New Equipment | Assembly Services
Shindengen New and Original M1F60 in Stock IC SMD/SMT package M1F60 Rectifier Diodes SMD FC0402E50R0BST1 SMD Vishay 20+ RCP1206W50R0GEB SMD Vishay 21+ LPC1768FBD100K,551 LQFP-100 NXP 21+
New Equipment | Assembly Services
Xilinx New and Original XC7A35T-1CSG324C in Stock IC 324-LFBGA package XC7A35T-1CSG324C programmable device FC0402E50R0BST1 SMD Vishay 20+ RCP1206W50R0GEB SMD Vishay 21+ LPC1768FBD100K,551 LQFP-100
New Equipment | Assembly Services
Diodes New and Original SMAT70A-13-F in Stock IC DO-214AC package SMAT70A-13-F 400W Surface Mount Transient Voltage Suppressor CY62157EV30LL-45ZSXIT TSOP44 CYPRESS 21+ CRCW04020000Z0ED SMD VISHAY 22+ T
New Equipment | Assembly Services
Guosheng-BOCHEN New and Original 3006P-1-504LF in Stock IC Resistor/Potentiometer package 3006P-1-504LF Adjustable Resistor/Potentiometer CY62157EV30LL-45ZSXIT TSOP44 CYPRESS 21+ CRCW04020000Z0ED SMD VISHAY 22+
Technical Library | 2019-05-01 23:18:27.0
Moisture can accelerate various failure mechanisms in printed circuit board assemblies. Moisture can be initially present in the epoxy glass prepreg, absorbed during the wet processes in printed circuit board manufacturing, or diffuse into the printed circuit board during storage. Moisture can reside in the resin, resin/glass interfaces, and micro-cracks or voids due to defects. Higher reflow temperatures associated with lead-free processing increase the vapor pressure, which can lead to higher amounts of moisture uptake compared to eutectic tin-lead reflow processes. In addition to cohesive or adhesive failures within the printed circuit board that lead to cracking and delamination, moisture can also lead to the creation of low impedance paths due to metal migration, interfacial degradation resulting in conductive filament formation, and changes in dimensional stability. Studies have shown that moisture can also reduce the glass-transition temperature and increase the dielectric constant, leading to a reduction in circuit switching speeds and an increase in propagation delay times. This paper provides an overview of printed circuit board fabrication, followed by a brief discussion of moisture diffusion processes, governing models, and dependent variables. We then present guidelines for printed circuit board handling and storage during various stages of production and fabrication so as to mitigate moisture-induced failures.
Technical Library | 2017-11-15 22:49:14.0
While a significant level of voiding can be tolerated in solder joints where electrical conductivity is the main requirement, voiding at any level severely compromises thermal conductivity. For example, in LED lighting modules effective conduction of heat through the 1st level die attach to the substrate and then through the 2nd level attach to the heat sink is critical to performance so that voiding in the solder joints at both levels must be minimized. (...) In this paper, the authors will review the factors that influence the incidence of voids in small and large area solder joints that simulate, respectively, the 1st and 2nd level joints in LED modules and discuss mitigation strategies appropriate to each level. They will also report the results of a study on the effect on the incidence of voids of flux medium formulation and the optimization of the thermal profile to ensure that most of the volatiles are released early in the reflow process.
New Equipment | Test Equipment
feature • 100~130kV 5µm closed X-ray tube, high sensitive image intensifier with 200M mega pixels CCD camera • Multi-function intensifier with±60° tilt imitat
New Equipment | Test Equipment
feature • 100~130kV 5µm closed X-ray tube, high sensitive image intensifier with 200M mega pixels CCD camera • Multi-function intensifier with±60° tilt imitat
New Equipment | Test Equipment - Bond Testers
feature • 100~130kV 5µm closed X-ray tube, high sensitive image intensifier with 200M mega pixels CCD camera • Multi-function intensifier with±60° tilt imitat
New Equipment | Test Equipment - Bond Testers
• 100~130kV 5µm closed X-ray tube, high sensitive image intensifier with 200M mega pixels CCD camera • Multi-function workstation with±70° tilt and X-Y-Z-Q-M multi-axis movement and CNC auto-detect &bu
