Technical Library | 2023-05-02 19:16:57.0
1.5 with a 150μm specification window. For 0201 components, the minimum requirement is CpK > 2.0 with a 100μm specification window. The spec window may need to be reduced down to 75μm if the controls for high volume manufacturing are insufficient. Also directly impacting the placement quality is the ability to apply sufficient solder consistently to the board. The goal is to maintain current printing practices, but the effect of powder size will be examined. This paper will evaluate the impact of placement accuracy and solder powder size on 0201 manufacturing quality.
Technical Library | 2012-04-09 14:08:18.0
As the electronics assembly industry evolves, printed circuit board (PCB) features and surface mount technology (SMT) components continue to get smaller and smaller. This miniaturization shrinks the process window at print, placement, and reflow, increasi
Technical Library | 2019-10-24 14:23:49.0
Presentation given by Fred Dimock during a seminar at the American Competitiveness Institute, ACI. •Recipe vs. Profile •Material Properties •Why profiles are shaped like they are. •Obtaining profiles •TC Accuracy •Profilers •Test vehicles •Process Window – Eutectic vs. Lead Free •Heat transfer •Oven Control
Technical Library | 1999-05-07 08:45:39.0
Fine pitch SMT devices, although certainly not new, present more of an assembly processing challenge than 50 mil pitch devices. In fact it seems that the finer the pitch the more difficult or narrower the process window becomes. Besides the pitch of the leads being less on fine pitch devices narrower pad width on the board is typical. With fine pitch designs the board fabrication process is also stressed in that the strip of mask between the pads is designed narrower, the alignment of the mask to copper becomes more critical
Technical Library | 2009-12-14 20:24:19.0
In the lead-free era, thermal profiling has a critical role in the SMT assembly process. We discuss the profiling, tools, practical issues, and inspection methods of golden boards, and related tools. As the process window narrows, profiling equipment and/or thermocouple (TC) errors must be taken into consideration. In addition, the accuracy and attachment method of the thermocouple will significantly impact critical assemblies.
Technical Library | 2022-10-31 08:43:27.0
Model/Specification: 12*16MM Common Name: Press Cover/GUIDE Suitable Fo: Siemens Feeder Parts Material: Ceramic Wight: 55g Quality: 100% Tested High Light: 12x16 Smt Spare Parts, 00328503, 00322753S04
Technical Library | 2009-12-23 16:55:08.0
Leading up to the development of lead-free soldering alloys, Horizontal Convection* was developed for the reflow process. Getting the correct temperature profile, with the narrow process window in lead-free applications, is now more important than ever. In each chamber or zone, air is circulated toward one side of the oven above the PCB and toward the opposite side of the oven below the PCB, forming a cyclone around the board. The forced air circulation results in a uniform temperature profile along the entire circuit board assembly. This technology is ideal for the precise profiles needed for lead free soldering.
Technical Library | 1999-05-07 10:04:13.0
Powerful desktop multiprocessor systems based on the Intel Architecture (iA) offer a formidable alternative to traditional scientific/engineering workstations for commercial application developers at an attractive costperformance ratio. However, the lack of adequate compiler and runtime library support for multithreading and parallel processing on Windows NT* makes it difficult or impossible to fully exploit the performance advantage of these multiprocessor systems. In this paper we describe the design, development, and initial performance results of the Illinois-Intel Multithreading Library (IML), which aims at providing an efficient and powerful (in terms of types of parallelism it supports) API for multithreaded application developers.
Technical Library | 2015-02-27 17:06:01.0
The drive towards fine pitch technology also affects the soldering processes. Selective soldering is a reliable soldering process for THT (through hole) connectors and offers a wide process window for designers. THT connectors can be soldered on the top and bottom side of boards, board in board, PCBs to metal shields or housing out of plastic or aluminum are today's state of the art. The materials that are used to make the solder connections require higher temperatures. Due to the introduction of lead-free alloys, the boards need more heat to get the barrels filled with solder. This not only affects the properties of the flux and components, but the operation temperatures of solder machines become higher (...)First the impact of temperature will be discussed for the separate process steps and for machine tooling. In the experimental part measurements are done to verify the accuracy that can be achieved using today's selective soldering machines. Dedicated tooling is designed to achieve special requirements with respect to component position accuracy.
Technical Library | 2024-06-23 22:03:59.0
The melting temperatures of most lead-free solder alloys are somewhat higher than that of eutectic Sn/Pb solder, and many of the alloys tend to wet typical contact pads less readily. This tends to narrow down the fluxing and mass reflow process windows for assembly onto typical organic substrates and may enhance requirements on placement accuracy. Flip chip assembly here poses some unique challenges. The small dimensions provide for particular sensitivities to wetting and solder joint collapse, and underfilling does not reduce the demands on the intermetallic bond strength. Rather, the need to underfill lead to additional concerns in terms of underfill process control and reliability. Relatively little can here be learned from work on regular SMT components, BGAs or CSPs.
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