JPH02218481A - Washing method - Google Patents

Abstract

PURPOSE:To achieve high washing effect within a short time by applying shower washing to an object to be washed in the washing solution in a liquid tank by a washing nozzle by forming an air layer at the boundary surface of the shower solution injected from the first nozzle and the washing solution in the liquid tank. CONSTITUTION:Washing nozzles 11, 12 are equipped with the first nozzles 25, 26 injecting a shower solution and the second nozzles 27, 28 injecting air from the outer peripheries of the first nozzles and, when the shower solution is injected from the first nozzles, air is allowed to flow out from the second nozzles to form an air layer around the shower solution injected from the first nozzles. Then, an object 3 to be washed is immersed in the washing solution stored in a liquid tank 3 and an air layer is formed in the washing solution in the liquid tank 2 at the boundary surface of the shower solution injected from the first nozzles and the washing solution in the liquid tank 2 by the washing nozzles 11, 12 to apply shower washing to the object 3 to be washed. As a result, high washing effect can be achieved within a short time without enlarging the washing apparatus.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a cleaning method for shower cleaning objects to be cleaned, and in particular, to electronic components contaminated with deposits such as water-soluble flux and solder balls. The present invention relates to a cleaning method suitable for cleaning IC parts, etc.

[Prior Art] Conventionally, as a cleaning method for cleaning contaminated electronic components and IC components as described above, electronic components and IC components are cleaned in the atmosphere using a cleaning device equipped with a cleaning nozzle. There is a method of shower cleaning by spraying cleaning liquid onto the object to be cleaned.

For example, as shown in FIG. 6, this cleaning device has three cleaning tanks 102a and 102b inside separated by a partition wall 101.
, 102C, each cleaning tank 1
Washing nozzles 103, 104, and 105 are provided above the objects 02a, 102b, and 102c to perform shower cleaning by spraying a cleaning liquid onto an object to be cleaned (not shown).

The items to be cleaned are stored in the magazine 106 and the compare 10
7.

A cleaning liquid is stored inside each cleaning tank 102a, 102b, 102c.
Heaters 108 and 109 provided in 02b and 102C
．． 110.

Each cleaning tank 102a, 102b, 102C and each cleaning nozzle 103.104.105 are water pipes 114.11 each equipped with a 'fR view control valve 111.112.113.
5.116, each cleaning tank 102a
, 102b, 102C from inside the pump 11γ, 118.1
The cleaning liquid pumped up by the filter 120
．． 121.122 through each cleaning nozzle 103.10
4.105.

In addition, each water pipe 114, 115, 116 has a pump 1.
Directly from the downstream of 1γ, 118 and 119, each cleaning tank 102
Bypass pipe 123 communicating with a, 102b, and 102C
．． 124 and 125 are connected, each bypass pipe 12
3.124.125, bypass pipe 123 respectively.
．． Opening/closing valve 126.127 to open/close 124.125
．． 128 are provided.

The items to be cleaned stored in the magazine 106 are transported to the conveyor 10.
7 to the upper part of each cleaning tank 102a, 102b, 102C in order, and each cleaning nozzle 103.104.1
Shower cleaning by 05.

[Problems to be Solved by the Invention] However, the cleaning method using the above-mentioned cleaning device performs shower cleaning in the atmosphere, and although it is effective in cleaning the parts that are directly exposed to the shower liquid, it is not effective for cleaning the IC chip. Items to be cleaned such as mounted printed circuit boards and electronic circuit boards assembled with circuit components such as resistors and capacitors must be
It is less effective in cleaning areas that are blocked by the C-chip and various circuit components and are not directly exposed to shower liquid.9 Therefore, in order to increase the cleaning effect, the cleaning time must be lengthened or the shower cleaning process must be done in a separate process. Since immersion cleaning using ultrasonic waves or rocking is required, the cleaning equipment becomes larger and more complex, resulting in higher costs.

It is also possible to immerse the object to be cleaned in a cleaning liquid and perform shower cleaning in the cleaning liquid, but in this case,
Due to the occurrence of cavitation and the diffusion of the shower liquid due to boundary friction between the shower liquid sprayed from the nozzle and the cleaning liquid in the liquid tank, the straightness of the shower liquid decreases and the impact force is halved. Therefore, it is not possible to obtain a cleaning effect similar to shower cleaning in the atmosphere.

The present invention has been made based on the above circumstances, and its purpose is to provide a cleaning method that can obtain high cleaning effects in a short cleaning time without increasing the size of the cleaning device. be.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a first nozzle through which shower liquid is injected, and a second nozzle through which gas flows out from the outer periphery of the first nozzle. a cleaning nozzle that forms a layer of gas around the outer periphery of the shower liquid injected from the first nozzle by causing gas to flow out from the second nozzle when the shower liquid is injected from the first nozzle; The object to be cleaned is immersed in a cleaning liquid stored in a liquid tank, and the cleaning nozzle separates the shower liquid sprayed from the first nozzle and the cleaning liquid in the liquid tank into the cleaning liquid in the liquid tank. As a technical means, the object to be cleaned is shower-cleaned by forming a gas layer on the boundary surface of the cleaning object.

[Operations and Effects of the Invention] According to the present invention, a gas layer is formed in the cleaning liquid in the liquid tank at the interface between the shower liquid injected from the cleaning nozzle and the cleaning liquid in the liquid tank. Attenuation of the shower liquid due to cavitation and diffusion of the shower liquid due to boundary friction between the shower liquid and the cleaning liquid in the liquid tank can be reduced. Therefore, powerful and straight-moving shower cleaning can be performed even with the cleaning liquid in the liquid tank.

In addition, by performing powerful shower cleaning, a mixture of the cleaning liquid and air bubbles is formed on the surface of the object to be cleaned, so that the vicinity of the surface of the object to be cleaned is agitated.

In this way, by immersing the object to be cleaned in the cleaning liquid in the liquid tank and performing a powerful shower cleaning, it goes without saying that the cleaning effect of the parts that are directly hit by the shower liquid is high, but it is also possible to wash the parts that are directly hit by the shower liquid. You can also clean areas that are not covered.

Therefore, according to the cleaning method of the present invention, a high cleaning effect can be obtained, so that the cleaning time can be shortened compared to the conventional method. In addition, the cleaning process and the number of cleaning tanks formed in the liquid tank can be reduced, and since shower cleaning is performed in the cleaning liquid, there is no scattering of the shower liquid, and the cleaning device has a small and simple configuration. can be provided.

[Example] Next, the cleaning method of the present invention will be explained based on an example shown in the drawings.

FIG. 1 is an overall schematic diagram of a cleaning device employing the cleaning method of the present invention, and FIG. 2 is a sectional view of a cleaning nozzle.

The cleaning device 1 of this embodiment cleans the cleaning liquid (water in this embodiment) stored in a liquid tank 2 by cleaning an object 3 (a fourth (see Figures 1 and 5).

In order to store the heated cleaning liquid, the liquid tank 2 has an outer frame formed from a heat insulating material 2a from the bottom to a predetermined height, and the upper open end of the liquid tank 2 is covered with a lid 2b. ing.

The interior of the liquid phase 2 is divided into two cleaning tanks 5 and 6 by a partition wall 4.
At the bottom of each cleaning tank 5.6, there is a cleaning tank 5.6.
A heater 7.8 is installed for heating the cleaning liquid stored therein.

A conveyor 10 is built into the liquid tank 2 for storing the objects 3 to be cleaned in a magazine 9 and conveying them.

As shown in FIG. 1, the conveyor 10 enters the liquid tank 2 from outside the liquid tank 2 through an opening 2C formed in a side wall of the liquid tank 2, and enters the cleaning tank 5. This is a circulation path that passes through the inside of the liquid tank 6 and the inside of the cleaning tank 6, and then reaches the outside of the liquid tank 2 again from the opening 2C.

A cleaning nozzle 11 is provided on the side wall of the liquid tank 2 for shower cleaning the object 3 in the cleaning liquid in each cleaning tank 5.6.
．． 12 are attached to each.

The cleaning nozzle 11.12 is provided approximately at the center of the cleaning tank 5.6 so that the nozzle tip faces upward.

Each cleaning nozzle 11.12 has a flow rate control valve 13.
．． Cleaning tank 5.6 by water pipe 15.16 with 14
The cleaning tank 5 is connected to the water pipes 15 and 16.
．． A pump 17.18 for supplying cleaning liquid from inside the cleaning nozzle 11.12 to the cleaning nozzle 11.12, and a filter 19.20 for passing through the cleaning liquid supplied by the pump 17.18 are provided.

The water distribution pipe 15.16 also includes a bypass pipe 21.2 which directly communicates with the washing tank 5.6 from downstream of the pump 17.18.
2 is connected, and this bypass pipe 21.22 is provided with an on-off valve 23.24.

Therefore, the pressure and flow rate of the shower liquid (cleaning liquid) sprayed from the cleaning nozzles 11 and 12 can be adjusted by using the water pipe 15.
．． This is done by a flow ffi control valve 13.14 provided in the bypass pipe 21.22 and an on-off valve 23.24 provided in the bypass pipe 21.22.

As shown in FIG. 2, the cleaning nozzle 11.12 of this embodiment includes a first nozzle 25.26 and a first nozzle 25.2.
The first nozzle 25 has a predetermined space around the tip end of the first nozzle 25.
．． The second nozzle 27. is fitted to the outer peripheral portion of the tip of the second nozzle 27.
It consists of 28.

The first nozzle 251.26 and the second nozzle 27.28 are
To screw together the male threaded portions 25a, 2f3a formed on the outer circumferential portion of the rear end of the first nozzle 25.26 and the female threaded portions 27a, 28a formed on the inner circumferential portion of the rear end of the second nozzle 27.28. The first nozzle 25.26 and the second nozzle 27.28 are positioned relative to each other by a lock nut 29.30.

The first nozzle 25.26 is connected to the water pipe 15.16 and has a first injection port 25b formed at the tip (left end in FIG. 2).
, 26b spray the shower liquid.

The second nozzle 27.28 has a tip end connected to the first nozzle 25.28.
The second injection port 27 is set concentrically with the first injection port 26.
b, 28b are formed, and air pockets 27c, 28b, which are the predetermined spaces described above, are formed on the outer peripheral side wall near the tip.
A through hole 27d-286 is formed which communicates with the hole 8c. Pressurized air is supplied from the outside to the through holes 27d and 28d, and is guided to the air pockets 27c and 28C. Note that the first nozzle 25.2G and the second nozzle 27.28 are fitted together via an O-ring 31.32, and the pressurized air guided to the air pockets 27c and 28c is
There is no leakage from the joint between the nozzle 25.26 and the second nozzle 27.28.

The second injection holes 27b and 28b of the second nozzles 27 and 28 are
It is formed at a position that is tapered and depressed from the tip surface, and the distance between it and the first injection ports 25b and 26b is narrowed.

This cleaning nozzle 11.12 has first injection ports 25b, 2
The outflow pressure of the shower liquid injected from 6b is set to be higher than the pressure of the pressurized air guided to the air reservoirs 27c and 28c. For this reason, the first injection port 25
The shower liquid injected from b and 26b and the pressurized air supplied to the air pockets 27c and 28c are injected from the second injection port 2γ as well while the pressurized air is drawn around the outer periphery of the shower liquid. Ru.

Therefore, in the cleaning liquid in the cleaning tank 5.6, as shown in FIG. , an air layer C is formed by pressurized air.

Next, the operation of this embodiment will be explained.

The magazine 9 containing the objects 3 to be cleaned is mounted on the conveyor 10 and carried into the liquid tank 2 through the opening 2C.

First, rough cleaning is performed by submerged shower cleaning and immersion cleaning at the upper position of the cleaning nozzle 11.12 in the cleaning tank 5.6. Next, the cleaning nozzle 11. in the cleaning tank 5.6.
At the upper position of No. 12, final cleaning is performed by submerged shower cleaning and immersion cleaning similar to that in the cleaning tank 5.6.

As a result, for example, as shown in FIGS. 4 and 5,
Deposits (water-soluble flux, solder balls, etc.) 33 are
Even if the object 3 to be cleaned is covered with the IC chip 3a or circuit components 3b such as resistors and capacitors, the deposits 33 can be removed by powerful shower cleaning, and the residue can be removed by immersion cleaning. Supplementary cleaning can be performed, and deposits 34 attached to the back surface of the substrate can be removed.

Generally, when shower cleaning is performed in a liquid, the force of the shower liquid is attenuated, so that the cleaning effect is lower than that of shower cleaning in the atmosphere.

On the other hand, in the case of this embodiment, an air layer is formed around the outer periphery of the shower liquid sprayed from the cleaning nozzle 11.12 in the cleaning liquid in the cleaning tank 5.6, thereby preventing cavitation. Since it is possible to reduce the attenuation of the shower liquid due to generation and the diffusion of the shower liquid due to the narrowing of the boundary between the shower liquid and the cleaning liquid in the cleaning tank 5.6, it is possible to perform powerful and straight shower cleaning. . Further, due to the strong shower cleaning, a mixture of the cleaning liquid and air bubbles is formed on the surface of the object 3 to be cleaned, so that the vicinity of the surface of the object 3 to be cleaned is agitated.

In this way, efficient and high cleaning effects can be obtained by powerful shower cleaning and immersion cleaning in the cleaning liquid.

Therefore, according to the cleaning method of the present invention, it is possible to perform effective cleaning with a shorter cleaning time than in the past.

In addition, since the cleaning effect is high, cleaning process and cleaning tank 5.
6 can be reduced, and since the shower cleaning is performed in the cleaning liquid, there is no scattering of the shower liquid. As a result, the cleaning device 1 can be downsized with a simple configuration, and costs can be reduced.

(Modified Example) In this embodiment, water is used as the cleaning liquid, but there is no need to limit it to water, and other liquids such as alkaline liquid and alcoholic liquid may be used.

Similarly, although pressurized air was supplied to form an air layer around the shower liquid, other gases such as nitrogen gas or helium gas may be used.

When you want to expand the cleaning range or improve the cleaning effect, you can swing the cleaning nozzle 11.12 or the object to be cleaned 3, or increase the number of cleaning nozzles 11.12 to achieve high density cleaning. It may also be used as a nozzle.

[Brief explanation of the drawing]

1 to 5 show an embodiment of the present invention,
Figure 1 is an overall schematic diagram of the cleaning device, Figure 2 is a sectional view of the cleaning nozzle, Figure 3 is a state diagram of the shower liquid sprayed from the cleaning nozzle, and Figures 4 and 5 are the objects to be cleaned. FIG. 6 is an overall schematic diagram showing an example of a conventional cleaning device. In the figure 2...Liquid tank 3...Object to be cleaned 11. 12...Cleaning nozzle 25.26...1st nozzle 27.28...2nd nozzle agent Kenji Ishiguro 4th diagram Figure 5

Claims (1)

[Claims] 1) a first nozzle through which shower liquid is sprayed;
It has a second nozzle through which gas flows out from the outer periphery of the nozzle,
a cleaning nozzle that forms a layer of gas around the outer periphery of the shower liquid injected from the first nozzle by causing gas to flow out from the second nozzle when the shower liquid is injected from the first nozzle; The object to be cleaned is immersed in a cleaning liquid stored in a liquid tank, and the cleaning nozzle separates the shower liquid sprayed from the first nozzle and the cleaning liquid in the liquid tank into the cleaning liquid in the liquid tank. A cleaning method characterized in that the object to be cleaned is shower-cleaned by forming a gas layer on the boundary surface of the object.