SMD placement on three-dimensional circuit boards

1999 ◽  
Vol 22 (2) ◽  
pp. 147-150 ◽  
Author(s):  
E. Zussman
Keyword(s):  
Three Dimensional ◽  
Circuit Boards

scholarly journals Three-dimensionally deformable, highly stretchable, permeable, durable and washable fabric circuit boards

2014 ◽  
Vol 470 (2171) ◽  
pp. 20140472 ◽  
Author(s):  
Qiao Li ◽  
Xiao Ming Tao
Keyword(s):  
Fatigue Life ◽  
Three Dimensional ◽  
Circuit Boards ◽  
Electrical Stability ◽  
Resistance Change ◽  
Structural Conversion ◽  
Punch Test ◽  
Dry Conditions ◽  
Highly Stretchable ◽  
Dimensional Ball

This paper reports fabric circuit boards (FCBs), a new type of circuit boards, that are three-dimensionally deformable, highly stretchable, durable and washable ideally for wearable electronic applications. Fabricated by using computerized knitting technologies at ambient dry conditions, the resultant knitted FCBs exhibit outstanding electrical stability with less than 1% relative resistance change up to 300% strain in unidirectional tensile test or 150% membrane strain in three-dimensional ball punch test, extraordinary fatigue life of more than 1 000 000 loading cycles at 20% maximum strain, and satisfactory washing capability up to 30 times. To the best of our knowledge, the performance of new FCBs has far exceeded those of previously reported metal-coated elastomeric films or other organic materials in terms of changes in electrical resistance, stretchability, fatigue life and washing capability as well as permeability. Theoretical analysis and numerical simulation illustrate that the structural conversion of knitted fabrics is attributed to the effective mitigation of strain in the conductive metal fibres, hence the outstanding mechanical and electrical properties. Those distinctive features make the FCBs particularly suitable for next-to-skin electronic devices. This paper has further demonstrated the application potential of the knitted FCBs in smart protective apparel for in situ measurement during ballistic impact.

Three Dimensional Packaging of Bare IC Into Printed Circuit Boards for SIP

2003 ◽  
Author(s):  
Erik Jung ◽  
Dirk Wojakowski ◽  
Alexander Neumann ◽  
Rolf Aschenbrenner ◽  
Herbert Reichl
Keyword(s):  
Thermal Management ◽  
Printed Circuit Boards ◽  
Electrical Contact ◽  
Autonomous Systems ◽  
Three Dimensional ◽  
Circuit Boards ◽  
Passive Components ◽  
Electronic Products ◽  
Printed Circuit ◽  
Manufacturing Methods

The demand to miniaturize products especially for mobile applications and autonomous systems is continuing to drive the evolution of electronic products and manufacturing methods. To further the miniaturization of future products the integration of functions on miniaturized subsystems, i.e. System-in-Package (SiP) is a promising approach. Here, use of recent manufacturing methods allows to merge the SiP concept with a volumetric integration of IC’s. Up to now, most of the systems make use of single- or double-sided populated system carriers. A new challenge is to incorporate not only passive components, but as well active circuitry (IC’s) and the necessary thermal management. Ultra thin chips (i.e. silicon dies thinned down to <50μm total thickness) lend themselves to reach these goals. Chips with that thickness can be embedded in the dielectric layers of modern laminate PCB’s. Micro via technology allows to contact the embedded chip to the outer faces of the system circuitry. The aspects of embedding and making the electrical contact as well as the thermal management are highlighted. Results on FEM simulations and technical achievements are presented.

scholarly journals Single-Sided Near-Field Wireless Power Transfer by A Three-Dimensional Coil Array

Micromachines ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 200 ◽  
Author(s):  
Amirhossein Hajiaghajani ◽  
Seungyoung Ahn
Keyword(s):  
Magnetic Field ◽  
Printed Circuit Boards ◽  
Signal To Noise Ratio ◽  
Near Field ◽  
3D Structure ◽  
Three Dimensional ◽  
Power Transfer ◽  
Circuit Boards ◽  
Wireless Power ◽  
Halbach Arrays

Wirelessly powered medical microrobots are often driven or localized by magnetic resonance imaging coils, whose signal-to-noise ratio is easily affected by the power transmitter coils that supply the microrobot. A controlled single-sided wireless power transmitter can enhance the imaging quality and suppress the radiation leakage. This paper presents a new form of electromagnet which automatically cancels the magnetic field to the back lobes by replacing the traditional circular coils with a three-dimensional (3D) coil scheme inspired by a generalized form of Halbach arrays. It is shown that, along with the miniaturization of the transmitter system, it allows for improved magnetic field intensity in the target side. Measurement of the produced magnetic patterns verifies that the power transfer to the back lobe is 15-fold smaller compared to the corresponding distance on the main lobe side, whilst maintaining a powering efficiency similar to that of conventional planar coils. To show the application of the proposed array, a wireless charging pad with an effective powering area of 144 cm2 is fabricated on 3D-assembled printed circuit boards. This 3D structure obviates the need for traditional magnetic shield materials that place limitations on the working frequency and suffer from non-linearity and hysteresis effects.

scholarly journals Use of a Two-Dimensional Simulation Model in the Thermal Analysis of a Multi-Board Electronic Module

1994 ◽  
Vol 116 (2) ◽  
pp. 126-133 ◽  
Author(s):  
C. Beckermann ◽  
T. F. Smith ◽  
B. Pospichal
Keyword(s):  
Heat Transfer ◽  
Simulation Model ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Circuit Boards ◽  
Depth Direction ◽  
Wide Range ◽  
Local Board ◽  
Dimensional Simulation ◽  
Effective Component

A study is reported of heat transfer and air flow in an electronic module consisting of an array of narrowly spaced vertical circuit boards with highly-protruding components contained in a naturally vented chassis. A two-dimensional simulation model is developed that accounts for heat transfer by conduction, convection, and radiation, and sensitivity studies are performed. Experiments are conducted using a specially constructed test module. Comparisons with the experiments reveal the need to calibrate the model by selecting an effective component height that represents the drag properties of the actual three-dimensional component geometry. The need to account in the model for heat losses in the depth direction is also discussed. The importance of accurate thermophysical properties and of multi-dimensional radiation is shown. Good agreement with measured velocities and local board temperatures is obtained over a wide range of power levels, and it is concluded that the calibrated model is capable of representing the thermal behavior of the present module.

Low-cost and compact 3D circularly polarized Microstrip antenna with high efficiency and wide beamwidth

2017 ◽  
Vol 9 (7) ◽  
pp. 1533-1540 ◽  
Author(s):  
Xi Chen ◽  
Zhen Wei ◽  
Dan Wu ◽  
Long Yang ◽  
Guang Fu
Keyword(s):  
Microstrip Antenna ◽  
Printed Circuit Boards ◽  
High Efficiency ◽  
Low Cost ◽  
3D Structure ◽  
Three Dimensional ◽  
Axial Ratio ◽  
Impedance Bandwidth ◽  
Circuit Boards ◽  
Circularly Polarized

A compact three-dimensional (3D) circularly polarized (CP) microstrip antenna is presented in this paper. The antenna adopts three low-cost printed circuit boards to form an integrated and closed 3D structure, and the radiation patch and the feed patches are etched on the surface of that. A crossed slot is cut on the radiation patch to miniaturize the antenna, and triangular feed patches are introduced to increase the bandwidths. In addition, because of the utilization of a low-loss series feed line, the antenna has a high efficiency of more than 95%. A prototype of the antenna is measured to validate the method. The dimensions of the antenna is 0.064λ × 0.36λ (λ is the wavelength in free space at 1.2 GHz). The results indicate that the impedance bandwidth for voltage standing wave ratio ≤ 2 reaches 23%, and the bandwidth for axial ratio (AR) ≤ 3 dB reaches 10.1%. In the overlap band, the gains are > 4.5dBic. Additionally, the 3 dB beamwidth is more than 114°, and the beamwidth for AR ≤ 3 dB is more than 131° at 1.2 GHz.

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