This special feature focuses on the latest trends in the dry vacuum pump industry. One comprehensive report along with 5 technical introductions will enhance the knowledge of users and manufactures of the dry vacuum pumps.

Positive displacement vacuum pumps are the most commonly used pumps in the wide range of industry and research applications. In particular, dry sealed vacuum pumps which had been developed as of the mid 1950s could provide important advantages such as oil-free vacuum system and less contamination problem caused by lubricant and were accepted favorably in the semiconductor industry. Until the present day, various types of dry sealed vacuum pump with different principle or design have been expanding steadily their range of application. In this article, the outline such as history and feature of the latest representative dry sealed vacuum pumps is described in order to understand application compatibility.

Diaphragm dry vacuum pumps are used in a wide range of industries, including low-vacuum applications for semiconductor manufacturing processes, analysis, physics and chemistry, medical care, and food industries. In this report, we introduce the features and structure of our diaphragm dry vacuum pumps, as well as the pumps in general.

Some dry pumps are equipped with an oil box or grease along with the bearings in a vacuum and are not necessarily oil-free. This article introduces a completely oil-free scroll pump. There are also scroll pumps that have bearings in the vacuum space and pumps that have bearings only in the atmospheric pressure space. Scroll pumps with bearings only in the atmospheric pressure space are completely oil-free dry pumps, with no back-diffusion of oil into the vacuum chamber. It also has excellent water vapor processing capacity and ease of maintenance by end users.

In the pursuit of miniaturization of devices, semiconductor manufacturing processes have developed nanometer-order microfabrication technology and three-dimensional processing technology, and as manufacturing technology evolves, it has become significantly more complex. Furthermore, while semiconductor manufacturing processes are evolving and production volumes are increasing, there is also the issue of increasing environmental burdens such as CO2 emissions during the manufacturing process. In 2021, we launched dry vacuum pump, Model EV-X which flexibly responds to the diversity and complexity of the evolving semiconductor manufacturing process and reduces environmental impact. Model EV-X has a wide range of process applicability due to its high flow performance and wide range temperature control function. And also contributes to reducing CO2 emissions through its smaller footprint and energy-saving performance.

Quietness has become one of the key performance requirements for many users of vacuum pumps. In responcse, we launched the new air-cooled dry pump ‘NeoDry-G’ series in 2022. ‘NeoDry-G’ series is significantly quieter than its predecessor, the ‘NeoDry-E’ series. This paper provides a brief introduction to the NeoDry-G series, detailing how the quietness was improved and how it was evaluated.

The market for dry vacuum pumps occupies a large part of vacuum pumps, however, it is largely composed of frontier industries such as semiconductors, and FPD. General industries such as vacuum sintering, extruders, chemical plants, and food processing have not been adopted dry vacuum pumps in full scale because of their initial and maintenance cost. Those general industries tend to utilize water ring vacuum pumps and oil-sealed rotary vacuum pumps, which are low in initial cost, have abundant results and are easy to introduce. In recent years, from the viewpoint of environmental impact have become important because of efforts toward sustainable society, dry pumps that do not require sealing water oil have begun to be fully adopted in general industries. Hereinafter, while describing status of dry pumps in general industries, we would explain screw type dry pumps and screw rotors, and introduce our products.

The operating pressure of a turbomolecular pump is several hundred Pa or less due to its pumping principle. Therefore, a dry vacuum pump is essential as a backing pump to achieve an oil-free environment. This report explains how dry vacuum pumps affect the pumping performance and reliability of turbomolecular pumps.

This report describes the usage, specification, troubles and the countermeasures of dry pumps in Japan Proton Accelerator Research Complex (J-PARC). In J-PARC, while dry scroll pumps (DSP) are widely used, many of them are being replaced with roots pumps due to frequent maintenance and troubles of DSP. Some of the facilities use roots pumps with special specifications, such as radiation resistant specifications, separate power supply, and with diaphragm type, etc. Although some problems have occurred with both DSPs and roots pumps, they have been addressed by revising maintenance methods and improving parts, contributing to stable operation for users.