High quality laser cutting of electronic printed circuit board substrates

Circuit World ◽  
2009 ◽  
Vol 35 (4) ◽  
pp. 46-55 ◽  
Author(s):  
X.C. Wang ◽  
H.Y. Zheng
Author(s):  
Mai Hong Hanh ◽  
Nguyễn Việt Tuyên ◽  
Pham Van Thanh ◽  
Hoang Chi Hieu

Abstract: High quality, high density, and well-aligned zinc oxide (ZnO) nanorods have been synthesized on cost-effective printed circuit board (PCB) substrates via a simple, seedless, one-step, low-temperature hydrothermal method based galvanic cell structure. It was found that the outer diameters of the ZnO nanorods range from 50 nm to 400 nm. The as-grown ZnO nanorods prefer to grow along the c axis. The morphologies of the ZnO nanorods were investigated by scanning electron microscope (SEM) and X-ray diffraction (XRD). The crystallinity properties were characterized by Raman spectroscopy and photoluminescence (PL) spectroscopy.


1984 ◽  
Vol 11 (3) ◽  
pp. 215-217
Author(s):  
I. Hajdu ◽  
P. Bánlaki ◽  
J. Pinkola ◽  
E. Tóth

Printed circuits make up to 20 to 40 per cent of the value of electronic circuits.Quality and reliability requirements have been boosted by the general use of complex integrated circuits. An economical and high quality production is preconditioned by the continuous checking of prime materials and technologies.After a brief review of checking methods, a short examination of quality testing of the end product (double - or multilayer printed circuit board) is given, involving checking methods of assembled and non assembled boards.


1999 ◽  
Author(s):  
David K. Biegelsen ◽  
Patrick Cheung ◽  
Lars E. Swartz ◽  
Warren B. Jackson ◽  
Andrew A. Berlin ◽  
...  

Abstract Electrostatic flap valves for rapidly modulating air flows through directed jets have been fabricated by simple lamination techniques as extensions to standard printed circuit board technology. The flaps have thicknesses of a few microns whereas the lateral dimensions are several millimeters. The laser cutting and lamination processes are described here and the characteristics of the valves are presented. Flow rise and fall times of order 1 ms are demonstrated, the variations of response times with drive voltage and pressure differential are shown, and lifetimes greater than 4 × 108 are reported.


2012 ◽  
Vol 132 (6) ◽  
pp. 404-410 ◽  
Author(s):  
Kenichi Nakayama ◽  
Kenichi Kagoshima ◽  
Shigeki Takeda

2014 ◽  
Vol 5 (1) ◽  
pp. 737-741
Author(s):  
Alejandro Dueñas Jiménez ◽  
Francisco Jiménez Hernández

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.


Author(s):  
Prabjit Singh ◽  
Ying Yu ◽  
Robert E. Davis

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.


Author(s):  
William Ng ◽  
Kevin Weaver ◽  
Zachary Gemmill ◽  
Herve Deslandes ◽  
Rudolf Schlangen

Abstract This paper demonstrates the use of a real time lock-in thermography (LIT) system to non-destructively characterize thermal events prior to the failing of an integrated circuit (IC) device. A case study using a packaged IC mounted on printed circuit board (PCB) is presented. The result validated the failing model by observing the thermal signature on the package. Subsequent analysis from the backside of the IC identified a hot spot in internal circuitry sensitive to varying value of external discrete component (inductor) on PCB.


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