Using DOE to improve COB bonbability
In recent years, the Chip-on-Board (COB) package technology has become popular in semiconductor industries. The COB technology, in which the dies are directly mounted onto a printed circuit board (PCB) with bonding wires connecting the die and leads. Besides solder bumps, wire bonding is still the most popular interconnect method. With the development of wire bonding technology in the COB package, we can realize advanced processes with good performance by new wire bonding equipment and more powerful software. However, there are still many challenges to be overcome in the bonding process. In this paper, we did experiments to optimize the bonding parameter using 1.0mil Au wire on COB and successfully found the optimal range of bonding parameters through DOE (Design Of Experiment). By the optimal solution, we further improved the bondability; the second bonding quality was also improved by using BSOB (Bond Stitch On Ball) bonding.
Dynamic response of a molded leaded package in wire bonding assembly process
In this paper, a 3-D finite element (FE) model was established to simulate the dynamic vibration in lead frame of molded leaded package (MLP during wire bonding process. The dynamic vibration response in the MLP will be examined. Four lead frame design options are investigated for their dynamic response during the wire bonding process. Two different wire bonding ultrasonic vibration directions are studied. Different wire bonding clamping methods are considered. Different polymer tape materials under lead frame are checked as well. Finally, the ball stitch on ball (BSOB) wire bonding and normal wire bonding process are compared. The FEA modeling results show that all of these factors have impacted on the neighbor leads' vibration response significantly. BSOB wire bonding method is a good method to reduce neighbor lead vibration for all four lead frame design options. This study helps to improve assembly yield in wire bonding process of a lead frame MLP.
Enhancing Effectiveness of Shell and Tube Heat Exchanger through Six Sigma DMAIC Phases
Abstract This research portrays the pilot implementation of Six Sigma DMAIC (Define-Measure-Analyze-Improve-Control) phases to improve the effectiveness of shell and tube heat exchanger in a small sized furnace manufacturing company. Shell and tube heat exchanger is one of the critical components of the furnace. The imperative objective is to improve the quality of the furnace through DMAIC phases. In define phase, the critical to quality (CTQ) parameter was identified as effectiveness in shell and tube heat exchanger through the voice of the customer (VOC) and Pareto Chart. In measure phase, the present effectiveness was measured as 0.61. In analysis phase, the reason for the reduction of effectiveness was identified as less heat transfer area through cause and effect diagram. In improve phase, the existing design was modified through various alternative solutions by conducting brainstorming sessions. In this phase, the solution was identified with the introduction of circular fins over the bare tubes to improve the effectiveness in the shell and tube heat exchanger. Consequently, the effectiveness has been enhanced from 0.61 to 0.664. In control phase, the control strategies were recommended to sustain the improvements in shell and tube heat exchanger. In the end, the annual monetary savings of Rs.0.34 million were achieved through the implementation of DMAIC phases in the furnace manufacturing company.