Events Calendar | Wed Mar 18 00:00:00 EDT 2020 - Wed Mar 18 00:00:00 EDT 2020 | College Park, Maryland USA
CALCE Reliability Science Symposium - Spring 2020
Brass Panel Nuts UNEF BRASS PANEL NUTS BRASS LOCK NUTS ELECTRONIC HARDWARE ELECTRICAL PANEL NUTS Thread Size Across Flats Thickness Material Finishes 1/4-32 5/16 x 5/64 Inch
Training Courses | | | IPC-7711/7721 Specialist (CIS)
The Certified IPC-7711/7721 Specialist (CIS) training focuses on rework of electronic assemblies and repair and modification of printed boards and electronic assemblies.
Training Courses | | | IPC-7711/7721 Trainer (CIT)
The Certified IPC-7711/7721 Trainer (CIT) courses recognize individuals as qualified trainers in the area of rework and repair of printed boards and electronic assemblies and prepares them to deliver Certified IPC-7711/7721 (CIS) training.
Item Description Material : Tinplate, Nickel silver ,etc... Shield type :one piece ,two piece (frame and cover),shield clip Dimension: As your drawing Tolerance: +/-0.05mm ,If you have higher require please advise Process: Stamping ,plating if ne
Reel-to-reel plating; Wire bondable Gold, Silver, Copper, Nickel,...
Tin plated ,Nickel silver emi rf shielding Customized as your drawing ,ODM support
Technical Library | 2021-07-20 20:02:29.0
During the manufacturing of printed circuit boards (PCBs) for a Flight Project, it was found that a European manufacturer was building its boards to a European standard that had no requirement for copper wrap on the vias. The amount of copper wrap that was measured on coupons from the panel containing the boards of interest was less than the amount specified in IPC-6012 Rev B, Class 3. To help determine the reliability and usability of the boards, three sets of tests and a simulation were run. The test results, along with results of simulation and destructive physical analysis, are presented in this paper. The first experiment involved subjecting coupons from the panels supplied by the European manufacturer to thermal cycling. After 17 000 cycles, the test was stopped with no failures. A second set of accelerated tests involved comparing the thermal fatigue life of test samples made from FR4 and polyimide with varying amounts of copper wrap. Again, the testing did not reveal any failures. The third test involved using interconnect stress test coupons with through-hole vias and blind vias that were subjected to elevated temperatures to accelerate fatigue failures. While there were failures, as expected, the failures were at barrel cracks. In addition to the experiments, this paper also discusses the results of finite-element analysis using simulation software that was used to model plated-through holes under thermal stress using a steady-state analysis, also showing the main failure mode was barrel cracking. The tests show that although copper wrap was sought as a better alternative to butt joints between barrel plating and copper foil layers, manufacturability remains challenging and attempts to meet the requirements often result in features that reduce the reliability of the boards. Experimental and simulation work discussed in this paper indicate that the standard requirements for copper wrap are not contributing to the overall board reliability, although it should be added that a design with a butt joint is going to be a higher risk than a reduced copper wrap design. The study further shows that procurement requirements for wrap plating thickness from Class 3 to Class 2 would pose little risk to reliability (minimum 5 μm/0.197 mil for all via types).Experimental results corroborated by modeling indicate that the stress maxima are internal to the barrels rather than at the wrap location. In fact, the existence of Cu wrap was determined to have no appreciable effect on reliability.
Technical Library | 1999-05-07 11:28:39.0
There are many things that can go wrong when soldering to gold plate over nickel surfaces. First of all, we know that gold and solder are not good friends, as any time solder comes into contact with gold, something seems to go wrong. Either the solder bonds to the gold and eventually pulls off as the tin and gold cross-migrate, leaving voids; or the solder completely removes the gold and is expected to bond to the metal which was under the gold.
Technical Library | 2014-11-06 16:43:24.0
This paper summarizes the results of recent investigations to examine the effect of electroless nickel process variations with respect to Pb-free (Sn-3.0Ag-0.5Cu) solder connections. These investigations included both ENIG and NiPd as surface finishes intended for second level interconnects in BGA applications. Process variations that are suspected to weaken solder joint reliability, including treatment time and pH, were used to achieve differences in nickel layer composition. Immersion gold deposits were also varied, but were directly dependent upon the plated nickel characteristics. In contrast to gold, different electroless palladium thicknesses were independently achieved by treatment time adjustments.
.png)
