JPS6233016Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface treatment apparatus containing a chemical treatment solution, such as an etching treatment apparatus.

Etching processing technology is applied to various fields such as microfabrication of semiconductor devices such as solar cells, wiring formation of printed circuit boards, electrode formation of display cells, etc. For example, in the etching process of solar cells, surface treatment The etching solution used is a high temperature alkaline solution. That is, an alkaline etching solution such as a caustic soda solution is stored in an etching tank, and this etching solution is maintained at a high temperature.
A solar cell element that has undergone pretreatment such as surface cleaning, drying, and mask formation is immersed in an etching solution and held for a predetermined time while shaking the etching solution or the solar cell element, and then the solar cell element is pulled out of the etching bath. As a result, the solar cell element is etched. However, in this etching process, the etching solution is kept at a high temperature, so there is a problem that the etching solution evaporates rapidly from the etching bath, requiring a large amount of etching solution. This results in a lot of thermal energy being consumed for retention.

As a technique for preventing evaporation from the liquid surface of an open tank containing a volatile liquid, a method is known in which spheres are suspended densely on the liquid surface, as shown in Japanese Patent Publication No. 28401/1983. In this method, a circumferential edge for preventing rotation is formed on a hollow sphere, and a large number of these hollow spheres are suspended in a volatile liquid, and a volatile liquid 2 stored in an open tank 1 is suspended as shown in a plan view in FIG. By covering the surface with the hollow spheres 3, evaporation from the surface of the liquid 2 is prevented, and the liquid surface is prevented from freezing or has a heat retaining effect. However, even in this method, a larger amount of liquid actually evaporates than the space between the hollow spheres floating in the liquid, and a sufficient heat retention effect cannot be achieved. It is thought that the most effective effect can be obtained if the circumference of the maximum diameter of the hollow sphere approximately matches the liquid level, but it is not possible to create a large number of hollow spheres in such a way that they are suspended. requires precision machining and is extremely difficult. Furthermore, it is not possible to maintain a constant floating level for liquids whose specific gravity changes by heating them. For the above reasons, even if the above method is applied to a surface treatment apparatus such as an etching treatment apparatus, it is insufficient to prevent evaporation of a chemical solution and to achieve a heat retaining effect.

In view of the above-mentioned current situation, the present invention is a new and useful surface treatment device that can significantly suppress the evaporation of surface treatment solutions and significantly reduce the consumption of thermal energy for maintaining high temperatures by making full use of technical means. The purpose is to provide the following.

Hereinafter, the present invention will be explained in detail according to embodiments with reference to the drawings.

FIG. 2 is a perspective view of essential parts of an etching processing apparatus showing one embodiment of the present invention.

Etching liquid 5 is stored in tank 4, and is heated by an external heater (not shown). On the surface of the etching liquid 5, cubic seal blocks 6 made of a lightweight material that is stable against chemicals such as tetrafluoroethylene are densely arranged. Further, in the tank 4, a stirring blade (not shown) suspended from the tip support leg 8 of a swing rod 7 connected to a drive source is swingably disposed within the etching liquid 5.
As the rocking rod 7 moves up and down as shown by arrows in the figure, the stirring blades are interlocked and the etching liquid 5 is stirred.

FIG. 3 is a plan view of the etching processing apparatus of FIG. 2 with the swing rod 7 removed. FIG. 4 is a perspective view showing the detailed shape of the seal block 6.

The etching liquid 5 is heated and maintained at the etching temperature, and the solar cell element to be etched is immersed in the etching liquid 5. Next, the swinging rod 7 is hung down to place the stirring blade in the etching liquid 5, and the seal block 6 is densely suspended on the surface of the etching liquid 5, leaving the vicinity of the support leg 8, without any gaps. After etching the solar cell element for a predetermined time while stirring the etching liquid 5 by driving the rocking rod 7, the solar cell element is taken out from the bath 4 to perform the etching process.

In addition, without using a stirring blade, a mounting table is attached to the support leg 8 of the rocking rod 7, and the solar cell element to be etched is placed directly on this mounting table, and the mounting table is placed in the etching solution 5. It may also be configured to swing up and down. Further, in the etching process which does not require stirring or the like, the entire liquid surface is coated with a seal block 6 as shown in FIG.

The seal block 6 is made of a material whose specific gravity is lighter than that of the etching liquid 5, and a large number of identical floating bodies can be manufactured by simply aligning the shapes and dimensions without requiring precision machining. In addition, when these are arranged in a floating manner, there are almost no gaps, and almost the entire surface of the etching liquid 5 can be covered, so that evaporation of the etching liquid 5 is greatly suppressed. By making only one specific surface of the seal block 6 heavy, the same surface can always be placed above the liquid surface.

The shape of the seal block 6 is not limited to a hexagonal shape, but can be a regular tetrahedron, a square prism, a regular prism, and various other shapes as shown in FIGS. 5A, B, and C.

As explained in detail above, the present invention can be used in etching processing equipment, electrolytic polishing equipment, chemical cleaning equipment, and other surface treatment equipment that uses various chemical solutions by arranging polyhedrons densely on the surface of the chemical solution.
The liquid surface can be sealed with almost no gaps, and this sealed state is maintained even if the specific gravity changes as the solution temperature rises and the length of the seal block 6 above the liquid surface (floating level) changes. As a result, the evaporation of the solution is significantly suppressed and the energy consumption during high temperature maintenance is significantly reduced. It can also be used to prevent solution scattering and moisture intrusion. Furthermore, there is no need to remove the seal block when inserting and removing the etching treatment member into the tank, and surface treatment can be performed continuously while the etching member is always suspended on the liquid surface, making it an optimal technology for automation.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram illustrating a conventional volatile liquid sealing method. FIG. 2 is a perspective view of essential parts of an etching processing apparatus showing one embodiment of the present invention. Third
The figure is a plan view of the etching processing apparatus shown in FIG. 2. FIG. 4 is a perspective view of the seal block. FIG. 5 is a perspective view showing another embodiment of the seal block. 4...tank, 5...etching liquid, 6...seal block.

Claims (1)

[Scope of utility model registration request] a tank in which a chemical solution for surface treatment is stored; a plurality of polyhedral blocks suspended in the chemical solution in the tank and keeping the surface of the chemical solution in a substantially sealed state;
2. A surface treatment apparatus comprising: a polyhedral block, wherein adjacent polyhedral blocks are connected to each other on at least one face of the polyhedron.