German Tier 1 supplier Bosch is building the chip factory of the future in Dresden. Manufacturing of automotive microchips will be a primary focus when Bosch’s fully digital and highly connected semiconductor plant is up and running.
The company already operates a semiconductor fab in Reutlingen near Stuttgart. Bosch says the new wafer fab in Dresden is its response to the surging number of areas of application for semiconductors. The Tier 1 is investing around a billion euros (Rs 8,267 crore) in the high-tech manufacturing facility, which is said to be one of the most advanced wafer fabs in the world. Start of production is slated for July 2021.
The technology in focus at Bosch’s new Dresden facility is 300-millimeter fabrication, in which a single wafer can accommodate 31,000 individual chips. Compared with conventional 150- and 200-millimeter wafers, this technology offers the company greater economies of scale and boosts its competitiveness in semiconductor production. Moreover, fully automated production and real-time data exchange between the machines will make chip manufacturing in Dresden exceptionally efficient.
In the world of semiconductors, the term 'wafer' means a circular disc made of a material such as silicon. In what is known as a drawing process, a round monocrystal – the ingot – is created from extremely hot liquid silicon. The ingot may be 300 millimeters in diameter and more than one meter long. This cylinder is then sawed into discs – the raw wafers. These discs are thinner than a millimeter. In a manufacturing process lasting up to several month, these discs are turned into semiconductor chips.
Electronically connected, highly automated production
All the roughly 100 machines and lines in the 10,000-square-metre cleanroom are electronically connected – with each other and with the complex building infrastructure by means of a central database. To make this possible, 300 kilometres of data lines were laid. Such a setup allows as many as 1,000 data channels to be recorded for each machine in real time, and relayed to a server in the plant.
This centralised data architecture in the wafer fab is one of the biggest strengths of the new Bosch plant. Taken together, the production data generated is equivalent to 500 pages of text per second. In just one day, this would be equivalent to more than 42 million pages weighing 22 metric tons. One of the things this wealth of data allows is the ability to pinpoint at any time where each individual wafer is in the production process, where it is going next, and when it will arrive. The wafers are transported from machine to machine by a completely automatic system featuring individual pods known as FOUPs (front opening unified pods). Each FOUP can transport up to 25 wafers. There is no longer any manual transportation at all.
First AIoT factory
The Dresden wafer fab is Bosch’s first AIoT factory. AIoT stands for the combination of artificial intelligence (AI) and the internet of things (IoT). With this, Bosch is creating a sound basis for data-driven, continuous improvement in production, and setting new standards for Industry 4.0.
Artificial intelligence methods can be used to evaluate the data generated in the wafer fab. For example, an AI algorithm can detect even the tiniest anomalies in products. These anomalies are visible on the wafer surface in the form of specific error patterns known as signatures. Their causes are immediately analyzed and deviations from the process corrected without delay, even before they can affect the reliability of the product. This is the key to further improving the manufacturing processes and semiconductor quality, as well as to achieving a high level of process stability. In turn, it means that semiconductor products can go into full-scale production quickly.
Furthermore, AI algorithms can precisely predict whether and when a piece of manufacturing machinery or a robot needs maintenance or adjustment. In other words, such work is not done according to a rigid schedule, but precisely when it is needed – and well in advance of any problems cropping up. AI is also used in production scheduling, saving time and costs as it guides the wafers through several hundred processing steps at roughly 100 machines in the plant.
Plant with ‘digital twin’
There are two Dresden wafer fabs – one in the real world, and one in the digital world. Experts call this a ‘digital twin’. During construction, all parts of the factory and all relevant construction data relating to the plant as a whole were recorded digitally and visualised in a three-dimensional model. The twin comprises roughly half a million 3D objects, including buildings and infrastructure, supply and disposal systems, cable ducts and ventilation systems, and machinery and manufacturing lines. This allows Bosch to simulate both process optimization plans and renovation work without intervening in ongoing operations. Moreover, any new machinery is always delivered to the plant twice – once in the real world and once as a data model.