Effect of Continuous and Discontinuous Fabrication and Reflow Processes on PWB Warpage

2005 ◽  
Author(s):  
Saket Karajgikar ◽  
Wonkee Ahn ◽  
Dereje Agonafer
Keyword(s):  
Manufacturing Process ◽  
Printed Circuit Board ◽  
Electronic Devices ◽  
Physical Structure ◽  
Circuit Board ◽  
Multilayer Structures ◽  
Curing Process ◽  
Electronic Components ◽  
Reflow Process ◽  
Printed Circuit

PWB also known as Printed Circuit Board (PCB) provides the physical structure for mounting and holding the electronic components and electrically connecting it. They are foundation of virtually all of the electronic devices. Typically they are multilayer structures consisting of organic/composites (e.g. FR4) and circuit layers, laminated together. Such multi-layered structures exhibit ‘board warpage’ during manufacturing process. It is a result of residual thermo-mechanical stresses along with any asymmetries (if present) during the curing process. This effect further increases when the board undergoes thermal cycling during component mounting and reflow process. Effect of different parameters such as board size, board thickness, and pressure (at the time of developing) on PWB warpage is studied.

Realistic warpage evaluation of printed board assembly during reflow process

2015 ◽  
Vol 27 (4) ◽  
pp. 137-145 ◽  
Author(s):  
Soonwan Chung ◽  
Jae B. Kwak
Keyword(s):  
Numerical Simulation ◽  
Boundary Conditions ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Contact Boundary ◽  
Electronic Components ◽  
Reflow Process ◽  
Common Component ◽  
Content Type ◽  
Printed Circuit

Purpose – This paper aims to develop an estimation tool for warpage behavior of slim printed circuit board (PCB) array while soldering with electronic components by using finite element method. One of the essential requirements for handheld devices, such as smart phone, digital camera, and Note-PC, is the slim design to satisfy the customers’ desires. Accordingly, the printed circuit board (PCB) should be also thinner for a slim appearance, which would result in decreasing the PCB’s bending stiffness. This means that PCB deforms severely during the reflow (soldering) process where the peak temperature goes up to 250°C. Therefore, it is important to estimate PCB deformation at a high temperature for thermo-mechanical quality/reliability after reflow process. Design/methodology/approach – A numerical simulation technique was devised and customized to accurately estimate the behavior of a thin printed board assembly (PBA) during reflow by considering all components, including PCB, microelectronic packages and solder interconnects. Findings – By applying appropriate constraints and boundary conditions, it was found that PBA’s warpage can be accurately predicted during the reflow process. The results were also validated by warpage measurement, which showed a fairly good agreement with one and another. Research limitations/implications – For research limitations, there are many assumptions regarding numerical modeling. That is, the viscoplastic material property of solder ball is ignored, the reflow profile is simplified and the accurate heat capacity is not considered. Furthermore, the residual stress within the PCB, generated at PCB manufacturing process, is not included in this paper. Practical implications – This paper shows how to calculate PBA warpage during the reflow process as accurately as possible. This methodology helps a PCB designer and surface-mount technology (SMT) process manager to predict a PBA warpage issue and modify PCB design before PCB real fabrication. Practically, this modeling and simulation process can be easily performed by using a graphical user interface (GUI) module, so that the engineer can handle an issue by inputting some numbers and clicking some buttons. Social implications – In a common sense manner, a numerical simulation method can decrease time and cost in manufacturing real samples. This PCB warpage method can also decrease product development duration and produce a new product earlier. Furthermore, PCB is a common component in all the electronic devices. So, this PCB warpage method can have various applications. Originality/value – Because of an economic advantage, the development of a numerical simulation tool for estimating the thin PBA warpage behaviour during reflow process was attempted. The developed tool contains the features of detailed modeling for electronic components and contact boundary conditions of the supporting rails in the reflow oven.

scholarly journals Research on Small Square PCB Rogowski Coil Measuring Transient Current in the Power Electronics Devices

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4176 ◽  
Author(s):  
Chaoqun Jiao ◽  
Juan Zhang ◽  
Zhibin Zhao ◽  
Zuoming Zhang ◽  
Yuanliang Fan
Keyword(s):  
Power Electronics ◽  
Printed Circuit Board ◽  
Electronic Devices ◽  
Rogowski Coil ◽  
Bipolar Transistors ◽  
Circuit Board ◽  
Power Electronic ◽  
Insulated Gate Bipolar Transistors ◽  
Printed Circuit ◽  
Internal Structures

With the development of China’s electric power, power electronics devices such as insulated-gate bipolar transistors (IGBTs) have been widely used in the field of high voltages and large currents. However, the currents in these power electronic devices are transient. For example, the uneven currents and internal chip currents overshoot, which may occur when turning on and off, and could have a great impact on the device. In order to study the reliability of these power electronics devices, this paper proposes a miniature printed circuit board (PCB) Rogowski coil that measures the current of these power electronics devices without changing their internal structures, which provides a reference for the subsequent reliability of their designs.

Effect of Manufacturing Process Parameters on Property Evolution of Printed Circuit Board Laminates

2012 ◽  
Author(s):  
Pradeep Lall ◽  
Vikalp Narayan ◽  
Jim Blanche ◽  
Mark Strickland
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Manufacturing Process ◽  
Printed Circuit Board ◽  
Statistical Significance ◽  
Circuit Board ◽  
Effect Of Temperature ◽  
Process Variables ◽  
Printed Circuit

The effect of temperature exposure encountered both during assembly and in fielded products, has a known influence on glass transition temperature of printed-circuit board (PCB) laminate materials. Printed circuit board laminates such as FR4 are composites of epoxy resin with woven fiberglass reinforcement. Interaction between manufacturing process variables that impact the changes in glass transition temperature (Tg) has been studied. The laminates studied have been broadly classified into high-Tg, and mid-Tg laminates. Different sets of reflow profiles were created by varying the process variables including, time above liquidus, peak temperature, ramp rate and cooling rate. The effect of multiple reflows encountered in normal assembly or board re-work has been studied by exposing the assemblies to multiple reflows between 2x–6x. Changes to the glass transition temperature have been classified by measurement of the glass transition temperature were measured via Thermo Mechanical Analysis (TMA). Statistical analysis of the variables has been used to determine the statistical significance of the measured changes for large populations.

scholarly journals Universal synthesis of conductive liquid network in polymers enabling elastic printed circuit board technology

2021 ◽  
Author(s):  
Jiheong Kang ◽  
Wonbeom Lee ◽  
Hyunjun Kim ◽  
Inho Kang ◽  
Hongjun Park ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Acoustic Field ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
System Level ◽  
Large Strains ◽  
Stretchable Electronics ◽  
Electronic Components ◽  
Conductive Liquid ◽  
Printed Circuit

Abstract Stretchable electronics are considered next-generation electronic devices in a broad range of emerging fields, including soft robotics1,2, biomedical devices3,4, human-machine interfaces5,6, and virtual or augmented reality devices7,8. A stretchable printed circuit board (S-PCB) is a basic conductive framework for the facile assembly of system-level stretchable electronics with various electronic components. Since an S-PCB is responsible for electrical communications between numerous electronic components, the conductive lines in S-PCB should strictly satisfy the following features: (i) metallic conductivity, (ii) constant electrical resistance during dynamic stretching, and (iii) tough interface bonding with various components9. Despite recent significant advances in intrinsically stretchable conductors10,11,12, they cannot simultaneously satisfy the above stringent requirements. Here, we present a new concept of conductive liquid network-based elastic conductors. These conductors are based on unprecedented liquid metal particles assembled network (LMPNet) and an elastomer. The unique assembled network structure and reconfigurable nature of the LMPNet conductor enabled high conductivity, high stretchability, tough adhesion, and imperceptible resistance changes under large strains, which enabled the first elastic-PCB (E-PCB) technology. We synthesized LMPNet through an acoustic field-driven cavitation event in the solid state. When an acoustic field is applied, liquid metal nanoparticles (LMPnano) are remarkably generated from original LMPs and assemble into a highly conductive particle network (LMPNet). Finally, we demonstrated a multi-layered E-PCB, in which various electronic components were integrated with tough adhesion to form a highly stretchable health monitoring system. Since our synthesis of LMPNet is universal, we could synthesize LMPNet in various polymers, including hydrogel, self-healing elastomer and photoresist and add new functions to LMPNet.

Process Improvement Using Design by Experiments

1994 ◽  
Author(s):  
Hsien-chen Li ◽  
Fuyau Lin
Keyword(s):  
Process Improvement ◽  
Manufacturing Process ◽  
Printed Circuit Board ◽  
Fractional Factorial Design ◽  
Time Budget ◽  
Fractional Factorial ◽  
Circuit Board ◽  
Printed Circuit ◽  
Printed Circuit Board Manufacturing

Abstract This paper present an approach to apply Design by Experiments for process improvement with the objectives to minimize cost and shorten investigation time. A case study of PCB (Printed Circuit Board) manufacturing process is chosen to illustrate this approach. A Fractional Factorial Design by Experiment was performed due to the constraints of the time, budget, and resources.

scholarly journals Thermal and Electrical Analysis of Solid Aluminium Capacitors

1987 ◽  
Vol 12 (3) ◽  
pp. 167-186 ◽  
Author(s):  
E. H.L.J. Dekker ◽  
C. J.M. Lasance
Keyword(s):  
Thermal Properties ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Electronic Components ◽  
Reverse Voltage ◽  
Printed Circuit ◽  
Electrolytic Capacitors ◽  
Extensive Analysis ◽  
Current Specification ◽  
Electrical Analysis

The thermal properties of electronic components partly determine the reliability of electronic equipment. For electrolytic capacitors, they also set the limits for the ripple current and voltage values.This article first discusses the voltage limits under various conditions of temperature, frequency and polarity. Then the connection of ripple current to these parameters and to the capacitor's resistance is treated.An extensive analysis is made of the influence of heat conduction in the capacitor and the printed-circuit board, for metal-cased as well as for epoxy-coated pearl types. The study pays particular attention to solid aluminium capacitors containing a manganese dioxide semiconductor. They have some extraordinary properties: a temperature range of at least – 80 to + 175℃, and an appreciable reverse voltage potential.These can be fully employed to improve the ripple-current specification.

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