the container 41 and the first mixer 80. A valve 42, a filter 43, a pressure reducing valve 44, a flow control valve 45, a flow indicator 46 and a shutoff valve 47 are provided. The flow control valve 45 and the flow indicator 46 may be, for example, a mass flow controller 90 in which these are integrated.

The path 60 for supplying the vapor of diketone and the vapor of carboxylic acid or carboxylic acid includes a path 62 for supplying a bubbling gas to a bubbling tank 61 of diketone and / or carboxylic acid; 1A path 64 connects the mixer 80 via a shut-off valve 63, and a path 66 connects the bubbling tank 61 and the second mixer 81 via a shut-off valve 65. . A path 62 for supplying the bubbling gas is connected to a bubbling gas mixer 67. The path 25 for supplying the inert gas and the bubbling gas mixer 67 are connected via a path 34 branched from the upstream of the shutoff valve 26. The passage 34 has a shutoff valve 35, a filter 36, a pressure reducing valve 37, a flow control valve 38, and a flow indicator 39. The flow control valve 38 and the flow indicator 39 may be, for example, a mass flow controller 9] in which these are integrated.

The path 40 for supplying the reducing gas and the bubbling gas mixer 67 are connected via a path 48 branched from the downstream of the flow indicator 46. The path 48 has a shut-off valve 49.

Atmosphere gas introduction pipes 11, 12, 13 and 14 are connected to the soldering furnace 10 in this order from the upstream side in the transport direction of the material to be soldered. The atmosphere gas introduction pipes 11 and 12 are connected to the first mixer 80 via a path 15. The atmosphere gas introduction pipes 13 and 14 are connected to the second mixer 81 via a path 16 _{c. The} atmosphere gas introduction pipes 12 and 13 are shut off. Valve 7] is connected. An exhaust path 19 having an exhaust gas treatment device 8 is connected downstream of the soldering furnace 1 mm.

Next, a method of performing soldering in an atmosphere of a diketone vapor, a carboxylic acid vapor, a mixed gas of an inert gas and a reducing gas will be described with reference to FIG. The mixed solution of the diketone and the carboxylic acid is stored in the bubbling tank 61.

On the other hand, the soldering furnace 10 is purged with the inert gas introduced through a path 20 for supplying the inert gas to reduce the oxygen concentration in the furnace to a predetermined concentration or less. When it is confirmed that the oxygen concentration has become equal to or lower than the predetermined concentration, the first mixer 80 and the second mixer 81 are connected via the paths 25 and 31 of the path 20 for supplying the inert gas. Is supplied with an inert gas. In addition, an inert gas is supplied to the above-mentioned bubbling gas mixer 67 via a path 34. Further, the reducing gas is supplied to the first mixer 80 via a path 40 for supplying the reducing gas. A reducing gas is supplied to the bubbling gas mixer 67 via a path 48.

The mixed gas of the inert gas and the reducing gas supplied to the bubbling gas mixer 67 is supplied to the bubbling tank 61 to mix the diketone and the carboxylic acid.

Three The mixture is bubbled, and the mixture of the diketone and the carboxylic acid is entrained, and the mixture is passed through the routes 64 and 66 to the first mixer 80 and the second mixer 81. Supplied. The gas mixed in the first mixer 80 is introduced into the soldering furnace 10 through the path 15 and the atmosphere gas introduction pipes 11 and 12. The gas mixed in the second mixer 81 is introduced into the soldering furnace 10 through the path 16 and the atmosphere gas introduction pipes 13 and 14. As a result, the inside of the soldering furnace 10 becomes an atmosphere of a diketone vapor, a carboxylic acid vapor, a mixed gas of an inert gas and a reducing gas, and soldering is performed in the furnace by a predetermined method.

The gas in the soldering furnace 10 is detoxified by an exhaust gas treatment device 18 and discharged from an exhaust passage 19.

By adjusting the flow rates of the inert gas and the reducing gas with the flow control valves in each path, the composition of the atmosphere gas can be appropriately set.

The mixed vapor of the diketone and the carboxylic acid can be increased by heating the mixed liquid of the diketone and the carboxylic acid to a boiling point or lower.

Even if dedicated bubbling tanks are provided in series or in parallel, the mixed vapor of diketone and carboxylic acid can be obtained.

The bubbling gas supplied to the bubbling tank 61 may be either an inert gas or a reducing gas.

By opening and closing the shut-off valve 17, both or any of the paths 15 and 16 can be used.

Further, the bubbling tank 61 may store either the diketone or the carboxylic acid. In this case, the path 20 for supplying the inert gas or the path 40 for supplying the reducing gas may be omitted, or the shutoff valve of the path 20 or the path 40 may be closed to reduce the diketone. Mixed gas of vapor and inert gas, Mixed gas of diketone vapor, inert gas and carboxylic acid vapor, Mixed gas of diketone vapor, inert gas and reducing gas, Diketone vapor Mixed gas with steam and reducing gas, mixed gas of steam of diketone and steam of carboxylic acid and reducing gas, mixed gas of steam of carboxylic acid and reducing gas, or steam and reducing gas of carboxylic acid Any atmosphere gas of a mixed gas of a gas and an inert gas can be obtained. FIG. 2 shows a modified example of the supply route of the diketone and the di- or carboxylic acid in FIG.

The apparatus includes a mixer 82 connected to the soldering furnace 1 °, a path 25 for supplying the inert gas, and a path 4 for supplying the reducing gas, and supplies the inert gas. A mixer 83 connecting the path 34 and the path 48 for supplying the reducing gas, a container 67 storing a diketone and a liquid of carboxylic acid or carboxylic acid, and a path 68 from the container 67 Is mixed by evaporating the diketone and / or carboxylic acid liquid supplied via the mixing device 83 and the mixed gas of the inert gas and the reducing gas supplied from the mixer 83 via the path 84. And a path 86, 87 for supplying the gas mixed by the mixer 85 to the soldering furnace 10.

The path 86 is connected via a shut-off valve 89 to a path 88 connecting the mixer 82 and the atmospheric gas introduction pipes 11, 12. The path 87 is connected to the atmosphere gas introduction pipes 13 and 14. The container 67 is provided with a replenishing path 71 having a liquid level gauge 69, a liquid replenishing valve 70, and a pressurizing path 72 used as needed. The path 68 has a shutoff valve 73 and a flow rate instruction controller 74. The mixer 85 has a heater 92.

According to this apparatus, the diketone and / or carboxylic acid liquid is heated by the mixer 85 to evaporate and is mixed with a mixed gas of an inert gas and a reducing gas, and the soldering furnace 10 Supplied to

In this apparatus, a dedicated container may be provided for each of the mixers 85, and the mixer 85 may be provided for each of them.

The gas supplied to the mixer 85 may be either an inert gas or a reducing gas.

FIG. 3 shows another modified example of the supply route of the diketone and Ζ or carboxylic acid in FIG.

In this apparatus, the path 68 in FIG. 2 is directly connected to the soldering furnace 10. This passage 68 is branched into three introduction pipes 75, 76, and 77 and connected to the soldering furnace 1 #. A shutoff valve 78 is provided between the introduction pipes 75 and 76. The mixed gas of the inert gas and the reducing gas is mixed in the same manner as in Fig. 2. They are mixed in a mixer 82 and introduced into the soldering furnace 10.

According to this apparatus, the diketone and the liquid of carboxylic acid are directly introduced into the soldering furnace 10 and evaporated in the soldering furnace 10 to mix the inert gas and the reducing gas. Mix with platform gas. In this case, the diketone and / or carboxylic acid solution may be evaporated immediately in the furnace, or may be directly sprayed on the base material to form a liquid film or droplets and then evaporated.

In this apparatus, a dedicated container may be provided for each.

FIG. 4 shows a further modification of the supply route of diketone and carboxylic acid in FIG.

In this apparatus, a carboxylic acid solution is stored in a container 67 in FIG. 3, and the carboxylic acid solution is introduced into the soldering furnace 10 via a path 68. The diketone liquid stored in the container 93 is introduced into the soldering furnace 10 via a path 94. The path 94 is branched into two introduction pipes 95 and 96, and the tip is connected to the preheating zone 10a of the soldering furnace 1 #. Injection nozzles or foaming devices 97, 98 are provided at the tips of the introduction pipes 95, 96, respectively. The container 93 is provided with a replenishing path 1.01 having a liquid level meter 99, a liquid replenishing valve 100, and a pressurizing path 102 used as needed. The path 94 has a shutoff valve 103 and a flow rate instruction controller 104.

According to this apparatus, the diketone liquid is directly sprayed onto the base material disposed in the preheating zone 1 ◦a of the soldering furnace 10 via an injection nozzle or a foaming apparatus 97, 98. A liquid film or droplet is formed on the surface of the material. The diketone liquid film or droplet evaporates when the base material is transported to the high-temperature zone 1 Ob of the soldering furnace 10 and mixes with the atmospheric gas.

As an example of the foaming method of the foaming device, a cylindrical drum having a large number of fine holes is arranged on a liquid surface of a container containing a liquid to be foamed (diketone or carboxylic acid), and the drum is rotated. There is a method of forming a foam on the surface of the drum by discharging gas from the inside of the drum through the plurality of holes.

In addition, the temperature of the diketone or carboxylic acid is increased to a temperature higher than the temperature of the inlet of the soldering furnace 10 or the temperature of the base material before the soldering furnace 10 is introduced, and then supplied to the soldering furnace 10. Then, the diketone vapor and the carboxylic acid vapor dew to form a liquid film or droplet on the surface of the base material.

Further, the diketone or carboxylic acid is heated to a temperature equal to or higher than the saturated vapor pressure at the temperature of the inlet of the soldering furnace or at the temperature of the base material before the introduction of the soldering furnace, and the inert gas or the reducing property is reduced. When mixed with either a gas or a mixed gas of the reducing gas and the inert gas and supplied to the soldering furnace 1 mm, diketone vapor or carboxylic acid vapor condenses, and Forming Liquid Film or Droplet on Surface of Base Material Hereinafter, Experimental Examples and Comparative Examples of the present invention will be described.

Experimental example 1

In a flow soldering apparatus consisting of a preheater, a solder jet, and a cooling section, soldering experiments were performed while maintaining the atmosphere shown in Table 1. The conditions such as the solder composition were as follows.

Solder composition 63% tin, 37% lead

Solder temperature 25 CTC

Board used Composite board

Substrate transfer speed 1 m Z min

table 1

Before soldering

Operating atmosphere Oxygen concentration Soldering result Copper surface condition of the board a + ^ hand creature 1 z z% / 0 "*" empty 3Ε. Table ¾, π π n m

100 p pm Poor wet spread <10 ρ ρm Slight oxidation poor No wet spread

00

Acetyl acetone (condensation) + nitrogen <10 ρ ρ m

100 ρ ρ m good

1000 p pm good

5000 ppm Somewhat good Icicles generated <10 ρpm Somewhat good oxidation

Acetyl acetone (condensation) + formic acid 0.5% <10 ρ ρ m Luster Good

100 ρ pm good

1000 ρ ρ m good

5000 ρ pm good

As shown in Table 1, if the surface condition of the board before soldering is slightly oxidized or the oxygen concentration in the atmosphere is high, the solder does not spread on the soldering surface. When acetyl acetone (diketone) was condensed, the soldering result was good even if the surface condition of the substrate before soldering was slightly oxidized and the oxygen concentration in the atmosphere was somewhat high. However, when the oxygen concentration in the atmosphere reached 5000 ppm, the solder attached to the lower surface of the substrate became icicles.

Even after acetylacetone is condensed on the board and カルボン .5% of carboxylic acid vapor is added to the atmosphere, even if the oxygen concentration in the atmosphere becomes 5 OOO ppm, the solder Good soldering without wetting and spreading and no icing of solder is possible.

Experimental example 2

A ring solder material (63% tin, 37% lead) is placed on a polished copper plate, and soldering is performed at 200 ° C, 250 ° C, and 300 ° C using four types of atmosphere gases shown in Table 2. Was done. The acetyl acetate mixed gas was mixed by bubbling nitrogen or hydrogen into acetyl acetate heated to 80 ° C. Table 2

From Table 2, it can be seen that the use of a mixed gas of acetylaceton and hydrogen as the atmospheric gas enables soldering in a good condition at a relatively low temperature.

Experiment 3

An atmosphere gas consisting of hydrogen 20% as a reducing gas, formic acid 4% as a carboxylic acid gas, and the balance of inert gas nitrogen was used.On a polished copper plate and a copper oxide plate, tin 63% and lead 37% were used. Place the ring-shaped solder material, 200 ° C, 250 ° C, 300 ° C The state when heated was observed. The results are shown in Table 3.

Experiment 4

A soldering experiment was performed on a polished copper plate and a copper oxide plate in the same manner as in Experimental Example 3 using an atmospheric gas consisting of 40% hydrogen, 4% acetic acid, and the balance nitrogen. The results are shown in Table 3.

Comparative example

For comparison, soldering experiments were performed under the same conditions as in Experimental Examples 3 and 4, using only nitrogen, only hydrogen, nitrogen containing 4% formic acid, and nitrogen containing 4% fi acid as atmosphere gases. The results are shown in Table 3.

Polished copper plate Oxidized copper plate Heating temperature () 200 250 300 200 250 300 Hydrogen 20%, formic acid 4% Good Good Good Good Good Good

Balance nitrogen

Hydrogen 40%, acetic acid 4% good good good good good good good

Balance nitrogen

Bad Bad Bad Bad Bad Bad Bad Bad Bad Hydrogen Only Bad Bad Bad Bad Bad Bad Bad Bad Nitrogen containing 4% formic acid Poor Bad Good Bad Bad Good Bad Good Nitrogen containing 4% acetic acid Poor Bad Good Good Bad Good Bad Good Good

Claims

The scope of the claims

1. Soldering under the atmosphere of mixed gas of vapor of diketone and vapor of Z or carboxylic acid and inert gas and / or reducing gas (excluding mixed gas of vapor of carboxylic acid and inert gas) Soldering method including performing.

2. The soldering method according to claim 1, wherein the mixed gas is a mixed gas of diketone vapor and an inert gas.

3. The soldering method according to claim 1, wherein the mixed gas is a mixed gas of a diketone vapor, an inert gas, and a carboxylic acid vapor.

4. The soldering method according to claim 1, wherein the mixed gas is a mixed gas of diketone vapor, an inert gas, and a reducing gas.

5. The soldering method according to claim 1, wherein the mixed gas is a mixed gas of diketone vapor, inert gas, carboxylic acid vapor, and reducing gas.

6. The mixed gas is a mixed gas of diketone vapor and reducing gas. The soldering method described.

7. The soldering method according to claim 1, wherein the mixed gas is a mixed gas of diketone vapor, carboxylic acid vapor, and reducing gas.

8. The soldering method according to claim 1, wherein the mixed gas is a mixed gas of a carboxylic acid vapor and a reducing gas.

9. The soldering method according to claim 1, wherein the mixed gas is a mixed gas of a carboxylic acid vapor, a reducing gas, and an inert gas.

10. The soldering method according to claim 1, wherein the diketone is at least one of diacetyl, acetylacetone, and acetonylacetone.

1 1. The carboxylic acid is formic acid, acetic acid, propionic acid, pulic acid, valeric acid, caproic acid, enanthic acid, caprylic acid, berargonic acid, oxalic acid, malonic acid, succinic acid, acrylic acid, salicylic acid. And at least one of lactic acid. The method according to any one of I, 3, 5, 7, 8, 8, and 9.

1 2. The diketone vapor is the inert gas or the reducing gas. 2. The soldering method according to claim 1, wherein any one of the mixed gas of the reducing gas and the inert gas is mixed with the diketone by bubbling the mixed gas with the gas.

13. The vapor of the carboxylic acid is produced by bubbling either the reducing gas or a mixed gas of the reducing gas and the inert gas with a carboxylic acid liquid. 2. The soldering method according to claim 1, wherein the solder is mixed.

14. The mixed vapor of the diketone and the carboxylic acid may be any of the inert gas, the reducing gas, or the mixed gas of the reducing gas and the inert gas. 2. The soldering method according to claim 1, wherein the gas is mixed with a diketone solution and a carboxylic acid solution by bubbling them.

1 5. The diketone vapor is obtained by introducing the diketone liquid into the inert gas, the reducing gas, or a mixed gas of the reducing gas and the inert gas. 2. The soldering method according to claim 1, wherein the gas is mixed with these gases by evaporating.

16. The carboxylic acid vapor is introduced by introducing the carboxylic acid liquid into the reducing gas or a mixed gas of the reducing gas and the inert gas and evaporating the mixture. 2. The soldering method according to claim 1, wherein the mixed gas is mixed with a gas of the type described above.

17. The mixed steam of the diketone and the carboxylic acid may be any of the inert gas, the reducing gas, or the mixed gas of the reducing gas and the inert gas. 2. The soldering method according to claim 1, wherein the liquid is mixed with these gases by introducing and evaporating the liquid and the carboxylic acid liquid.

1 8. The steam of the diketone may be a soldering furnace in an atmosphere of either the inert gas or the reducing gas, or a mixed gas of the reducing gas and the inert gas. 2. The soldering method according to claim 1, wherein the diketone liquid is introduced and mixed with these gases by evaporation.

19. The carboxylic acid vapor is introduced into the soldering furnace under an atmosphere of either the reducing gas or the mixed gas of the reducing gas and the inert gas. 2. The soldering method according to claim 1, wherein the gas is mixed with these gases by evaporation.

20. The mixed vapor of the diketone and the carboxylic acid may be in an atmosphere of any of the inert gas, the reducing gas, or the mixed gas of the reducing gas and the inert gas. 2. The soldering method according to claim 1, wherein a diketone solution and a carboxylic acid solution are introduced into the soldering furnace, and then mixed with these gases by evaporation.

21. The steam of the diketon is formed by condensing the steam of the diketon on the base material to form a liquid film or a droplet, and converting the base material on which the diketone is condensed to the inert gas or the reduction. These gases are heated by a high-temperature zone of a soldering furnace under an atmosphere of either a reactive gas or a mixed gas of the reducing gas and the inert gas to evaporate the diketone again. 2. The soldering method according to claim 1, wherein the soldering method is mixed.

2 2. The carboxylic acid vapor condenses the carboxylic acid vapor on the base material to form a liquid film or droplets, and converts the carboxylic acid condensed base material to the reducing gas or the reduction. 2.The carboxylic acid is heated in a high-temperature zone of a soldering furnace under an atmosphere of a mixed gas of a reactive gas and the inert gas to evaporate the carboxylic acid again to mix with these gases. Soldering method.

23. The mixed vapor of the diketone and the carboxylic acid forms a liquid film or droplets by condensing the mixed vapor of the diketone and the carboxylic acid on the base material. The condensed base material is heated in a high-temperature zone of a soldering furnace under an atmosphere of the inert gas, the reducing gas, or a mixed gas of the reducing gas and the inert gas. 2. The soldering method according to claim 1, wherein the mixed solution of the diketone and the carboxylic acid is mixed with these gases by heating to evaporate the condensed liquid again.

24. The solder of the diketon is a soldering furnace in an atmosphere of the inert gas, the reducing gas, or a mixed gas of the reducing gas and the inert gas. 2. The soldering method according to claim 1, wherein the diketone liquid is introduced, a liquid film or droplets are formed on the base material, and then mixed with these gases by evaporation.

2 5. The vapor of the carboxylic acid is supplied to the soldering furnace under an atmosphere of either the reducing gas or the mixed gas of the reducing gas and the inert gas. To form a liquid film or droplets on the base material and then evaporate 3. The soldering method according to claim 1, wherein the gas is mixed with these gases.

26, the mixed vapor of the diketone and the carboxylic acid is in an atmosphere of either the inert gas, the reducing gas, or the mixed gas of the reducing gas and the inert gas. The liquid of the diketone and the liquid of the carboxylic acid are introduced into the soldering furnace, and a liquid film or droplets are formed on the base material, and then mixed with these gases by evaporation. Soldering method.

27. The vapor of the diketone is formed by condensing the vapor of the diketone on the base material to form a liquid film or a droplet, and converting the base material on which the diketone is condensed to the inert gas or the reduction. Heating in a high-temperature zone of a soldering furnace under an atmosphere of a reactive gas or a mixed gas of the reducing gas and the inert gas and the vapor of the carboxylic acid, to convert the diketone to 2. The soldering method according to claim 1, wherein the gas is mixed with these gases by evaporating again.

2 8. The vapor of the carboxylic acid causes the inert gas or the reducing gas, or the mixed gas of the reducing gas and the inert gas to be bubbled in the carboxylic acid liquid. 28. The soldering method according to claim 27, which is obtained by:

29. The vapor of the carboxylic acid may be a mixture of the inert gas or the reducing gas, or a mixed gas of the reducing gas and the inert gas. 28. The soldering method according to claim 27, obtained by introducing and evaporating.

30. The soldering method according to claim 27, wherein the vapor of the carboxylic acid is obtained by introducing the carboxylic acid liquid into the soldering furnace and evaporating the liquid.

31. The formation of a liquid film or droplets of the diketone on the base material may be performed by reducing the vapor of the diketone to a temperature equal to or higher than the temperature of the inlet of the soldering furnace or the temperature of the base material before introduction into the soldering furnace. 28. The soldering method according to claim 21 or 27, wherein the soldering is performed by raising the temperature to a soldering furnace.

32. The formation of the diketone liquid film or droplet on the base material is performed by using the inert gas, or the reducing gas, or the mixed gas of the reducing gas and the inert gas. Either of them is mixed with diketone steam so that the temperature is equal to or higher than the saturated vapor pressure at the inlet of the soldering furnace or at the temperature of the base material before introduction of the soldering furnace. 28. The soldering method according to claim 21 or 27, wherein the soldering is performed by supplying the solder to a soldering furnace.

3 3. The formation of the carboxylic acid liquid film or droplets on the base material is performed by raising the carboxylic acid vapor to a temperature equal to or higher than the temperature of the inlet of the soldering furnace or the temperature of the base material before introduction into the soldering furnace. 23. The soldering method according to claim 22, wherein the method is performed by heating and supplying the mixture to a soldering furnace.

3 4. The formation of the liquid film or droplet of the carboxylic acid on the base material may be performed by applying a carboxylic acid vapor to the reducing gas or a mixed gas of the reducing gas and the inert gas. 22. The method according to claim 22, wherein the mixing is performed so that the saturated vapor pressure is equal to or higher than the temperature at the inlet of the soldering furnace or the temperature of the base material before the introduction of the soldering furnace, and the mixture is supplied to the soldering furnace. Soldering method.

3 5. The mixed liquid film or droplet of the diketone and the carboxylic acid is formed on the base material by mixing the mixed vapor of the diketone and the carboxylic acid with the temperature at the inlet of the soldering furnace or the soldering furnace. 24. The soldering method according to claim 23, wherein the heating is performed by raising the temperature to a temperature equal to or higher than the temperature of the base material before the introduction and supplying the same to a soldering furnace.

3 6. The formation of the mixed liquid film or droplet of the diketone and the carboxylic acid on the base material is performed by the above-mentioned inert gas, the reducing gas, or the mixing of the reducing gas and the inert gas. A mixed gas of diketone and carboxylic acid is mixed with one of the mixed gases so as to have a temperature higher than the respective saturated vapor pressures at the inlet of the soldering furnace or at the temperature of the base material before the soldering furnace is introduced. 24. The soldering method according to claim 23, wherein the soldering is performed by supplying the solder to a soldering furnace.

3 7. Atmosphere of mixed gas of vapor of diketone and vapor of Z or carboxylic acid, and inert gas and gaseous or reducing gas (excluding mixed gas of vapor of carboxylic acid and inert gas) A soldering furnace for performing soldering below, a path for supplying the diketone and / or carboxylic acid to the soldering furnace, and a path for supplying the inert gas and Z or the reducing gas to the soldering furnace. Including soldering equipment.

38. The soldering apparatus according to claim 37, wherein a path for supplying the diketone and / or carboxylic acid to the soldering furnace includes a means for evaporating the diketone and / or carboxylic acid.

3 9. The evaporating means supplies the inert gas or the reducing gas to the soldering furnace. 39. The soldering apparatus according to claim 38, wherein the diketone wrapping tank is connected to a path for supplying either a reactive gas or a mixed gas of the reducing gas and the inert gas. .

40. The vaporizing means is connected to a path for supplying either the reducing gas or a mixed gas of the reducing gas and the inert gas to the soldering furnace. 39. The soldering device according to claim 38, wherein the device is a soldering tank. 41. The evaporating means is connected to a path for supplying the soldering furnace with the inert gas, the reducing gas, or a mixed gas of the reducing gas and the inert gas. 39. The soldering apparatus according to claim 38, wherein the apparatus is a publishing bath for the diketone liquid and the carboxylic acid liquid.

4 2. The evaporating means is connected to a path for supplying the inert gas, or the reducing gas, or a mixed gas of the reducing gas and the inert gas to the soldering furnace. 39. The soldering apparatus according to claim 38, wherein the mixing apparatus is a mixer for introducing a diketone liquid, heating the mixture, and evaporating the mixture to mix these gases.

4 3. The evaporating means is connected to a path for supplying the reducing gas or a mixed gas of the reducing gas and the inert gas to the soldering furnace. 39. The soldering apparatus according to claim 38, wherein the mixing apparatus is a mixer that mixes these gases by being introduced, heated, and evaporated.

44. The evaporation means is connected to a path for supplying the soldering furnace with the inert gas, the reducing gas, or a mixed gas of the reducing gas and the inert gas. 39. The soldering apparatus according to claim 38, wherein the soldering apparatus is a mixer for introducing a liquid of carboxylic acid and a liquid of the carboxylic acid, heating and evaporating the liquid to mix these gases.

45. The soldering apparatus according to claim 37, wherein the path for supplying the diketone and / or carboxylic acid to the soldering furnace is a path for supplying the diketone and / or carboxylic acid to the soldering furnace in a liquid state. .

46. The path for supplying the diketone and / or carboxylic acid to the soldering furnace includes means for dew condensation of the diketone and / or carboxylic acid on a base material to form a liquid film or a droplet state. A soldering apparatus according to claim 37.

47. The soldering apparatus according to claim 46, wherein the means for forming the liquid film or the droplet state is a nozzle for ejecting the diketone and / or carboxylic acid.

47. The soldering apparatus according to claim 46, wherein the means for forming the liquid film or the droplet state is a foaming device for the diketone and / or the carboxylic acid.