Technical Library | 2020-12-07 15:26:06.0
Temperature cycling testing is a method of accelerated life testing done to PCCs that are exposed to normal operation temperature variations over its lifetime. During the testing, intermittent "open" failures can first occur at the hot and cold extremes of the test, exposing weaknesses in the design and assembly. A poor/weak solder joint fatigues, a via trace or barrel cracks, loose connections or a component fails all causing an intermittent open. When not at extreme temperatures, the PCC assembly relaxes, the "open" closes creating electrical connectivity. If you are monitoring the PCC under test in-situ you will know that an intermittent failure has occurred, and the test could be stopped for inspection. If in-situ monitoring was not implemented, you would not know if there were intermittent failures or not. The PCC gets powered up and works fine at room temperature.
Industry News | 2021-10-31 21:32:05.0
At present and in the future, the maintenance of the electrical control equipment, VFD (Variable Frequency Drive) will become the professional knowledge that all electricians need to master. As a reliable supplier of leading brands of VFDs for many years, OKmarts now shares ten simple and easy maintenance methods to the majority of VFD maintenance technicians. Hopefully these experience can help you in the maintenance of VFDs.
Industry News | 2021-12-06 20:13:05.0
At present and in the future, the maintenance of the electrical control equipment, VFD (Variable Frequency Drive) will become the professional knowledge that all electricians need to master. As a reliable supplier of leading brands of VFDs for many years, OKmarts now shares ten simple and easy maintenance methods to the majority of VFD maintenance technicians. Hopefully these experience can help you in the maintenance of VFDs.
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.
Industry News | 2014-11-11 19:09:40.0
Seika Machinery, Inc. announces a year-end special on the McDry DXU-1001.
Industry News | 2020-12-01 02:49:29.0
Seika Machinery, Inc. announces its year-end sale on select products. Significant savings are available for McDry cabinets, Sawa portable handy cleaners and Sayaka PCB routers while stock lasts.
Industry News | 2020-06-11 05:50:07.0
Seika Machinery, Inc. announces a special summer sale on select products. Significant savings are available for McDry cabinets, Sawa stencil cleaners, Sayaka PCB routers, Malcom viscometers, paste mixers and profiler systems while stock lasts.
Industry News | 2015-11-04 19:54:09.0
Seika Machinery is pleased to announce a special sale, effective immediately. Seika is offering significant savings on its McDry Ultra-Low Humidity Storage Cabinets while supplies last. All inventory McDry cabinets will be quoted with extra year-end discounts.
Industry News | 2022-10-28 05:51:41.0
Seika Machinery, Inc. is pleased to announce its year-end sale on select products. Significant savings are available for McDry cabinets, Sawa ultrasonic stencil cleaners, Sayaka PCB routers and Malcom process control equipment while stock lasts.
Industry News | 2023-08-29 07:28:07.0
Seika Machinery, Inc. is excited to announce an upcoming SMTA Technical Webinar titled "Effectiveness of Strain Gage Methodology for Durable Board Design." The webinar will be presented by Seika Machinery's principal, James Hara, Principal at Kyowa Electronic Instruments Co., Ltd.
COT specializes in high quality SMT nozzles and consumables for pick and place machines. We provide special engineering design service of custom nozzles for those unique and odd components.
2481 Hilton Drive
Gainesville, GA USA
Phone: (770) 538-0411
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