It has been thought that fluoropolymers are widely used in the isotope field due to their extremely low trace metal content, corrosion resistance, wide operating temperature range and excellent chemical inertness. But when it comes to the earliest application industry of fluoropolymers, which industry do you think of? That’s right, it’s the “semiconductor industry.”
The semiconductor industry was one of the first to make widespread use of fluoropolymers.
With the continuous advancement of technology and the continuous pursuit of high quality of semiconductor products, semiconductor manufacturers have been pushing material suppliers to minimize, or even eliminate, any type of chemical or material contamination.
Fluoropolymers have become the materials of choice for critical semiconductor manufacturing applications, such as for liquid handling and shipping, chemical packaging, wafer handling and filtration. Because fluoropolymers are highly chemical resistant, they maintain excellent performance at extreme temperatures. And most importantly, the purity is very high.
Are ultrapure fluoropolymers the most logical solution if pollution is to be minimized at all costs?
In order to answer this question, as a professional manufacturer of fluoropolymer products, American Savillex Company interviewed Ashwin Rao, semiconductor manager of Daikin Industries Ltd. “Daikin” is the world’s leading supplier of fluoropolymers and fluorochemicals for the semiconductor industry.
Rao expressed his understanding of this issue: We start by selecting the best construction material for processing equipment, then optimizing processing conditions to minimize resin decomposition and using cleanrooms to control the manufacturing environment. We also pay special attention to the quality of packaging materials, which helps in limiting further trace metals and contaminants.”
(Semiconductor manufacturers place a high priority on eliminating contamination-induced excursions in the manufacturing process that can impact their process yield and profitability, by reducing extracted contaminants such as trace metals, organics and other particulates, high-purity fluoropolymers The resulting components allow semiconductor manufacturers to produce cutting-edge chips at low cost.)
PTFE (polytetrafluoroethylene) was the first fluoropolymer adopted by the semiconductor industry, followed by PFA (perfluoroalkane).
The main differences between those two materials are as follows:
1. PFA is melt processable: this means it can be heated to melt and then molded by injection molding or blow molding. PTFE, on the other hand, must be machined or compressed to form it.
2. PFA is cleaner. By “clean,” I mean that parts made with PFA have lower trace metal content than parts made with PTFE. the reason is: 1) The manufacturing process is different, the injection and blow molding process used by PFA is much cleaner than the machining and compression molding process used by PTFE; 2) The PFA raw material itself has a high-purity (ie ultra-low trace metal) grade, while PTFE generally cannot achieve the same purity.
It can be seen that while both fluoropolymers are well suited for production in the semiconductor industry, they differ significantly in terms of performance, application extremes and processing characteristics. The application of these two materials has its advantages and disadvantages.
PTFE parts are typically machined from compression-molded PTFE blanks and are used for containers, fittings, connectors, shipping containers and fluid transfer. PFA is more used in the manufacture of pipes, valves, tees, containers, etc. in the semiconductor industry. In addition, some components and products with complex structures cannot be realized by machining with PTFE, and can also be manufactured by molding with PFA. For fluid handling applications, PFA components can be fabricated by non-contact welding, which avoids contamination of the original molded part.
In terms of production cost, is it cheaper to use PTFE or PFA?
Using PTFE to process parts allows manufacturers to avoid the initial investment in molds produced with PFA (individual PFA molds require higher investment). However, due to the long time-consuming and expensive unit price of PTFE processing parts, especially when a large number of parts need to be processed gradually, this situation is more obvious. Therefore, when the demand is large, it is cheaper to switch to molded PFA than mechanically processed PTFE. saving. For example, a machined PTFE part costs $300 to produce, but the same part made from molded PFA costs only $50. Switching to PFA molding does come with a higher initial tooling cost, but if the demand is high, there is the potential for a quick payback.
Based on the above, although PTFE (polytetrafluoroethylene) is more widely used than PFA (perfluoroalkane) in semiconductor manufacturing, PFA is used more in key areas instead of PTFE. Typical applications are as follows:
1. The sample introduction system of the ICP-MS instrument for the measurement of low ppt level trace metals in the analysis of process chemicals and on-wafer VPD (Vapor Phase Decomposition) is made of PFA, not PTFE;
Cetac ASX Autosampler PFA injection tube
ITO, FTO conductive glass, silicon wafer PFA cleaning rack cassette wafer carrier
2. The bottles used to transport high purity acid (10 ppt grade) are also made of PFA, not PTFE.
PFA Reservoir Bottle for Microelectronic Silane Semiconductor Integrated Circuit
