Author: EmanuelJ. Tucker Company: BenchmarkElectrorlics Date Published: 8/23/1998
Surface Mount International
Abstract: A comprehensive and practical program was initiated during 1997 to achieve significant yield improvement in the manufacturing of circuit card assemblies (CCAS). Over $230,000 of operating cost avoidance is projected on an annualized basis. Increased product yields were achieved throughout CCA final assembly and test at the contract manufacturer and systems integration at the customer site. This cost avoidance is due exclusively to a reduction in the level of defects and thereby relates directly to the “cost of quality”. This report covers only the labor and materials “cost of quality” components of total operating costs. These costs are referred to as “potential cost avoidance” due to two factors:  a till fiscal year has not been completed since the implementation of all the process improvements and  the annual volumes may vary. An annual volume of 120,000 CCAS is used as the baseline volume. The primary products are remote access servers with the typical CCA containing 75 actives and 400 passives with 6 fine pitch devices on a 6 layered double-sided board. The manufacturing process consists of side l/screen print, pick-n- place, reflow, side 2/adhesive, pick-n-place, cure, hand assembly, wave solder, post wave assembly, in-circuit test (ICT), quick verify test (QV), electrical stress screening (ESS) and final test. Systems integration occurred at the customer site. The environment consists of medium volume/high mix contract manufacturing with five production lines. The improvements noted herein were achieved on the one production line that ships -2,500 communication products per week across 45 different CCAS contained within 19 product families.