TWM653056U - Sealing gasket - Google Patents

Abstract

This invention is mainly about a sealing gasket, which includes two structural layers of different materials that are layered together. The material of the second structural layer is expanded polytetrafluoroethylene (ePTFE). Since expanded polytetrafluoroethylene itself has chemical resistance, pressure resistance and high temperature resistance, and its cost is very low, it can be used to improve the product life. However, the elasticity of the second structural layer is relatively low. Therefore, the second structural layer is polymerized and co-constructed with the first structural layer with higher elasticity and lower cost, which can achieve the multiplier effect of improving the structural quality and can significantly reduce the cost to improve the product competitiveness.

Description

Sealing gasket

This practical creation involves the technical field of sealing gaskets, especially sealing gaskets with layered structures.

According to the semiconductor plasma process, chemical vapor deposition (CVD) is a chemical technology used to produce high-purity and high-performance solid materials. The semiconductor industry uses this technology to grow thin films. The typical chemical vapor deposition process is to expose the wafer substrate to one or more different precursors, and chemical reactions or chemical decompositions occur on the substrate surface to produce the film to be deposited. The plasma is also called plasma. It is the fourth state of matter after solid, liquid and gas, and its properties are completely different from the first three. Gas will become plasma under high temperature or strong electromagnetic field. Plasma is an ionized gas with equal amounts of positive and negative charges. It is composed of ions, electrons and neutral atoms or molecules. Scientists call plasma the fourth state of matter. Scientists estimate that nearly 99% of matter in the universe exists in the plasma state. Plasma is generated by using external energy to cause electrons in the gas to gain energy and accelerate to collide with neutral atoms. When neutral atoms are hit by accelerated electrons, they will produce ions and another accelerated electron with energy. These released electrons are accelerated by the electric field and collide with other neutral atoms. This is repeated over and over again, causing the gas to collapse (gas breakdown) and form a plasma state.

Please refer to Figure 1, which shows a conventional sealing ring inside the plasma pressure reaction chamber. Action diagram, in which the sealing ring 6 is tightly sealed in a reaction chamber 4. The outside is a hardware device with an upper seat 2 and a lower seat 1. One side of the reaction chamber 4 has a gap 3. When the semiconductor When the plasma process is in progress, the plasma pressure P will enter the gap 3, and then enter the reaction chamber 4 through the gap 3, so that the first side of the sealing ring 6 faces the impact of the plasma pressure P, and the back side is forced to against the position of the relative isolation area 5; please refer to Figure 2. When the plasma pressure P increases in intensity and enters the reaction chamber 4 from the gap 3 to exert pressure on the surface of the sealing ring 6, the surface of the sealing ring 6 will be affected. The impact pressure of the plasma pressure P causes damage, causing dust to be generated on the surface of the sealing ring. The dust then flows around through air disturbance, causing the dust to contaminate the reaction chamber, thereby reducing the yield of the semiconductor wafer process.

In view of this, the conventional solution is to use sealing rings made of perfluoroelastomer (FFKM) to solve the above problems. Because sealing rings made of perfluoroelastomer have the best temperature and chemical resistance, they can withstand high temperature operations. The environment is 260~290 degrees Celsius. Special models can maintain sealing ability in an environment of 316 degrees Celsius. The instantaneous high temperature can reach 330 degrees Celsius. At the same time, it can withstand strong acids, strong alkali, ethers, ketones, esters, including Corrosion from various chemical products such as nitrogen compounds, hydrocarbons, alcohols, aldehydes, oils, steam, amine compounds, etc. However, the cost of sealing rings made of perfluoroelastomer is very expensive, which can easily reduce the competitiveness of the product. .

That is, the main purpose of this invention is to provide a sealing gasket; the problem it wants to solve is to overcome the problem that the cost of the conventional sealing gasket made of perfluoro rubber (FFKM) material is high, which easily reduces the competitiveness of the product; thus, the sealing gasket of this invention combines two structural layers of different materials through a layered structure, and the material of the second structural layer is expanded polytetrafluoroethylene ( Polytetrafluoroethylene (ePTFE), because expanded polytetrafluoroethylene itself has chemical resistance, pressure resistance and high temperature resistance, and the cost is very low, but the second structural layer is not elastic, so the second structural layer is polymerized and co-constructed with the first structural layer, which is elastic and low-cost, to achieve the multiplier effect of improving the structural quality and significantly reduce costs to improve product competitiveness.

Common knowledge part:

1: Take a seat

2: Take your seat

3: Gap

4: Reaction chamber

5:Isolation zone

6:Sealing ring

7: Dust

P: Plasma pressure

This creative part:

1: Take a seat

2: The seat of honor

3: Gap

4: Reaction chamber

5: Isolation zone

O:Sealing ring

10: First structural layer

11: First bonding surface

12: External surface

20:Second structural layer

21:Inner surface

22:Second joint surface

P: Plasma pressure

Figure 1: Schematic diagram of the operation of a conventional sealing gasket inside the plasma pressure reaction chamber.

Figure 2: This is the second diagram showing the operation of the sealing gasket inside the plasma pressure reaction chamber.

Figure 3: A partial cross-sectional perspective view of a sealing gasket created by this invention.

Figure 4: An enlarged view of Part A of Figure 3.

Figure 5: Transverse cross-sectional view of a sealing gasket created by this invention.

Figure 6: This is the first diagram of the sealing gasket in the plasma pressure reaction chamber.

Figure 7: Diagram 2 of the schematic operation of a sealing gasket created by this invention inside the plasma pressure reaction chamber.

Please refer to Figures 3 to 7, which are preferred embodiments of a sealing gasket of this invention. However, these embodiments are for illustrative purposes only and are not limited to this structure in patent applications.

The sealing gasket includes a sealing ring O, including two structural layers of different materials. The two structural layers are polymerized and co-constructed into one body, including a first structural layer 10 and a second structural layer 20. In this embodiment, the third structural layer The material of the second structural layer 20 is expanded polytetrafluoroethylene (ePTFE), and the material of the first structural layer 10 is nitrile rubber (NBR) or butadiene rubber (BR) or other materials with similar elastic properties. Rubber; wherein the first structural layer 10 is located on the annular outer side of the sealing ring O, has an arc-shaped outer surface 12 relative to the outer edge of the sealing ring O, and forms a first bonding surface relative to the end surface of the second structural layer 20 11. In addition, the second structural layer 20 is located on the annular inner side of the sealing ring O, opposite to the inside of the sealing ring O. The edge has a planar inner surface 21, and the second structural layer 20 forms a second bonding surface 22 relative to the inner edge of the sealing ring O, wherein the first bonding surface 11 of the first structural layer 10 and the second structure The polymerization and co-construction technology of the second bonding surface 22 of the layer 20 is through integrated double injection molding.

The dual-material injection molding is an injection molding technology. The principle is to load two different plastic raw materials into the injection cylinder of an injection machine, and inject the two different plastic raw materials into the mold simultaneously or alternately through the injection system of the injection machine to form a sealing ring O with two different materials polymerized. Since this technology is a known injection molding method, it will not be described in detail.

Then, the expanded polytetrafluoroethylene material of the second structural layer 20 can withstand high temperatures up to 316 degrees Celsius, and has better corrosion resistance than perfluororubber material. The expanded polytetrafluoroethylene material is a microporous membrane formed by expanding and stretching polytetrafluoroethylene as a raw material. The surface of the expanded polytetrafluoroethylene material is full of original fiber-like micropores, and each square inch has a network of up to 9 billion micropore cross-sections. The three-dimensional structure The structure has complex mesh interconnecting channels and curved channels that are interlaced and formed. The expanded polytetrafluoroethylene material of the second structural layer 20 is almost not corroded by any chemical reagents except molten alkaline metals. For example, its weight and performance remain unchanged when boiled in concentrated sulfuric acid, nitric acid, hydrochloric acid, or even in aqua regia. The expanded polytetrafluoroethylene material does not absorb moisture, is non-flammable, is extremely stable to oxygen and ultraviolet rays, and has very strong chemical resistance.

Furthermore, the sealing ring O of this invention is mainly used in the plasma process of semiconductors. In the semiconductor process environment, the transistors on the chip must be very pure. If there are impurities attached to the transistors, it is easy to cause the chip to be short. Therefore, the chip must be in an ultra-vacuum state during the production process. Therefore, the sealing ring O of this invention with the second structural layer 20 of expanded polytetrafluoroethylene material can ensure that no air or liquid can pass between the two connected parts to achieve a true sealing state.

Please refer to Figure 6, which is a schematic diagram of the sealing ring O of the invention in the plasma pressure P reaction chamber 4, wherein the sealing ring O is tightly sealed in a reaction chamber 4, and the outside is a hardware device with an upper seat 2 and a lower seat 1 combined. One side of the reaction chamber 4 has a gap 3. When the semiconductor plasma process is in progress, the plasma pressure P will enter the gap 3 and then enter the reaction chamber 4 from the gap 3, so that the second structural layer 20 faces the impact of the plasma pressure P, and the first structural layer 10 is pressed against the relative isolation area 5.

As shown in FIG. 7 , when the plasma pressure P increases in strength and enters the reaction chamber 4 through the gap 3 to apply pressure to the surface of the second structural layer 20, the second structural layer 20 is made of a very soft expanded polytetrafluoroethylene material and the surface of the second structural layer 20 is covered with fibrous micropores. Therefore, even when the second structural layer 20 is subjected to a large pressure, it will directly fill the entire reaction chamber 4. Gap 3. Furthermore, because the expanded polytetrafluoroethylene material of the second structural layer 20 has high chemical resistance, pressure resistance and high temperature resistance, when the second structural layer 20 faces a strong plasma pressure P, it will not generate dust due to surface damage to improve the yield of the semiconductor chip process.

It is worth mentioning that the second structural layer 20 made of expanded polytetrafluoroethylene does not necessarily need to be located inside the annular shape of the sealing ring O. Depending on the use requirements, the second structural layer 20 can be disposed on the sealing ring O instead. The annular outer side, or the top or bottom side of the sealing ring in the axial direction, is arranged inside and outside or up and down with the first structural layer 10, so that the sealing ring O combines two structural layers of different materials in a layered distribution.

In this way, the sealing ring O of this invention combines two ring layers of different materials in a layered manner, so that the sealing gasket has a structural layer made of expanded polytetrafluoroethylene and a structural layer made of elastic rubber. PTFE itself has chemical resistance, pressure resistance and high temperature resistance, and the cost is very low. The product has the characteristics of strong resistance, long life and low cost. At the same time, another structural layer provides elasticity to improve the structural quality. The additive effect can significantly reduce costs and improve product competitiveness.

O: Sealing ring

10: First structural layer

11: First joint surface

12:Outer surface

20:Second structural layer

21:Inner surface

22: Second bonding surface

Claims (4)

A sealing gasket includes: a sealing ring, including at least two structural layers of different materials, wherein one structural layer is made of expanded polytetrafluoroethylene (ePTFE); wherein the two structural layers are respectively a first structural layer and a second structural layer, wherein the material of the first structural layer is elastic rubber, and the material of the second structural layer is expanded polytetrafluoroethylene; wherein the two structural layers are made by one-piece double-material injection molding and polymerized into one body. The sealing gasket of claim 1, wherein the first structural layer is made of nitrile rubber (NBR) or butadiene rubber (BR). The sealing gasket of claim 1, wherein one of the two structural layers is located on the annular inner side of the sealing ring, and the other is located on the annular outer side of the sealing ring. The sealing gasket as described in claim 1, wherein one of the two structural layers is located on the top side of the sealing ring in the axial direction, and the other is located on the bottom side of the sealing ring in the axial direction.

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