MID Fabricated by Ultrasonic Processing

2014 ◽  
Vol 1038 ◽  
pp. 83-88
Author(s):  
Werner Karl Schomburg ◽  
Ji Li ◽  
Sijie Liao ◽  
Christof Gerhardy ◽  
Johannes Sackmann
Keyword(s):  
Electronic Circuit ◽  
Electrical Contact ◽  
Ultrasonic Welding ◽  
Circuit Board ◽  
Circuit Boards ◽  
Electronic Components ◽  
Lateral Direction ◽  
Polymer Carrier ◽  
Cycle Times ◽  
Polymer Foils

Electronic circuit boards have been fabricated in cycle times of a few seconds by ultrasonic fabrication. A stack of thermoplastic polymer foils with a copper layer, 20 μm in thickness, on top is transformed into a polymer carrier with separated conductor paths. This process is accomplished in cycle times of a few seconds and the required equipment is just a commercially available ultrasonic welding machine and a metal tool micro patterned, e.g., by milling.Since soldering is often not possible on a thermoplastic carrier, electronic components are joined to the conductor paths by ultrasonic welding. This is achieved by employing an anisotropic conductive foil containing metal particles providing the electrical contact normal to the foil and showing no conductivity in lateral direction. The anisotropic conductive foil also serves as glue between circuit board and electronic components.

Reliability Monitoring in Drilling Electronic Circuit Boards

1991 ◽  
Vol 113 (3) ◽  
pp. 263-267 ◽  
Author(s):  
H. Hocheng ◽  
C. L. Jiaa
Keyword(s):  
Thermal Loading ◽  
Electronic Circuit ◽  
Processing Technique ◽  
Circuit Board ◽  
Circuit Boards ◽  
Signal Processing Technique ◽  
Reliability Monitoring ◽  
Long Term Performance ◽  
Term Performance

The purpose of the current study is to provide a monitoring scheme for evaluating the reliability of drilling of electronic circuit board (ECB) made of FR4 composite materials. The ECB is a laminated mechanical structure. Delamination often occurs at the hole exit during drilling. The resulted delamination deteriorates the long-term performance of the ECB when subject to mechanical and/or thermal loading. Acoustic emission can monitor the extent of this damage. A linear relationship exists between the size of delamination and the energy level of emitted signal when the proposed signal processing technique is used. The results contribute to higher quality ECB’s and can be applied in the manufacturing stage in an automated manner.

A Project of a System for Measuring Child's Foot Pressure on a Shoe Sole

2013 ◽  
Vol 208 ◽  
pp. 93-101
Author(s):  
Marcin Apostoł ◽  
Marcin Siwiecki
Keyword(s):  
Printed Circuit Board ◽  
Electronic Circuit ◽  
Circuit Board ◽  
Skeletal System ◽  
Electronic Components ◽  
Muscular System ◽  
Foot Pressure ◽  
Printed Circuit ◽  
Human Foot ◽  
Definition Of

The project of the system to measure a child's foot pressure on the sole of a shoe is the theme of this article. The skeletal system and muscular system of human foot were discussed. The movement of the foot was also depicted. The definition of gait and gait phases were explained. In the next part of this thesis, the project of system to measure a child's foot pressure on the sole of a shoe was presented. The thesis includes: the specification of the force-sensitive resistors (FSR), their arrangement and connection method. The electronic circuit diagram of the measurement system was designed. All electronic components such as: microcontroller, analog switches, operational amplifiers, multiplexers and RS485 transceivers were discussed in detail. The project of printed circuit board was also created.

Development of High Permeability Core Materials for Embeddable Inductors in Flexible Organic Substrates

2003 ◽  
Vol 769 ◽  
Author(s):  
C. K. Liu ◽  
P. L. Cheng ◽  
S. Y. Y. Leung ◽  
T. W. Law ◽  
D. C. C. Lam
Keyword(s):  
Low Temperature ◽  
Sol Gel ◽  
Circuit Board ◽  
Organic Substrates ◽  
Circuit Boards ◽  
High Permeability ◽  
Electrical Measurements ◽  
Different Temperatures ◽  
Spiral Inductors ◽  
Ceramic Tape

AbstractCapacitors, resistors and inductors are surface mounted components on circuit boards, which occupy up to 70% of the circuit board area. For selected applications, these passives are packaged inside green ceramic tape substrates and sintered at temperatures over 700°C in a co-fired process. These high temperature processes are incompatible with organic substrates, and low temperature processes are needed if passives are to be embedded into organic substrates. A new high permeability dual-phase Nickel Zinc Ferrite (DP NZF) core fabricated using a low temperature sol-gel route was developed for use in embedded inductors in organic substrates. Crystalline NZF powder was added to the sol-gel precursor of NZF. The solution was deposited onto the substrates as thin films and heat-treated at different temperatures. The changes in the microstructures were characterized using XRD and SEM. Results showed that addition of NZF powder induced low temperature transformation of the sol-gel NZF phase to high permeability phase at 250°C, which is approximately 350°C lower than transformation temperature for pure NZF sol gel films. Electrical measurements of DP NZF cored two-layered spiral inductors indicated that the inductance increased by three times compared to inductors without the DP NZF cores. From microstructural observations, the increase is correlated with the changes in microstructural connectivity of the powder phase.

Degradation Analysis of Thick Film Chip Resistors

2009 ◽  
Author(s):  
Bhanu Sood ◽  
Diganta Das ◽  
Michael H. Azarian ◽  
Michael Pecht
Keyword(s):  
Thick Film ◽  
Printed Circuit Board ◽  
Negative Resistance ◽  
Circuit Board ◽  
High Humidity ◽  
Circuit Boards ◽  
Chemical Modifications ◽  
Current Leakage ◽  
Printed Circuit ◽  
Degradation Analysis

Abstract Negative resistance drift in thick film chip resistors in high temperature and high humidity application conditions was investigated. This paper reports on the investigation of possible causes including formation of current leakage paths on the printed circuit board, delamination between the resistor protective coating and laser trim, and the possibility of silver migration or copper dendrite formation. Analysis was performed on a set of circuit boards exhibiting failures due to this phenomenon. Electrical tests after mechanical and chemical modifications showed that the drift was most likely caused by moisture ingress that created a conductive path across the laser trim.

Dielectric Breakdown in Printed Circuit Boards at Elevated Temperatures

1996 ◽  
Author(s):  
P. Singh ◽  
G.T. Galyon ◽  
J. Obrzut ◽  
W.A. Alpaugh
Keyword(s):  
Experimental Data ◽  
Thermal Degradation ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Elevated Temperatures ◽  
Dielectric Breakdown ◽  
Circuit Board ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Data Matching

Abstract A time delayed dielectric breakdown in printed circuit boards, operating at temperatures below the epoxy resin insulation thermo-electrical limits, is reported. The safe temperature-voltage operating regime was estimated and related to the glass-rubber transition (To) of printed circuit board dielectric. The TG was measured using DSC and compared with that determined from electrical conductivity of the laminate in the glassy and rubbery state. A failure model was developed and fitted to the experimental data matching a localized thermal degradation of the dielectric and time dependency. The model is based on localized heating of an insulation resistance defect that under certain voltage bias can exceed the TG, thus, initiating thermal degradation of the resin. The model agrees well with the experimental data and indicates that the failure rate and truncation time beyond which the probability of failure becomes insignificant, decreases with increasing glass-rubber transition temperature.

scholarly journals Eco-Friendly Lead-Free Solder Paste Printing via Laser-Induced Forward Transfer for the Assembly of Ultra-Fine Pitch Electronic Components

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3353
Author(s):  
Marina Makrygianni ◽  
Filimon Zacharatos ◽  
Kostas Andritsos ◽  
Ioannis Theodorakos ◽  
Dimitris Reppas ◽  
...  
Keyword(s):  
High Resolution ◽  
Form Factors ◽  
Circuit Board ◽  
Lead Free ◽  
Process Conditions ◽  
Solder Paste ◽  
Electronic Components ◽  
Successful Operation ◽  
Fine Pitch ◽  
Forward Transfer

Current challenges in printed circuit board (PCB) assembly require high-resolution deposition of ultra-fine pitch components (<0.3 mm and <60 μm respectively), high throughput and compatibility with flexible substrates, which are poorly met by the conventional deposition techniques (e.g., stencil printing). Laser-Induced Forward Transfer (LIFT) constitutes an excellent alternative for assembly of electronic components: it is fully compatible with lead-free soldering materials and offers high-resolution printing of solder paste bumps (<60 μm) and throughput (up to 10,000 pads/s). In this work, the laser-process conditions which allow control over the transfer of solder paste bumps and arrays, with form factors in line with the features of fine pitch PCBs, are investigated. The study of solder paste as a function of donor/receiver gap confirmed that controllable printing of bumps containing many microparticles is feasible for a gap < 100 μm from a donor layer thickness set at 100 and 150 μm. The transfer of solder bumps with resolution < 100 μm and solder micropatterns on different substrates, including PCB and silver pads, have been achieved. Finally, the successful operation of a LED interconnected to a pin connector bonded to a laser-printed solder micro-pattern was demonstrated.

PHM Features for Large Circuit Boards to Be Implemented Into Electric Drivetrain Applications

2021 ◽  
Author(s):  
Alexander Otto ◽  
Eberhard Kaulfersch ◽  
Prashant Kumar Singh ◽  
Claudio Romano ◽  
Marcus Hildebrandt ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Experimental Methods ◽  
Accelerated Ageing ◽  
Deformation Analysis ◽  
Electronic Control ◽  
Circuit Boards ◽  
Electronic Components ◽  
Printed Circuit ◽  
Early Warning Indicators ◽  
Warning Indicators

Abstract Canary structures being used as early warning indicators represent an important tool for condition and health monitoring of electronic components and systems. In this paper, printed circuit boards with canary structures based on SMD 2512 ceramic chip resistors with reduced solder pad sizes were studied. Focus of these investigations was set on thermo-mechanical and mechanical stresses caused by passive thermal cycling as well as by vibrational loads. For this purpose, experimental methods such as deformation analysis and accelerated ageing tests as well as finite element based methods were applied. In addition, an outlook on the implementation of these canary structures into dual inverter electronic control boards for electrical powertrain applications will be given.

Electrochemical Investigation Cu Corrosion Behaviour of Electronic Circuit Board in Base Electrolyte

2014 ◽  
Vol 556-562 ◽  
pp. 141-144
Author(s):  
Zhi Hua Tao ◽  
Bin Leng ◽  
Chong Wang ◽  
Ding Jun Xiao ◽  
Ze Tan ◽  
...  
Keyword(s):  
Potentiodynamic Polarization ◽  
Electronic Circuit ◽  
Corrosion Behaviour ◽  
Chloride Ions ◽  
Circuit Board ◽  
Corrosion Mechanism ◽  
Base Electrolyte ◽  
Eis Measurements ◽  
Inhibition Performance ◽  
Cu Corrosion

The eleetronic material, or even the whole equipments may be destroyed by very slight corrosion, so it is important to study the corrosion mechanism and corrosion protections. The Cyproconazole as a Cu corrosion inhibitor for Electronic Circuit Board in the base electrolyte (containing 70 ppm chloride ions, 0.54 mol/L H2SO4and 0.8 mol/L CuSO4) was investigated using polarization curves and AC impedance. The results showed that the inhibition performance of the Cyproconazole depended on the concentration of the inhibitor and the highest inhibition efficiency of the Cyproconazole reached 99.9% at 1×10-3mol/L in the base electrolyte. The results obtained from EIS measurements are in good agreement with that obtained from potentiodynamic polarization. Potentiodynamic polarization studies clearly revealed that Cyproconazole adsorption acted essentially as the mixed-type inhibitor.

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