JCL Inc. is a major chip manufacturing firm that sells its products to computer

Question

JCL Inc. is a major chip manufacturing firm that sells its products to computer manufacturers like Dell, HP, and others. In simplified terms, chip making at JCL Inc. involves three basic operations: depositing, patterning, and etching.

• Depositing: Using chemical vapor deposition (CVD) technology, an insulating material is deposited on the wafer surface, forming a thin layer of solid material on the chip.

• Patterning: Photolithography projects a microscopic circuit pattern on the wafer surface, which has a light-sensitive chemical like the emulsion on photographic film. It is repeated many times as each layer of the chip is built.

• Etching: Etching removes selected material from the chip surface to create the device structures.

The table below lists the required processing times and setup times at each of the steps. There is unlimited space for buffer inventory between these steps. Assume that the unit of production is a wafer, from which individual chips are cut at a later stage.

Process Step               Depositing                  Patterning                   Etching

Setup time (min)                    45                         30                              24

Processing time (min) 0.1                        0.29 0.23

A. What is the process capacity in units per hour with a batch size of 125 wafers?

B. What is the utilization of depositing if the batch size is 125 wafers?

Explanation / Answer

A. Process Capacity = Batch/ (Setup time + Batch size*Time per unit)

With a batch size of 125, capacity at depositing is 125 /(45 + 125 * 0.1) = 2.17 per minute.

Similarly, capacity at patterning is 125 /(30 + 125 * 0.29) = 1.89 per minute

Capacity at etching is 125 /(24 + 125 * 0.23) = 2.37 per minute.

The process capacity that is the lesser of these three is 1.89

The capacity per hour is then 1.89*60 = 113.40 per hour.

B. Utilization of depositing = flow rate × processing time×100 = 1.89 units per minute × 0.1×100 = 18.9%

Related Questions

Navigate

• Browse (All)
• Browse J
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.