8 KW, 20 KW typical Common Mode Range -100 VDC to +100 VDC peak-to-peak Normal Mode Range 1.5 V to 200 V peak-to-peak Overrange Protection ±150 VDC, continuous Hysteresis 150 millivolts, typical Wave Shape Sine, square, pulse, etc. Duty Cycle 10% to
8 KW, 20 KW typical Common Mode Range -100 VDC to +100 VDC peak-to-peak Normal Mode Range 1.5 V to 200 V peak-to-peak Overrange Protection ±150 VDC, continuous Hysteresis 150 millivolts, typical Wave Shape Sine, square, pulse, etc. Duty Cycle 10% to
Used SMT Equipment | In-Circuit Testers
Aeroflex IFR RD-301A Weather Radar Test Set Tracking System The RD301A tracking system enables the test set to automatically acquire and track the transmitter frequency. This basic feature eliminates the need for constant re-tuning to compens
Used SMT Equipment | In-Circuit Testers
Aeroflex IFR RD-301A Weather Radar Test Set Tracking System The RD301A tracking system enables the test set to automatically acquire and track the transmitter frequency. This basic feature eliminates the need for constant re-tuning to compens
Used SMT Equipment | In-Circuit Testers
Rohde & Schwarz NRVS Power Meter Single Channel Power Meter NRVS is an ideal instrument for a great variety of power measurement applications in labs and systems. Thanks to its intelligent sensors with calibration data memory and thermocouple s
Used SMT Equipment | In-Circuit Testers
Rohde & Schwarz NRVS Power Meter Single Channel Power Meter NRVS is an ideal instrument for a great variety of power measurement applications in labs and systems. Thanks to its intelligent sensors with calibration data memory and thermocouple s
Used SMT Equipment | In-Circuit Testers
Rohde & Schwarz NRVS Power Meter Single Channel Power Meter NRVS is an ideal instrument for a great variety of power measurement applications in labs and systems. Thanks to its intelligent sensors with calibration data memory and thermocouple s
Technical Library | 2020-10-27 02:07:31.0
For companies that choose to take the Pb-free exemption under the European Union's RoHS Directive and continue to manufacture tin-lead (Sn-Pb) electronic products, there is a growing concern about the lack of Sn-Pb ball grid array (BGA) components. Many companies are compelled to use the Pb-free Sn-Ag-Cu (SAC) BGA components in a Sn-Pb process, for which the assembly process and solder joint reliability have not yet been fully characterized. A careful experimental investigation was undertaken to evaluate the reliability of solder joints of SAC BGA components formed using Sn-Pb solder paste. This evaluation specifically looked at the impact of package size, solder ball volume, printed circuit board (PCB) surface finish, time above liquidus and peak temperature on reliability. Four different BGA package sizes (ranging from 8 to 45 mm2) were selected with ball-to-ball pitch size ranging from 0.5mm to 1.27mm. Two different PCB finishes were used: electroless nickel immersion gold (ENIG) and organic solderability preservative (OSP) on copper. Four different profiles were developed with the maximum peak temperatures of 210oC and 215oC and time above liquidus ranging from 60 to 120 seconds using Sn-Pb paste. One profile was generated for a lead-free control. A total of 60 boards were assembled. Some of the boards were subjected to an as assembled analysis while others were subjected to an accelerated thermal cycling (ATC) test in the temperature range of -40oC to 125oC for a maximum of 3500 cycles in accordance with IPC 9701A standard. Weibull plots were created and failure analysis performed. Analysis of as-assembled solder joints revealed that for a time above liquidus of 120 seconds and below, the degree of mixing between the BGA SAC ball alloy and the Sn-Pb solder paste was less than 100 percent for packages with a ball pitch of 0.8mm or greater. Depending on package size, the peak reflow temperature was observed to have a significant impact on the solder joint microstructural homogeneity. The influence of reflow process parameters on solder joint reliability was clearly manifested in the Weibull plots. This paper provides a discussion of the impact of various profiles' characteristics on the extent of mixing between SAC and Sn-Pb solder alloys and the associated thermal cyclic fatigue performance.
Technical Library | 1999-05-07 08:57:51.0
As a first step towards a perceptual user interface, a computer vision color tracking algorithm is developed and applied towards tracking human faces. Computer vision algorithms that are intended to form part of a perceptual user interface must be fast and efficient. They must be able to track in real time yet not absorb a major share of computational resources: other tasks must be able to run while the visual interface is being used. The new algorithm developed here is based on a robust nonparametric technique for climbing density gradients to find the mode (peak) of probability distributions called the mean shift algorithm.
Technical Library | 2014-06-12 16:40:19.0
Occurrence of popcorn in IC packages while assembling them onto the PCB is a well known moisture sensitive reliability issues, especially for surface mount packages. Commonly reflow soldering simulation process is conducted to assess the impact of assembling IC package onto PCB. A strain gauge-based instrumentation is developed to investigate the popcorn effect in surface mount packages during reflow soldering process. The instrument is capable of providing real-time quantitative information of the occurrence popcorn phenomenon in IC packages. It is found that the popcorn occur temperatures between 218 to 241°C depending on moisture soak condition, but not at the peak temperature of the reflow process. The presence of popcorn and delamination are further confirmed by scanning acoustic tomography as a failure analysis.
WASET - World Academy of Science, Engineering and Technology
