An Overview of Materials Science in Printed Circuit Packaging

1984 ◽  
Vol 40 ◽  
Author(s):  
D. P. Seraphim ◽  
L. C. Lee ◽  
B. K. Appelt ◽  
L. L. Marsh
Keyword(s):  
Printed Circuit Board ◽  
Materials Science ◽  
Scientific Data ◽  
Circuit Board ◽  
Mechanical State ◽  
Printed Circuit ◽  
Control Techniques ◽  
And Diffusion ◽  
Scientific Base

AbstractA brief description of a set of processes and materials to make printed circuit panels will be given. Then we will discuss the multi-disciplines required for forming a scientific base and provide examples where the fundamentalist and often times specialist is providing the scientific data needed by the packaging engineer. Control techniques, characterization or otherwise basic information helpful in decision making is provided to the development and production groups. Specifically, the state of resin cure at critical steps in the process is used to demonstrate the inter-relation between cure, flow, and mechanical properties in affecting printed circuit board integrity. Finally, the complex role of moisture solubility and diffusion from the process environment in perturbing the chemical and mechanical state is discussed.

Influence of the area of a thermal pad on optical and thermal parameters of LED modules

Circuit World ◽  
2020 ◽  
Vol 46 (2) ◽  
pp. 65-70 ◽  
Author(s):  
Krzysztof Górecki ◽  
Przemysław Piotr Ptak
Keyword(s):  
Thermal Resistance ◽  
Power Density ◽  
Printed Circuit Board ◽  
Thermal Parameters ◽  
Circuit Board ◽  
Optical Parameters ◽  
Metal Core ◽  
Content Type ◽  
Printed Circuit

Purpose The purpose of this paper is to present and discuss the results of measurements illustrating influence of the area of a thermal pad and the kind of the used base on thermal and optical parameters of LED modules. Design/methodology/approach LED modules including six power LEDs are designed. In the layout of these modules, different areas of a thermal pad of each LED are used. These modules are made using the classical FR-4 base and metal core printed circuit board (MCPCB). Thermal and optical parameters of all the tested modules are measured using the method elaborated by the authors. Findings The obtained results of measurements prove that increasing the area of a thermal pad causes a decrease in thermal resistance of the tested LED modules and an increase in power density of the emitted light. The role of the area of a thermal pad is more important for the classical FR-4 base than for MCPCB. Research limitations/implications Investigations were performed for only two values of the area of thermal pads and selected values of LEDs forward current. Originality/value The presented results of investigations show how the used layout and type of the used base of these modules influence optical and thermal parameters of LED modules. Changing the base of a module can cause even a double decrease in thermal resistance and a double increase in power density of the emitted light.

Role of a Printed Circuit Board Copper Clad Current Collector in Supercapacitor Application

2019 ◽  
Vol 48 (9) ◽  
pp. 5835-5842 ◽  
Author(s):  
Shabeeba Pilathottathil ◽  
Mohamed Shahin Thayyil ◽  
M. P. Pillai ◽  
A. P. Jemshihas
Keyword(s):  
Printed Circuit Board ◽  
Current Collector ◽  
Circuit Board ◽  
Supercapacitor Application ◽  
Printed Circuit

CO2 Laser Induced Blind-Via for Direct Electroplating

2014 ◽  
Vol 875-877 ◽  
pp. 1352-1356 ◽  
Author(s):  
Yu Xin Huang ◽  
Wei He ◽  
Zhi Hua Tao ◽  
Huan Xv ◽  
Xv Luo
Keyword(s):  
Laser Beam ◽  
Beam Energy ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Printed Circuit ◽  
Copper Particles ◽  
Conductive Film ◽  
Film Layer ◽  
Electroplating Process

Blind-via plays a crucial role in interlayer interconnection of printed circuit board. To get the blind via metallized a direct electroplating process has been put forward by the way of a inducing CO2 laser beam irradiating the copper in the bottom of blind via. The method for direct electroplating of copper onto a non-copper platable layer has been investigated in blind via metalization. The regression analysis was used to discuss the laser beam energy in different parameters. The results of electroplated blind via showed that the copper in the bottom of blind via can be induced by CO2 laser, and the induced copper particles ejected to the hole wall plays a role of the conductive film layer that mainly composed of copper by electroless plating or carbon black conductive film during electroplating, plasma used in cleaning blind via can promote the sorption of induced copper particles onto the via wall.

Characteristics of Radiated Emission from a Printed Circuit Board with a Slit

2012 ◽  
Vol 132 (6) ◽  
pp. 404-410 ◽  
Author(s):  
Kenichi Nakayama ◽  
Kenichi Kagoshima ◽  
Shigeki Takeda
Keyword(s):  
Printed Circuit Board ◽  
Circuit Board ◽  
Printed Circuit ◽  
Radiated Emission

Confirming the Signal Integrity in Transmission of Digital Signals on Microstrip Straight Circuits via the Eye Diagrams

2014 ◽  
Vol 5 (1) ◽  
pp. 737-741
Author(s):  
Alejandro Dueñas Jiménez ◽  
Francisco Jiménez Hernández
Keyword(s):  
Integrated Circuits ◽  
Printed Circuit Board ◽  
Signal Integrity ◽  
High Volume ◽  
Information Storage ◽  
Circuit Board ◽  
Electromagnetic Simulation ◽  
Electronic Systems ◽  
Digital Signals ◽  
Printed Circuit

Because of the high volume of processing, transmission, and information storage, electronic systems presently requires faster clock speeds tosynchronizethe integrated circuits. Presently the “speeds” on the connections of a printed circuit board (PCB) are in the order of the GHz. At these frequencies the behavior of the interconnects are more like that of a transmission line, and hence distortion, delay, and phase shift- effects caused by phenomena like cross talk, ringing and over shot are present and may be undesirable for the performance of a circuit or system.Some of these phrases were extracted from the chapter eight of book “2-D Electromagnetic Simulation of Passive Microstrip Circuits” from the corresponding author of this paper.

Root Cause Analysis of a Connector Time-Delayed Fracture

2015 ◽  
Author(s):  
Prabjit Singh ◽  
Ying Yu ◽  
Robert E. Davis
Keyword(s):  
Printed Circuit Board ◽  
Ceramic Substrate ◽  
Circuit Board ◽  
Delayed Fracture ◽  
Ceramic Substrates ◽  
Printed Circuit ◽  
Root Cause ◽  
Chip Carrier ◽  
Electrical Connections ◽  
Grain Boundary Grooves

Abstract A land-grid array connector, electrically connecting an array of plated contact pads on a ceramic substrate chip carrier to plated contact pads on a printed circuit board (PCB), failed in a year after assembly due to time-delayed fracture of multiple C-shaped spring connectors. The land-grid-array connectors analyzed had arrays of connectors consisting of gold on nickel plated Be-Cu C-shaped springs in compression that made electrical connections between the pads on the ceramic substrates and the PCBs. Metallography, fractography and surface analyses revealed the root cause of the C-spring connector fracture to be plating solutions trapped in deep grain boundary grooves etched into the C-spring connectors during the pre-plating cleaning operation. The stress necessary for the stress corrosion cracking mechanism was provided by the C-spring connectors, in the land-grid array, being compressed between the ceramic substrate and the printed circuit board.

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