Smart Factory: Particle Monitoring Part I

“Every particle counts! Size really matters!”

The manufacturing environments of pharmaceutical and semiconductor have strict requirements for minimizing dust, airborne organisms or vaporized particles.  These isolated areas or rooms are referred to as a “Clean Room”.  A Class 1,000 clean room is equivalent to an ISO 6, which contains 102,000 particles that are bigger than 0.3 µm in size for each cubic meter.  However, a Class 100 clean room is often requirement for the manufacturing environment which can only contain 10,200 particles that are 0.3 µm in size or smaller per cubic meter!

There are several clean room standards, typically ISO 14644-1 and FED STD 209E.  The following Figure-1 table summarizes these standards and their equivalence.  MtM+’s solution supports Class 100 and higher.

Figure-1 Cleanroom classification and standardization

The existing industry solution to ensure a clean environment is to manually measure the number of particles in air using a portable meter (ie. MetONE HHPC3).  Typically, this can only be done once a day and only in few specific areas.  One can see that, such manufacturing environment can not react to contamination quick enough which result in defects and fallouts. 

“A Better Turnkey Solution for Particle Monitoring!”

MtM+’s Smart Factory solution provides an innovative approach with cutting edge technology to remotely measure particles in various critical location spots by strategically installing particle sensing nodes (PSN) throughout the clean environment in a mesh networking style.  A Bluetooth Low Power (BLE) Mesh network is used to transmit data from the sensors back to a local backend server as shown in the Figure-2 below.  Real-time data are collected with the options to either be analyzed locally or through a cloud network.

Figure-2 MtM+’s Mesh PSN Solution

Each PSN is equipped with state-of-the-art sensors that count particles with the light scattering method.  It typically can detect particles sizes from 0.3 µm to 10 µm with a counting efficiency of 50% (+/-20%) at 0.3um.  The size of the PSN box is 75mm by 72mm by 42mm (see below figure), which is small enough to be effectively placed in most environments. 

“Every labor counts! Time really matters!”

Utilizing the Mesh PSN technology can not only help reduce the labor cost and time, but also provide a much better and efficient way to help you analyze and collect the data precisely and further improve the quality of the manufacturing.  Figure-3 is a comparison between manual measurement and measurement using mesh PSNs.

Figure-3 Comparison between MtM+ solution and manual measurement

“Actual Deployment at the Customer’s Cleanroom.”

On-site deployment is never an easy task. However, MtM+’s dedicated special solution team will find out the best locations for particle monitoring and quickly deploy our wireless mesh nodes without rewiring or opening a big hole and re-bury tubes or wires in the wall. The figure-4 below is a real case of our on-site PSN deployment at one of our semiconductor customer’s factory floor. 8 cleanroom monitoring segments have been pre-defined by our customer and we decided to place our 15 pcs of PSNs at those selected critical area after our inspection and discussion with customer. Only one server is needed to collect those scattered sensor nodes due to the advantage of MtM+’s Mesh PSN technology.

Figure-4 Customer Factory Floor Layout & Deployment

As one can see in the figures-5 below, our solution will help visualize the data collected to help user better monitor the fluctuation of particle changes (one frame per 10mins, 144 frames per day) more frequently at the whole area within the whole day, comparing to manually measuring approach at much fewer spots and mostly 2~3 times per day in the past.

Our customer actually got notified by more alarms and thus captured an issue on the manufacturing floor, and later resolve the problem that could potentially harm it’s process by replacing the floor pieces with ventilated ones.

Figure-5 Left: 24-hours Space distribution of particle numbers.
Right: 24-hours Accumulative alarm events counts by clean room segments

The figure-6 below are the standard features of our server-based dashboard GUI that can further help users perform device management and data analysis etc.

Figure-6 MtM+ Smart Factory Dashboard Features

“More Applications on The Way”

Beside measuring air quality in a clean room, due to the small size of these PSN nodes, it can reside inside the manufacturing equipment itself (see figure-7 below).  This takes particle measurement to another level and ensuring maxim µm yield in any manufacturing environment.

Figure-7 Particle Sensing Nodes Reside Inside Main Equipment

“We need your Feedback!”

MtM+’s smart factory solution on particle monitoring has been deployed in a semiconductor manufacturing company with great results. Big data generated with these PSN boxes are vital for analysis in improving factory flow, floorplan and process. The keys to success are strategic placement of each sensors along with MtM+’s calibration algorithm, and we will cover more about our calibration process and benchmark details in the next article.

Real-time data are also essential to prevent possible disasters before it’s too late.  For more information on this technology and MtM+’s offerings, please email