The author investigates the economic impact of processing technologies on the cost of MCM (multichip module) substrates using a technique called technical cost modeling. Using the technique and data collected from industry, a thin film MCM substrate technical cost model was developed. The model is used to evaluate the economics of different processing options for dielectric deposition and the use of photosensitive versus nonphotosensitive polyimides for via formation. The results have strong implications for both the users and manufacturers of MCMs.