Masters Abstracts (1997)

RIELLY, LIAS
(June 1997), Baush & Lomb, Rochester, NY

Email: lmr94@fronitier.net

A Systematic Evaluation of Adhesive Deposition for Mixed Technology Assemblie

The assembly of mixed technology double sided boards (boards with through-hole and Surface Mount Components (or SMCS)) requires the use of adhesive on the bottom side of the PCB to hold the SMCs in place prior to and during the wave soldering process. Depositing the correct amount of adhesive in the correct position is critical for the assembly of mixed technology printed circuit boards. The objective of this research was to systematically study and evaluate the adhesive deposition process in a contract printed circuit board assembly environment. The adhesive deposition technique that was researched in this effort was syringe dispensing. The objective functions considered were the adhesive dot height, diameter, and volume. A systematic study of the initial capability to dispense adhesive was performed so that a 'base case' could be established for current and future research. During this time period, the machinery and process were studied and the properties of the adhesive used at the facility were researched. Due to this research, new process parameters were established for the storage, use and handling of adhesives used at the facility. A study of the machinery showed that there were six factors that may influence the amount of adhesive that is deposited. Three of these factors were software driven and thus were easy to determine and alter. The other three factors were hardware based and thus were more difficult to accurately determine and change. Taguchi methods were used for the initial process improvement Design of Experiments (DOE). Two machine parameters, stroke setting and syringe pressure, were found to have the largest influence on the adhesive volume. These two factors were studied extensively utilizing classical DOE techniques to determine appropriate value settings for the component types most frequently used at the facility. This research used systematic techniques to study an entire process and to help a facility determine methods for improvement of the process.