JPH09136158A - Soldering method - Google Patents

Abstract

(57) Abstract: In a soldering work of a solderable member, a residue of a soldering aid does not remain, it is friendly to a working environment, and cleaning after soldering can be omitted. The purpose is to provide. An organic compound having a bonding group having a bond dissociation energy of 550 KJ / mol or less and a boiling point lower than the soldering temperature is used as a soldering aid. For example, alcohols, ethers, higher fatty acids, which satisfy the conditions,
When an organic compound such as a hydrocarbon is used as an auxiliary agent, the oxide film of the member is removed due to the dissociation of the bonding group, and the member is wet with the solder, so that good soldering can be performed. In addition, the organic compound evaporates or decomposes depending on the soldering temperature, leaving no residue. In this way, the residue of the soldering aid does not remain, and the soldering work can be performed in a friendly working environment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soldering method using a soldering aid for facilitating soldering and for avoiding bridging of solder when metal-to-metal joining is performed using solder.

[0002]

2. Description of the Related Art In the case of performing metal-to-metal joining using solder, after cleaning the metal, a resin-based or inorganic-based flux is applied to the metal surface, and the solder is melted and soldered with a high-temperature soldering iron. Or, immersing the flux-coated metal in a high-temperature solder bath and soldering it, or coating the flux-containing solder on the metal surface and placing it in a heat treatment furnace for soldering. ing.

[0003]

However, in the above-mentioned conventional soldering method, a residue of flux remains, which corrodes the metal, and in electronic parts, causes deterioration of characteristics such as poor insulation and adversely affects the performance. Must be washed with a detergent to remove this residue.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a soldering method which does not require cleaning of flux residue after soldering and is also environmentally friendly.

[0005]

In order to achieve this object, the soldering method of the present invention uses an organic compound having a bonding group having a small dissociation energy and capable of evaporating or decomposing at a temperature during soldering. It is used as an agent and achieves the initial purpose.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the soldering method according to claim 1 of the present invention, since the bond dissociation energy of the bonding group of the auxiliary agent is as low as 530 KJ / mol at the maximum at the time of soldering, the bonding group can be easily bonded at the soldering temperature. Is dissociated, and at the time of dissociation, the oxide film on the surface of the member to be soldered is removed, and at the same time, the wettability between the member and the solder is improved and soldering can be performed. Further, since the organic compound used for soldering of the present invention evaporates or decomposes at the soldering temperature, it is possible to omit the cleaning for removing the residue after soldering.

(Embodiment 1) With respect to Embodiment 1 of the present invention, the joining of lead wires by soldering a ceramic electronic component having a silver electrode will be described below. For example, Sn
When soldering with 63% -Pb37% eutectic solder, the temperature of the solder is generally 200 to 300 ° C.
At that time, the bond dissociation energy is about 420 KJ / mol.
Then, N-butylcarbitol having a boiling point of about 230 ° C. is applied to the silver electrode and the lead wire as a soldering aid,
When soldering is performed by immersing in a solder bath at 300 ° C., good solder wettability is exhibited, and strong bonding can be performed.

[0008]

[Table 1]

The results will be described with reference to (Table 1). Solder temperature is less than 200-230 ° C (Experiment NO.
In 1), the wettability of the solder is good, but N-butyl carbitol slightly remains on the member to be soldered. However, it eventually evaporates without adversely affecting the members. Further, when the temperature of the solder is 230 to 280 ° C. or less (Experiment No. 2 to 4), the wetting of the solder is good, and N-butyl carbitol does not remain on the soldered member, which does not adversely affect the member. However, the solder temperature is 280-330 ° C (Experiment No. 5-6)
Then, the solder may adhere to or cross-link the ceramic part other than the silver electrode. Regarding the soldering characteristics and working problems according to this embodiment, a conventional example (Experiment No. 7-
It is shown in (Table 1) in comparison with 8). In addition, the experiment NO.
As is clear from No. 9, the same effect can be obtained by mixing.

The chemical structural formulas of the materials used in this example are shown in (Chemical formula 1). (Chemical formula 1) N = butyl carbitol: CH ₃ (CH ₂ ) ₃ (OCH ₂ C
H ₂ ) ₂ OH Octadecyl alcohol: C ₁₈ H ₃₇ OH Dodecyl alcohol: CH ₃ (CH ₂ ) ₁₁ OH (Embodiment 2) Hereinafter, Embodiment 2 of the present invention will be described with reference to (Table 2) and (Table 3). explain.

[0011]

[Table 2]

[0012]

[Table 3]

Here, in the same manner as in the first embodiment, in the joining of the electrode and the lead wire of the ceramic electronic component using solder, an organic material such as alcohols, ethers, saturated hydrocarbons and higher fatty acids is used as a soldering aid. The results are shown when the compound is used and silver, plated nickel, and plated copper are used for the electrodes of the ceramic electronic component. Solid NO. 13-15, NO. The organic compounds 20 to 23 are previously dissolved in an organic solvent to be a liquid for easy handling. As is clear from (Table 2), even if an organic compound such as alcohols, ethers, saturated hydrocarbons and higher fatty acids is used as a soldering aid, good soldering can be achieved as in the first embodiment. is there. The same result was obtained when nickel and copper were used for the electrode. That is, the experiment NO. 1
0, 13, 20, 23, 26, when the solder temperature is lower than the boiling point of the organic compound, the solder wettability is good, but the organic compound remains and it is desirable to wash. Experiment NO. 11,14,15,17,18,21,24,2
As is clear from 5, 27, when the boiling point of the organic compound is lower than the solder temperature and is within the range of -50 ° C from the solder temperature, the solder wettability is good, and there is no residue of the organic compound.
No need to wash. Experiment NO. 16, 17, 19, 2
As is clear from Nos. 2 and 28, when the boiling point of the organic compound is within the range of -50 ° C to -100 ° C from the solder temperature, the solder wettability is good and there is no residue of the organic compound, but it adheres to the ceramic part. Or crosslink. If the boiling point of the organic compound is -100 ° C or lower than the solder temperature, the solder wettability becomes extremely poor. Experiment No. 2
Conventional examples are shown in 9, 30, and 31. Experiment NO. 32 shows the result when an organic compound was mixed. That is, the same effect can be obtained by mixing the organic compound. In this embodiment, the electrode material is silver, nickel, and copper, and the lead wire is an NL wire (solder-plated copper wire). It goes without saying that are the same.

The chemical structural formula of the material used in this embodiment is shown in (Chemical Formula 2). (Chemical Formula 2) N-butyl carbitol: CH ₃ (CH ₂ ) ₃ (OCH ₂ C
H ₂ ) ₂ OH Dodecyl alcohol: CH ₃ (CH ₂ ) ₁₁ OH Dodecanediol: HO (CH ₂ ) ₁₂ OH Dibutyl ether: [CH ₃ (CH ₂ ) ₃ ] ₂ O Diamyl ether: [CH ₃ (CH ₂ ) ₄ ] ₂ O dodecanoic acid: CH ₃ (CH ₂ ) ₁₀ COOH octadecyl acid: C ₁₇ H ₃₅ COOH N-decane: C ₁₀ H ₂₂ N-dodecane: C ₁₂ H ₂₆ N-octadecane: C ₁₈ H ₃₈

[0015]

As described above, according to the present invention, in the joining of members by soldering, by using a soldering auxiliary agent having a bonding group having a small dissociation energy and having a boiling point slightly lower than the soldering temperature, The bonding group of the auxiliary agent is dissociated at the time of attachment, and at that time, the oxide film on the surface of the member to be soldered is removed, and the wettability between the member and the solder is improved. Also, since this auxiliary agent evaporates or decomposes at the soldering temperature, no auxiliary agent for soldering remains.
Cleaning of soldering aid residues is not required. Further, it is not necessary to install a cleaning device and a solvent recovery device for cleaning.
As described above, the soldering work can be realized which is simple, inexpensive, and excellent in working environment.

Front page continuation (72) Inventor Masafumi Goto 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (7)

[Claims] 1. A bond dissociation energy of up to 530 K as an auxiliary agent in soldering of solderable metals.
A soldering method comprising using an organic compound having a bonding group of J / mol or less and having a boiling point lower than the soldering temperature. 2. The organic compound is an alcohol group (R—OH).
The soldering method according to claim 1, wherein the soldering method is a polyhydric alcohol or a higher alcohol. 3. The organic compound is an ether group (R—O—
The soldering method according to claim 1, which is an organic compound having R '). 4. The organic compound is a saturated hydrocarbon (C
The soldering method according to claim 1, wherein the soldering method is _N H _{2N + 2} ). 5. The higher fatty acid (R-COO is used as the organic compound.
The soldering method according to claim 1, which is a compound H). 6. The soldering method according to claim 1, wherein when the organic compound is a solid at normal atmospheric temperature, it is dissolved or dispersed in a liquid organic solvent before use. 7. A polyhydric alcohol or a higher alcohol having an alcohol group, an organic compound having an ether group, two or more selected from the group consisting of saturated hydrocarbons and higher fatty acids, which are mixed and used as an auxiliary agent. The soldering method according to claim 1.