Surface mounted PCB cleaning process improvement and Its impact on manufacturing system performance

In the surface mount technology (SMT) assembly line, the printed circuit boards (PCB) are washed to remove the solder flux that was used while soldering to prevent oxidation. However the current cleaning method is highly ineffective in removing these solder flux residues. The solder flux residues cause many problems like electro-migration, improper mold underfill and increase the chances of failure. This project explores alternative methods for the cleaning process and also identifies the important factors involved in cleaning. A model of the SMT assembly line was created using ARENA software and the impact of the different alternatives on the manufacturing system's performance was analyzed using this model. The results indicate that the use of chemicals in the ultrasonic cleaning method gives the best cleanliness performance. The results of the manufacturing system analysis show that the PCB cleaning process is not the bottleneck process in the SMT line and hence none of the different alternatives significantly impacted the throughput rate, cycle time and inventory levels. Cost comparison results also indicate that using chemicals in the batch type ultrasonic machine was atleast 25% cheaper than using chemicals in either centrifugal machine or in in-line machine.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2011

Author dc:creator

• Rajendran, Nikith

Advisor dc:contributor.advisor

• Jung Hoon Chun.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/69491

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/69491