JPH0468089A - Flux cleaning agent - Google Patents

Abstract

PURPOSE:To obtain a flux cleaning agent which exhibits high detergency and good finish comparable with those of the conventional fluorocarbon or chlorine- base solvents by compounding specified alcohols and fatty acid esters. CONSTITUTION:A flux cleaning agent comprising at least one member selected from the group consisting of 3 to 4C alcohols and fatty acid esters. The cleaning agent has good detergency and finish comparable with those of the conventional fluorocarbon or chlorine-base solvents and does not destruct ozone. Further, the conventional apparatus for flux cleaning can be used substantially as they are, since the cleaning agent can easily be recovered by boiling or distillation by the use of a washing machine and a distiller which have been used for the recovery of the conventional fluorocarbon or chlorine-base solvents. In addition, water rinse for removing the cleaning agent from the washed article is not necessary in working steps, since it has a low boiling point and thus the washed article is ready to dry. Accordingly, there is no possibility of polluting water environment with waste water.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flux cleaning agent for removing flux applied during solder bonding to strengthen the bonding force between the solder and a base material after solder bonding.

[Conventional technology]

Conventionally, in the field of electrical and electronic industries, flux is applied in advance in order to firmly bond solder and base material in the manufacturing process of printed circuits or printed wiring boards. If this flux remains on the printed circuit or printed wiring board, it will cause poor conductivity or corrosion, so it is usually washed off with an organic cleaning agent after soldering. Freon 113 or methyl chloroform has conventionally been used as this cleaning agent. These solvents have a high ability to dissolve flux and are nonflammable, so they are widely used.

[Problem that the invention is trying to solve]

However, as society's awareness of environmental issues increases, there is a movement toward regulating the release of environmentally destructive substances into the atmosphere and water systems. For example, fluorocarbon solvents (5 types of specified fluorocarbons,
CFCII, CFCl2. CFCII3. C.F.C.
The use of I14°CFCII5) and methyl chloroform is being restricted as they are ozone depleting substances.

Under such circumstances, industries that use Freon 113 or methyl chloroform are urgently seeking a flux cleaning agent that can replace these solvents.

[Means to solve problems]

The present inventors have discovered that Freon 1 used in flux cleaning agents.
As a result of repeated research into cleaning agents that can replace methyl chloroform, a composition containing one or more alcohols having 3 to 4 carbon atoms and fatty acid esters as essential components has been found to be a substitute for conventional flux cleaning agents (Freon). The present inventors have discovered that the present invention is a cleaning agent that exhibits high cleaning performance and good finish quality comparable to those of 113 and methyl chloroform), and based on this knowledge, the present invention has been completed.

That is, the present invention is a flux cleaning agent characterized by containing as essential components: (1) one or more alcohols having 3 to 4 carbon atoms; and (2) fatty acid esters.

Regarding the composition of the alcohol having 3 to 4 carbon atoms and the fatty acid ester in the present invention, it is desirable that the concentration of the fatty acid ester is 10 to 30% by weight based on the total amount of the composition.

The alcohols having 3 to 4 carbon atoms used in the present invention include:
Examples include n-propanol, isopropanol, n-butanol, S-butanol, isobutanol, and t-butanol. These may be used alone or in combination of two or more.

Examples of fatty acid esters used in the present invention include ethyl acetate, propyl acetate, isopropyl acetate, 5ec.
-butyl, isobutyl acetate, isoamyl acetate, methyl n-butyrate, ethyl n-butyrate, ethyl propionate, isobutyl formate, ethyl isovalerate, and the like. These may be used alone or in combination of two or more.

The combination of essential components in the present invention can be arbitrarily changed depending on the material and form of the object to be washed, the type of dirt, etc. Among the essential components, if alcohol is missing, fatty acid esters will have too strong of an odor, which is a problem when using them, and will be extremely difficult to tolerate in practice, making them unsuitable as cleaning agents. On the other hand, when fatty acid esters are lacking, the degreasing ability decreases.

Therefore, a practical cleaning agent can only be obtained by using both at the same time.

Furthermore, it is possible to add various stabilizers and additives to the composition of the present invention in order to maintain the stability of the liquid and improve the stability against the objects to be washed, or to improve the dissolving power. Examples of stabilizers and additives include hydrocarbons, ethers, acetals, ketones, nitroalkanes, amines, benzotriazoles, and the like.

〔Example〕

Hereinafter, the present invention will be specifically explained using Examples and Comparative Examples. The cleaning method is as follows.

Cleaning method - ■ As shown in Figure 1, a capacity 1000 d unit equipped with a cooling pipe.
3 hard glass cleaners (1st tank, 2nd tank, 3rd tank)
The composition of the present invention or the comparative solvent 3007 was prepared for each type.
Put nl, the first tank is a boiling tank, and the second tank is a cold bath (room temperature)
, the third tank was used as a steam tank.

■ Apply various types of flux (manufactured by Tamura Seisakusho, product name: Flux F-2) to the item to be washed (glass epoxy printed circuit board).
30V and MH-320V) and melted solder bath (
Soldering was carried out at 260°C for 5 seconds.

(2) Each of the items to be washed was immersed in order for 1 minute (however, in the third tank, the items to be washed were simply put into the steam layer).

■ Thereafter, the ion content remaining on the printed circuit board was measured using an omega meter.

Examples 1-7 A cleaning experiment was conducted on the compositions shown in Table 1.

The results are shown in Table 3.

Comparative Examples I-6 Cleaning experiments were conducted using the solvents shown in Table 2.

The results are shown in Table 3.

The following margin is Table 1 [Effects of the Invention] The composition of the present invention has good cleaning performance and finish quality comparable to conventional fluorocarbon-based and chlorinated solvents, and moreover,
Does not destroy ozone. Furthermore, the composition of the present invention can be easily recovered by boiling or distillation using the washing machines and distillers used for conventional fluorocarbon and chlorine solvents, so the conventional equipment can be used almost as is. You can.

Furthermore, since the composition of the present invention has a low boiling point, it is easy to dry the items to be washed, so there is no need for steps such as water rinsing to remove the cleaning agent from the items to be washed during the work process. . Therefore, there is no fear that the water environment will be contaminated by wastewater.

Therefore, the composition of the present invention is practically an excellent flux cleaning agent that can replace conventional fluorocarbon-based and chlorinated solvents.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a method of cleaning objects to be washed using cleaning agents of Examples and Comparative Examples. To print the ion content residue of the second tank and the third tank.

Claims (2)

[Claims] 1. (1) One or more alcohols having 3 to 4 carbon atoms, and (2) A flux cleaning agent characterized by containing fatty acid esters as an essential component.