Technical Library | 2014-07-31 16:36:59.0
Metal whiskers often grow across leads of electric equipment and electronic package causing current leakage or short circuits and raising significant reliability issues. The nature of metal whiskers remains a mystery after several decades of research. Here, the existence of metal whiskers is attributed to the energy gain due to electrostatic polarization of metal filaments in the electric field. The field is induced by surface imperfections: contaminations, oxide states, grain boundaries, etc. A proposed theory provides closed form expressions and quantitative estimates for the whisker nucleation and growth rates, explains the range of whisker parameters and effects of external biasing, and predicts statistical distribution of their lengths.
Technical Library | 2021-08-23 01:53:13.0
After the equipment was introduced, the production capacity was increased by 20%, and the number of operators was reduced by 50%. Employees' salary expenses have been reduced by RMB 120,000 per year, and the pass-through rate has increased by 10% .
Technical Library | 2015-04-29 03:48:39.0
SPI equipment is routinely used in Printed Circuit Board (PCB) manufacturing to monitor and control one of the most crucial steps affecting the finished quality of circuit board. Solder paste deposition is the key process in board assembly operations using SMT techniques. Our LSM™ system was the industry's first popular method of manually inspecting solder paste; our SE systems revolutionized SMT production by offering an automated method for performing in-process 3D inspection on the assembly line. SPI systems measure the height and volume of the solder pads before the components are applied and the solder melted, and when used properly, can reduce the incidence of solder-related defects to statistically insignificant amounts. Critical to the SPI measurement is the accuracy of the height measurement because that has a direct correlation with solder volume and defects.
Technical Library | 2019-02-13 13:45:11.0
Development of information and telecommunications network is outstanding in recent years, and it is required for the related equipment such as communication base stations, servers and routers, to process huge amount of data in no time. As an electrical signal becomes faster and faster, how to prevent signal delay by transmission loss is a big issue for Printed Circuit Boards (PCB) loaded on such equipments. There are two main factors as the cause of transmission loss; dielectric loss and conductor loss. To decrease the dielectric loss, materials having low dielectric constant and low loss tangent have been developed. On the other hand, reducing the surface roughness of the copper foil itself to be used or minimizing the surface roughness by modifying surface treatment process of the conductor patterns before lamination is considered to be effective in order to decrease the conductor loss. However, there is a possibility that reduction in the surface roughness of the conductor patterns will lead to the decrease in adhesion of conductor patterns to dielectric resin and result in the deterioration of reliability of PCB itself. In this paper, we will show the evaluation results of adhesion performance and electrical properties using certain type of dielectric material for high frequency PCB, several types of copper foil and several surface treatment processes of the conductor patterns. Moreover, we will indicate a technique from the aspect of surface treatment process in order to ensure reliability and, at the same time, to prevent signal delay at the signal frequency over 20 GHz.
Technical Library | 2021-06-07 19:10:16.0
The aim of this study was to compare leaching characteristics of metals from printed circuit boards (PCBs), taken from waste electrical and electronic equipment in the presence and in the absence of the iron-oxidizing bacteria, Acidithiobacillus ferrooxidans. A. ferrooxidans not only increases the leached concentration of Cu from the PCBs, but also inhibits the components of the 0K medium and leached Cu from forming precipitates such as libethenite (Cu2(PO4)(OH)), thereby assisting Cu recovery from the PCBs. In addition, the leached concentration of Pb from PCBs decreased in the presence of A. ferrooxidans, due to Pb forming amorphous precipitates. It is expected that Pb is not highly toxic to A. ferrooxidans. Consequently, A. ferrooxidans can be used as a cost-effective and environmentally friendly way to leach out valuable metals from PCBs as low-grade urban ore.
Technical Library | 2015-07-31 16:28:16.0
Technology is in constant change and circuit assembly is no different. It is becoming more and more advanced as needs change and demands for more capabilities increase. In order to meet these demands, equipment manufacturers are integrating the latest innovations and tools to serve the industry. The need to better protect printed circuit assemblies from harsh environments using automated selective conformal coating is becoming a must. 5 axis fluid dispensing allows conformal coating to be applied to printed circuit assemblies like never before.
Technical Library | 2016-10-27 16:24:23.0
Press-fit technology is a proven and widely used and accepted interconnection method for joining electronics assemblies. Printed Circuit Board Assembly Systems and typical functional subassemblies are connected through press-fit connectors. The Press-Fit Compliant Pin is a proven interconnect termination to reliably provide electrical and mechanical connections from a Printed Circuit Board to an Electrical Connector. Electrical Connectors are then interconnected together providing board to board electrical and mechanical inter-connection. Press-Fit Compliant Pins are housed within Connectors and used on Backplanes, Mid-planes and Daughter Card Printed Circuit Board Assemblies. High reliability OEM (Original Equipment Manufacturer) computer designs continue to use press-fit connections to overcome challenges associated with soldering, rework, thermal cycles, installation and repair. This paper investigates the technical roadmap for press fit technology, putting special attention to main characteristics such, placement and insertion, inspection, repair, pin design trends, challenges and solutions. Critical process control parameters within an assembly manufacturing are highlighted.
Technical Library | 2018-06-20 13:11:57.0
Manufacturers test to ensure that the product is built correctly. Shorts, opens, wrong or incorrectly inserted components, even catastrophically faulty components need to be flagged, found and repaired. When all such faults are removed, however, functional faults may still exist at normal operating speed, or even at lower speeds. Functional board test (FBT) is still required, a process that still relies on test engineers’ understanding of circuit functionality and manually developed test procedures. While functional automatic test equipment (ATE) has been reduced considerably in price, FBT test costs have not been arrested. In fact, FBT is a huge undertaking that can take several weeks or months of test engineering development, unacceptably stretching time to market. The alternative, of selling products that have not undergone comprehensive FBT is equally, if not more, intolerable.
Technical Library | 2021-05-20 13:45:49.0
Manufacturers test to ensure that the product is built correctly. Shorts, opens, wrong or incorrectly inserted components, even catastrophically faulty components need to be flagged, found and repaired. When all such faults are removed, however, functional faults may still exist at normal operating speed, or even at lower speeds. Functional board test (FBT) is still required, a process that still relies on test engineers' understanding of circuit functionality and manually developed test procedures. While functional automatic test equipment (ATE) has been reduced considerably in price, FBT test costs have not been arrested. In fact, FBT is a huge undertaking that can take several weeks or months of test engineering development, unacceptably stretching time to market. The alternative, of selling products that have not undergone comprehensive FBT is equally, if not more, intolerable.
Technical Library | 2015-04-08 11:10:47.0
An electronic schematic describes the electrical connectivity of a piece of equipment or an entire system. It is made up of symbols that represent individual components and contains electrical and mechanical information and their related connectivity, along with other important data. Information contained within the schematic is packaged into a printed circuit board (PCB) where the mechanical footprint is placed onto the board and connectivity information is graphically displayed. The more accurate the information contained in the schematic is and the clearer it is presented, the more it contributes to a robust printed circuit board.
Midwest Circuit Technology provides Carbide Router Bits and End Milling Cuters for use in PCB Depaneling equipment. We have over 35 years of supplying tools and machining experience in drilling, Routing, Test Fixture manufacture.
114 Barrington Town Square
Aurora, OH USA
Phone: 13309956900
