What is the difference between batch and in-line processing when speaking about manufacturing?

Question

A quote from what I was reading:

Silicon solar cell manufacturers are switching from batch manufacturing to inline processes to lower the cost per watt produced. This creates strong demand for BTUI products.

Apart from the question above, how does in-line processing reduce cost?

It'll be much appreciated if laymen terms could be used as far as possible.

Answer 1

It's techno-babble by a journalist reciting some meaningless irrelevancies he was told. Batch and inline processes have different characteristics, but batch is not necessarily slower or more expensive. Most production processes are a combination of the two.

Semiconductors are currently made using many processes.  Many of them require putting a batch of product (aka production or fab lot) in an oven or other chamber, and heating it for hours. These are true batch processes, where the whole fab lot is in the oven for the whole time. Each operation is expensive, and the fab lot will often see one step several times, and is moved around the production floor getting the proper sequence of operations. The high cost of semiconductors is not from being processed in batches, which are much cheaper than processing individual integrated circuits, but from the large number of precision operations that are done on time/energy/capital  intensive equipment.

An inline production process has a production line where the product travels down a line, having one step after another done to it.

The real gains are not inline vs. batch, it is process change and simplification. The manufacturers are trying to change the design of the solars cells to something that is made quickly and easily with only a few processes on high speed equipment, rather than sitting for hours in ovens and chambers. A less efficient cell made faster and therefore much cheaper is generally more profitable.

Answer 2

Imagine you are building cars.  Batch processing is like a bunch of guys in a room building one car.  When they are done, they gather all the parts needed and then build another.  In-line processing means the fist guy lays down the frame, the next guy add a part, etc, until the car is done.  In-line processing is harder to organize but once you plan it all out, it is far more efficient than batch processing.  However there is more that can go wrong in in-line porcessing.  If a process is delicate and unpredictable, it might not lend itself to this high-efficiency method.