The Control System Design Of Time-pressure Dispensing For Flip-chip Packaging

Fluid dispensing, as one of the important processes in flip chip packaging, has a greatimpact on the microelectronics industry. Many industries can be improved if the qualityand efficiency of time pressure dispensing can be improved, because it is the most widelyused dispensing technology nowadays. However, since time pressure dispensing processcould be affected by many factors such as the inflation time, the pressure, thecharacteristic of the fluid etc., that it is difficult to control this process. In order to controlthe size of the fluid drops, this paper demonstrated the control system design as well as theresearch on the modeling of dispensing process and control methods.Control system is designed for flip chip packaging equipment. By analyzing theconditions and requirements of the dispensing process, and by comparing the architectureof a number of modern industrial control systems,"IPC plus motion control card" isselected. The control system based on the PMAC motion card is designed, this paper alsodrew the action flowchart of the dispensing by analyze the dispensing process.The model of the time pressure dispensing process is set. By analyzing the factors thataffect the dispensing process and how these factors affect the process, the most importantfactors are determined. This paper concludes the flow model of the process by analyzingthe characteristics of fluid, and also presents the development of a model describing howthe volume average pressure in the syringe varies by defining the unsteady time-pressuredispensing inflation process as a thermal insulation process. Additionally, a finite elementsimulation is performed to test the model by using Fluent. The results show that theanalytical solution and the simulation results match well.The feedback control method for the dispensing process of the flip chip packagingequipment is designed. The two-dimensional visual online measurement is applied tomeasure the fluid drops. The edge detection and circle fitting technologies were occupiedfor the image processing and he information got by the vision system is used as thefeedback to compensate the size of the fluid drops. Experiments and simulations areperformed to validate the method and show that the method could effectively control theprocess and meet the requirements.This paper researches on the dispensing process and its control methods, and ideas inthis paper could be useful for further research, especially when developing the controlsystem of a flip chip packaging equipment.