JPH0440270A - Cleaning method for electronic component - Google Patents

Abstract

PURPOSE:To prevent the oxidation and corrosion of an electronic component in a cleaning process by reducing the concn. of dissolved oxygen in cleaning water to about 1ppm or less. CONSTITUTION:A membrane type deoxygenating device 1 is inserted in a cleaning water supply line 4 to remove dissolved oxygen in the cleaning water supplied to a cleaning tank 3 for an electronic component to reduce the concn. of dissolved coxygen to about 1ppm or less. Raw water is purified by a pure water apparatus S, for example, a reverse osmosis membrane apparatus to store pure water in a tank 7 and this pure water is fed to the membrane type deoxygenating device 1 by a pump 7. The cleaning water from which dissolved oxygen is removed by the membrane type deoxygenating apparatus is sent to the cleaning tank 3 but, as the cleaning tank 3, a hermetically closed one is used in order to prevent the re-dissolution of oxygen and, for example, the tank is filled with inert gas, for example, N2 to prevent the mixing with oxygen in an atmosphere from the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for cleaning IC boards, solar cells, other electronic components, etc.

[Conventional technology and its problems]

As is well known, fluorocarbons or pure water are generally used to clean electronic parts, but the use of fluorocarbons is being banned worldwide to protect the global environment. On the other hand, when using pure water, there are problems with oxidation and corrosion of electronic components due to the influence of dissolved oxygen.
We try to use inhibitors, so-called corrosion inhibitors, but using inhibitors requires large-scale processing equipment to prevent pollution, and there are other problems such as the inhibitors adhering to products and metal ions leaking into the cleaning solution. There is.

[Means for Solving the Problems] In view of the above-mentioned problems, the present invention aims to provide a safe and low-cost cleaning method. The method is characterized in that deoxygenated water with a dissolved oxygen concentration of about 1 ppm or less is produced by vacuum degassing through an oxygen-depleting membrane, and this water is continuously supplied to a tank for cleaning electronic parts.

[Function] According to the above configuration, by using deoxygenated water with a dissolved oxygen concentration of 1 ppm or less by a membrane-type oxygen absorbing device as cleaning water for electronic parts, it is safe without any risk of pollution, and moreover, it is easy to clean on a large scale. Electronic components can be cleaned using a simple and low-cost system that does not require special equipment.

〔Example〕

Preferred embodiments of the present invention will be described below with reference to the drawings.

In the figure (1) is a membrane type oxygen deoxidizer, and the washing water supply line (4
) to remove dissolved oxygen in the cleaning water supplied to the cleaning tank (3) for electronic parts, etc. (dissolved oxygen concentration approximately 1p).
Pln and below). (5) is a water purifier that purifies raw water using, for example, a reverse osmosis membrane device, stores it in a tank (6), and sends it to the next membrane-type oxygen absorber (1) using a pump (7). do.

The cleaning water from which dissolved oxygen has been removed by this membrane-type deoxidizer is sent to the cleaning tank (3), but this cleaning tank is of a closed type to prevent oxygen from re-dissolving; for example, N2
The tank is filled with inert gas such as (
Prevents oxygen from entering the atmosphere (in the atmosphere).

In the embodiment shown in FIG. 2, a circulation line (8) is provided in the cleaning tank (3), and a circulation pump (9) and a membrane type oxygen deoxidizer (1) are inserted into this circulation line, so that the inside of the cleaning tank is The amount of dissolved oxygen in the cleaning water is always kept below a certain value.

Figure 3 shows an example of an abdominal deaerator (1). In the same figure, (2) is a deoxidizing membrane using a hollow fiber gas permeable membrane, and the outer periphery of the deoxidizing membrane is sealed with water. A vacuum state is created using a vacuum pump 00), and dissolved gases in the raw water flowing through the membrane are removed through the protective membrane.

θD is a pressure reducing valve, surface is a constant flow valve, and 03) and Q4) are solenoid valves. 05) is a flow switch, and this switch uses its output signal to control the water ring type vacuum pump 0.
0) and the opening and closing of solenoid valves 03) and 04) (i.e., when raw water flows through the device, the flow switch is activated, turns on the vacuum pump, and turns on the two solenoid valves 03) and 04). The solenoid valve becomes open.

〔Effect of the invention〕

The present invention has the above configuration, and by controlling the dissolved oxygen concentration in the cleaning water to about 1 ppm or less, it is possible to prevent oxidation and corrosion of electronic components during the cleaning process. Since no corrosion inhibitor is used, the trouble of managing the corrosion inhibitor is omitted, providing a safe and low-cost cleaning method, and there is no need to worry about the corrosion inhibitor adhering to the product or metal ions leaking into the cleaning solution. Moreover, by using a membrane-type oxygen absorber, the system configuration is simple and low cost.
Continuous processing is possible at room temperature.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing one embodiment of the present invention, Fig. 2 is a system diagram showing another embodiment of the invention, and Fig. 3 is a system diagram showing an embodiment of the membrane type oxygen removing device in this invention. It is a diagram. (])...Membrane peritoneal oxygen device (2)...Oxygen removal membrane (3)...Washing tank Fig. 1 j112

Claims (1)

[Claims] The raw water is introduced into the membrane type oxygen absorber (1), and the oxygen absorbing membrane (2
) to obtain deoxygenated water with a dissolved oxygen concentration of approximately 1 ppm or less, and continuously supplying this to an electronic component cleaning tank (3). .