The design of the PCB is important as it affects the overall performance of the overall system. Overall, the project's primary purpose is to understand the process flow of PCB and to acquire knowledge about PCB manufacturing.
Background of Research
This chapter discusses the background of the research work, the problem statement, the objective of the research, the relevance of the research, the challenges faced in completing this project, the significance of the project and the contribution of the project. When testing, it is difficult to detect the circuit fault because there is a lot of wiring on the board.
The importance of the project is in terms of verifying the simulation circuit by making the PCB. The PCB fabrication process should be done in a sequential order to avoid any error affecting the accuracy of the output. If the PCB mask is slightly misaligned, the circuit traces will be in the wrong direction.
The circuit was simulated in Eagle Software so that the clear picture of the schematic can be analyzed. Once the fabrication of the PCB is completed successfully, the output of the project will be analyzed in terms of total gate drive loss, body diode conduction loss and switching power loss. A suitable component is selected based on the component's function and application on the PCB.
Based on the previous discussion, this completes objective two of the project, namely acquiring knowledge about PCB manufacturing. The average voltages obtained for both circuit designs are slightly higher compared to the simulation result. The significance of the project lies in verifying the simulation circuit with PCB manufacturing.
Objectives of Research
Relevancy of the Research
This is to ensure that knowledge about the printed circuit board (PCB) fabrication process flow is captured. While doing this project, knowledge and experience can be gained about the PCB manufacturing process flow, the importance of IC and electronic components on PCB boards, and the external factors that will affect the production validity.
The benefit derived from representing the circuit simulation in physical form on the PCB board is in the form of manual testing. The sequence of the literature review was based on the objective priority stated in Chapter 1. Process modeling develops a model to predict the relevance and compatibility of the pattern in PCB.
This is important to prevent both MOSFETS from turning on at the same time. The entire PCB layout will be printed onto the thin films and this process ultimately completed the first objective of the project. This problem was solved by creating separate ground paths for the critical part of the circuit, such as the circuit for SRBC with compensator and AGD.
This is one of the important steps to consider in creating PCB layout. Objective three of the project is to apply high frequency DC-DC converter to PCB manufacturing achieved by fabricating SRBC and AGD circuit on PCB. Comparison between simulation and experimentation result will be done by measuring the percentage difference of the outputs.
Significant of Project
Contribution of the Research
Partitioning of the PCB Layout
This is to avoid signal conductors coming into contact with the ground pins and therefore creating a Faraday shield. Faraday shield is a set of parallel wires attached to a common conductor at one end.
Grounding Schemes of PCB
The guard ring acts as a field-bounding sink and is placed around the edge of the power plane . To ground the connector on the printed circuit board, it is necessary to connect all connectors to the ground of the printed circuit board. This will affect the performance of the system as the signal cannot be controlled according to the desired state.
Installing decoupling capacitor on the PCB is important because it will smooth the oscillation of voltage from power supply to the IC. However, decoupling capacitor must be perfectly grounded to avoid any voltage drop and signal mismatch.
Synchronous Rectifier Buck Converter
This adjustment is a trade-off between increased cost and better converter efficiency. In addition, it is essential to ensure that SW1 and SW2 do not turn on at the same time . P ( ) = power loss in the switch when the switch is driven P ( ) = power loss in the door switch.
TD is defined as the dead time or simply known as the delay when the switch turns on and off.
Pulse Width Modulation
The output of the comparator which is the PWM signal will be generated and the signal will be in digital signal.
Adaptive Gate Drive
This is important so that the progress of the project is monitored and recorded, and also to ensure that it is completed on time. The most important aspect is regarding the breakdown of the PCB layouts, grounding schemes, interconnection traces and component placement. The required percentage is about 5% more or less from the actual specification of the component as given in the electronic data sheet of the component .
Output from the PWM will cause switches M1 and M2 to turn on alternately to allow current charging and discharging at the inductor, L1. Based on the previous research, grid spacing should be kept as short as possible because longer total trace length will cause increase in resistance, capacitance and inductance of the PCB. While drawing the schematic of the circuit, the grounding of the components is located separately from each other.
The results to be analyzed are the output voltage and the node voltage for both circuits. The experiment result is proven to be more accurate and precise compared to the simulation result because the lower forward voltage obtained will reduce the body diode conduction loss, Pbd and increase the circuit efficiency. The experimental analysis project of gate drive control system for DC/DC synchronous converter has provided insights about PCB fabrication and AGD converter performance study.
Software and Tool Required
Process Flow of PCB
The value of clearances must be as close as possible to the value mentioned in Figure 17. However, auto-routing will not be able to route and clear all redundant tracks. For single-sided PCB, only top layer will have the traces where the bottom layer is used to solder the components on the PCB.
To ensure that all settings and component placements are in the correct order, the circuit board layout is first printed on A4 paper. After all settings and results are correct, the PCB layout is printed on transfer film.
Knowledge About PCB Fabrication
Applying High Frequency DC-DC Converter on PCB Application.28
The electrolytic capacitors act as a filter for the circuit to smoothly convert the DC output. The results are analyzed and verified to obtain output ripple voltage, Vop-p, output ripple current, Iop-p, average output voltage, Vo (avg). These parameters are used for simulation in PSpice software and SRBC experimentation on the printed circuit board.
However, to have knowledge related to PCB manufacturing, the analysis of gate drive control system for synchronous DC/DC converters, which involved the application of SRBC and AGD circuits, is also important. These two circuits: SRBC and AGD compensator circuit and SRBC with PWM compensator which are manufactured on PCB.
The PCB design for SRBC with PWM circuit is fully completed with the percentage of routers between each component 100. The PCB layout for SRBC with compensator and AGD and also the PCB layout for SRBC with PWM are reviewed to make the board look efficient and reduce the error to a minimum level in PCB manufacturing phase. The comparison between SRBC with PWM and SRBC with compensator and AGD circuit will be analyzed and verified.
The results obtained are average output voltage and current of SRBC with compensator and AGD improved from average output voltage and current of SRBC with PWM. Output ripple voltage and current for SRBC with compensator and AGD should also be higher compared to SRBC with PWM. The waveform obtained from the simulation shows that forward voltage (Vf) present for SRBC-PWM is large value compared to SRBC-compensator-AGD circuit.
This difference leads to the conclusion that body diode conduction loss for SRBC-PWM is higher compared to SRBC-compensator-AGD circuit.
The percentage difference between the simulation result and the experiment result should be in the range below 5%. The level of difference between experimentation and simulation occurs due to the value of the component design parameters used between the simulation value and the experimental value. The result from simulation and experiment are compared and the best controller is concluded.
Finally, the contribution of the project is achieved that the best controller is proven to be the compensator-AGD. 14] “A Soft Switching Synchronous Buck Converter for Zero Voltage Switching (ZVS) under Light and Full Load Conditions” in IEEE Appl.
SRBC with Compensator -AGD
Comparison between Simulation and Experimentation
However, even though the percentage difference is higher, it does not affect the conclusion for this project that the efficiency and operation of the SRBC with compensator and AGD control circuit is better compared to the conventional SRBC. 1] Chien-Cheng Lee, Wu-Yung Chen, "Coin insertion technology for PCB thermal solution", in IEEE International Conference, vol4 pp 1-2, April 2007  Photolithography and Photoresist Retrieved from. 10] Printed Circuit Board (PCB) Design Issues, “Grounding Issues”, PCB Separation Method Research Journal, No.
16] Scott Deuty, “Optimizing Transistor Performance in a Synchronous Rectifier Buck Converter,” Semiconductor Applications Specialist, p. May 2008. Maksimovic, "Dynamic operation of sensorless dead-ends - timing optimization in digitally controlled DC-DC converters", in CoPEC Ann. 19] N.Z. Yahaya, K.M. Begam, M.Awan, K.M. Zaini, “A Novel Simple Predictive Control Scheme Approach in High Frequency Gate Driver Design” in IEEE International Conference: Electric Power and Industrial Electronic Systems EEIES, 2009.
Suhaimi, “Comparative study of multiple controller design for high frequency inverter”, Bachelor of Engineering (Hons) thesis, Universiti Teknologi Petronas, Malaysia 2011.