Technical Library | 2023-01-17 17:49:30.0
Repeatability of the Temperature Profile under Load Variation
Technical Library | 2023-01-17 17:27:13.0
Reflow profile has significant impact on solder joint performance because it influences wetting and microstructure of the solder joint. The degree of wetting, the microstructure (in particular the intermetallic layer), and the inherent strength of the solder all factor into the reliability of the solder joint. This paper presents experimental results on the effect of reflow profile on both 63%Sn 37%Pb (SnPb) and 96.5%Sn 3.0%Ag 0.5%Cu (SAC 305) solder joint shear force. Specifically, the effect of the reflow peak temperature and time above solder liquidus temperature are studied. Nine reflow profiles for SAC 305 and nine reflow profiles for SnPb have been developed with three levels of peak temperature (230 o C, 240 o C, and 250 o C for SAC 305; and 195 o C, 205 o C, and 215 o C for SnPb) and three levels of time above solder liquidus temperature (30 sec., 60 sec., and 90 sec.). The shear force data of four different sizes of chip resistors (1206, 0805, 0603, and 0402) are compared across the different profiles. The shear force of the resistors is measured at time 0 (right after assembly). The fracture surfaces have been studied using a scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS)
Technical Library | 2019-05-29 23:10:30.0
There are times when a PCB prototype needs to be built quickly to test out a design. In such cases where it is known early on that there will be multiple iterations or that a "one and done" assembly will be made that there will be some SMT assemblers who choose to hand print solder paste onto the board using a "frameless" stencil. In such cases where hand printing is used, the consistency of the printing technique has typically been in question. Furthermore, the effectiveness of both the nanocoatings as well as the higher end stainless steel materials, which have been heretofore studied in controlled printing environments, will be evaluated for their impact on the hand printing process.The purpose of the study was to determine the effectiveness of select nanocoating materials as well as certain high end stainless steel stencil materials as they relate to the manual SMT printing process. A variety of nanocoatings were applied to SMT metal stencils and solder paste volume measurements were taken to compare the effectiveness.
Technical Library | 2026-04-07 21:39:30.0
Field trials were conducted of wheat (Triticum aestivum) cv. Cadenza in which asparagine synthetase gene, TaASN2, had been knocked out, either on its own or together with a partial knockout of the related gene, TaASN1, using CRISPR/Cas9. Chemical mutagenesis (TILLING) TaASN2 nulls in the Claire background were also included. The main aim was to assess the free asparagine content of the grain and the conversion of free asparagine to acrylamide, a toxic contaminant, in bread, toast and biscuits. Over 2 years of trials combined, the TaASN2 and TaASN1/2 CRISPR knockouts resulted in a reduction of free asparagine in the grain of 59% and 93%, respectively, compared with Cadenza. The reduction in the TaASN2 total knockout TILLING line compared with Claire was 50%. Yield was not affected in the edited lines but was reduced in the TILLING lines. Acrylamide in bread made from a TaASN1/2 CRISPR line was below detection levels, while in a TaASN2 CRISPR line it was 14% of the Cadenza control. Even after 4min of toasting, acrylamide levels remained at 8% and 23%, respectively, of the control. The concentration in bread made from the TILLING TaASN2 knockout was 21% that for the Claire control, rising to 46% after 4min of toasting. Acrylamide in biscuits made from a TaASN1/2 CRISPR line was reduced by 93% compared with the control. The relationship between acrylamide and colour was altered in the edited and mutant lines compared with the controls, with less acrylamide forming for the same degree of colour.
Technical Library | 2023-09-16 07:06:30.0
Unlock enhanced efficiency and quality in LED strip production with our comprehensive production line solution. Streamline your processes and boost productivity today.
Technical Library | 2023-09-18 03:37:30.0
Revolutionize your PCB stenciling process with our cutting-edge SMT fully automatic stencil printer. Achieve unparalleled precision and efficiency. Explore our advanced stencil printing solutions today!
Technical Library | 2023-09-16 07:08:30.0
Elevate your LED production with our cutting-edge LED high-speed pick and place machine. Experience unmatched precision and efficiency to meet your manufacturing needs.
Technical Library | 2021-12-02 01:48:53.0
Some mechanical and assembly productions of existing companies of the Industry 3.0 and mechanical and assembly productions of perspective companies of the Industry 4.0 are described. The basic components of a smart factory and their interconnection to organize a production activity using humanless and paperless technologies are defined. A comparison analysis of parts and blanks movement to complete route sheet of the item manufacturing (radio and electronic item designing) in the companies of the Industry 3.0 and Industry 4.0 is given. The components of a digital item designing company to be created and implemented in the industry at first hand are defined.
University of Information Technologies, Mechanics and Optics [ITMO University]
Technical Library | 2024-05-28 20:18:30.0
Review of UV Laser Technology
Technical Library | 2024-10-01 14:36:30.0
Discusses the technology and process for laser cutting copper.
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