Nanomanufacturing – the intentional synthesis, generation or control of nanomaterials or fabrication steps in the nanoscale, for commercial purpose – is encompassed by two primary methods. According to ISO/TS 80004-8:2015 – Nanotechnologies. Vocabulary. Nanomanufacturing processes, these include bottom up nanomanufacturing, “processes that use small fundamental units in the nanoscale to create larger functionally rich structures or assemblies”, and top-down nanomanufacturing, which refers to “processes that create structures at the nanoscale from macroscopic objects.”
These two processes are closely related, since bottom up manufacturing requires the use of top-down manufacturing to be able to utilize the microscopic structures needed to assure precision and sufficient design in any products fabricated through that method. To maintain quality and reliability in intricate nanomanufacturing practices, standardization is a necessity.
The ANSI Nanotechnology Standards Panel (ANSI-NSP) serves as the cross-sector coordinating body for the purposes of facilitating the development of standards in the area of nanotechnology.
One of the most common nanostructures is the carbon nanotube. This can come in a variety of forms, with single-walled nanotubes existing in the simplest sense. In single carbon layers of graphite, each carbon atom is bound to three neighbors in a honeycomb structure. Single-walled carbon nanotubes can actually contain differing geometric compositions, which alters their appearance and gives them either an armchair or zig zag configuration.
Guidance on how to list, illustrate, and define various characteristics of single-wall carbon nanotubes for industrial use is covered by IEC/PAS 62565-2-1 Ed. 1.0 en:2011 – Nanomanufacturing – Material specifications – Part 2-1: Single-wall carbon nanotubes – Blank detail specification, which is also from where the above figures derive.
Nano-carbon structures will find wide ranging applications. For electronic applications, knowing the surface conductance of carbon nanotubes is essential. This is accomplished through a microwave resonant cavity test method, which is non-contact, fast, sensitive, and accurate, being well-suited for standards, research and development, and for quality control in the manufacturing of two-dimensional nano-carbon materials. The microwave resonant test method is addressed in IEC/TS 62607-6-4 Ed. 1.0 en:2016 – Nanomanufacturing – Key control characteristics – Part 6-4: Graphene – Surface conductance measurement using resonant cavity. Note that this technical specification is intended for graphene, a material that we discussed in a past post as being the strongest material in the world.
The actual process of installing carbon nanotubes during the manufacturing of electronics would fall under bottom up manufacturing, in accordance with its definition from ISO/TS 80004, and this method is incorporated into semiconductor manufacturing on a large scale. Unfortunately, nanomaterials, due to the same size characteristics that make them desirable for manufacturing, represent a potential contaminant in semiconductor facilities, making it necessary to introduce them in a structured and methodical way.
IEC/IEEE 62659 Ed. 1.0 en:2015 – Nanomanufacturing – Large scale manufacturing for nanoelectronics was written with this interest in mind, having the intention of enabling the quick, low-risk adoption of nanomaterials into large-scale electronics manufacturing from a best set of common practices and specifications. These include “composition (material), density, purity, size/dimensions, properties such as electrical characteristics (conductive, non-conductive, and semiconductive), associated media (delivery medium), fabrication, surface functionalization, particle size distribution, surface area, shape, and degree of aggregation and agglomeration, etc.”
The standard also focuses on all aspects of the supply chain, making not only bottom up but also top-down manufacturing important to its guidelines. According to the document, the large scale manufacturing of nanoelectronics incorporates both of these methods, in addition to processes that utilize hybrid methods.
While electronics production is a major aspect of nanomanufacturing, it is by no means everything within the industry’s limits. For example, there is evidence that nanomanufacturing steel can actually make the end products ten times stronger.
Additional nanomanufacturing standards, specifying guidelines for different nanostructures and the procedures to create and use them, can be found by searching the ANSI Webstore.
1. International Electrotechnical Commission (IEC), IEC/PAS 62565-2-1: Nanomanufacturing –Material specifications – Part 2-1: Single-wall carbon nanotubes – Blank detail specification (Geneva: IEC, 2013), 9.