Technical Library | 2019-08-08 10:23:51.0
High mix production is the mainstay of many electronics assembly plants. Lot sizes and board complexities vary and the boards are often mixed technology, comprising a blend of both surface mount and through-hole technology. Modularizing a production line enables a clear distinction between one type of assembly process and another. This article assumes a modern factory where a job can be routed to the selective soldering machine module, the hand assembly bench, or a combination of both. The decision rules of routing a circuit board through hand assembly versus automated selective soldering are discussed. Hand assembly soldering operations require no explanation.
Technical Library | 1999-05-06 12:08:08.0
Input voltage capacitors are typically the parts that fail first in a high power circuit. Today's requirements for increasingly smaller packages is driving high component densities in power systems, as in all systems. As the package size...
Technical Library | 2021-06-10 08:08:19.0
test equipment /FPC universal
Technical Library | 2018-08-08 21:55:00.0
180 °C and Td >400 °C. In addition to a high thermal stability, Material A also shows a dielectric loss factor lower than commercial phosphorus-based flame retardants.
Technical Library | 2006-10-26 08:08:00.0
There have been many studies of the causes of tombstoning; some published, some not. They tend to focus on a single process parameter as the root cause of tombstoning. However, there is no single process change that is a sure cure for tombstoning! Those that claim otherwise are either uninformed or trying to sell you something. Rather than limiting your view to a single solution, EFD recommends you heed all of the studies. Like pieces of a puzzle, each study does not reveal the whole picture, but looked at all together, the picture is clear.
Technical Library | 2013-08-08 15:23:11.0
In this project Machine Vision PCB Inspection System is applied at the first step of manufacturing, i.e., the making of bare PCB. We first compare a PCB standard image with a PCB image, using a simple subtraction algorithm that can highlight the main problem-regions. We have also seen the effect of noise in a PCB image that at what level this method is suitable to detect the faulty image. Our focus is to detect defects on printed circuit boards & to see the effect of noise. Typical defects that can be detected are over etchings (opens), under-etchings (shorts), holes etc...
Technical Library | 2022-08-08 15:06:06.0
Selective soldering has evolved to become a standard production process within the electronics assembly industry, and now accommodates a wide variety of through-hole component formats in numerous applications. Most through-hole components can be easily soldered with the selective soldering process without difficulty however some types of challenging components require additional attention to ensure that optimum quality is maintained. Several high thermal mass components can place demands on the selective soldering process, while the use of specialized solder fixtures, or solder pallets, often places additional thermal demand on the preheating process. Fine-pitch through-hole components and connectors place a different set of demands on the selective soldering process and typically require special attention to lead projection and traverse speed to minimize bridging between adjacent pins. Dual in-line memory module (DIMM) connectors, compact peripheral component interface (cPCI) connectors, coax connectors and other high thermal mass components as well as fine-pitch microconnectors, can present challenges when soldered into backplanes or multilayer printed circuit board assemblies. Adding to this challenge, compact peripheral component interface connectors can present additional solderability issues because of their beryllium copper base metal pins. Key Terms: Selective soldering, drop-jet fluxing, sustained preheating, flux migration, adjacent clearance, lead-to-hole aspect ratio, lead projection, thermal reliefs, gold embrittlement, solderability testing.
| 1 |
.png)
