Optimizing the Automated Cleaning Frequency for Stencil Printing Operation

Stencil cleaning is one of the important step and variable in stencil printing process. If the stencil is not cleaned regularly then solder paste deposition can be adversely affected. Solder paste printing defects such as insufficient solder paste on the pads due to stencil aperture clogging can be more prominent. Low stencil cleaning cycle frequency will lead to aperture clogging and high frequency of the same will hamper the production rate of the SMT process. To reduce the risk of one of these problems, stencil-cleaning frequency must be optimized for different categories of the boards.

RMA Database

The global objective of this project was to facilitate the RMA tracking process at building 2 and building 3 at Solectron by establishing a new system of RMA tracking. This project mainly concentrated on the RMA procedure for the assemblies in building 2 and building 3 at Solectron Corporation site from the customer, Sun Microsystems. The project dealt with various categories of the RMA printed circuit boards (PCB) with the procedure followed by Solectron Corporation for them. Considering the data tracking difficulties for Return Material Authorization (RMA) boards, a new system was developed to overcome those difficulties. The system was developed in MS Access2000. the advantages of the new system over the old system were easy data tracking, user-friendly interface, and less time consumption.

MRB Disposition

If there is a defect on a board at any stage of the assembly process, the board has to be reviewed and sent to Material Review Board (MRB) Area. The MRB process is described below. CATSWEB is the tool used for handling the MRBs. As CATSWEB system was very slow, it was difficult to get the data. Hence, a new database in MS Excel and MS Access was created to facilitate the handling of MRB. The database gives the exact amount of money attributable to MRB and the number of boards sorted on the disposition.

Corrective Action Requests Database

If a discrepancy occurs in the assembly process, a corrective action has to be taken to bring that anomaly to normalcy. The documentation for these corrective actions is called as Corrective Action Request (CAR). A database for all the corrective actions in building 2 and building 3 was created to facilitate the reporting of the CAR. The database gives the brief reports of all Open CARs, Closed CARs, Customer CARs, and Internal CARs. The report has links to comprehensive CAR files.

Evaluation and Validation of Cyber-Optics SE300

The Cyber-Optics SE300, an automated optical solder paste inspection system, was evaluated. Three evaluation criteria used were used, namely, repeatability evaluation, cycle time of the Cyber-Optics SE300, and yield analysis. Repeatability was evaluated using Measurement Systems Analysis (MSA) method. Yield analysis was carried out on three representative assemblies, which were, 'least aggressive' assembly, 'medium aggressive' assembly, and 'most aggressive' assembly, with sample size 150. The assemblies were categorized on the basis of number of fine pitch components on the board and size of the board.