Technical Library | 2021-12-21 23:21:34.0
Points of discussion in "HDI Microvia Technology – Cost Aspects" are: - Reasons for the use of HDI technology - Printed circuit board (PCB) size - Number of layers - Stack-up and complexity - Other important cost influences -–Design rules -–Drilling costs -–Microvia filling
Technical Library | 2011-11-03 18:04:07.0
This paper presents the development of a novel vehicle-routing-based algorithm for optimizing component pick-up and placement on a collect-and-place type machine in printed circuit board manufacturing. We present a two-phase heuristic that produces soluti
Technical Library | 2008-11-20 00:46:10.0
The Sn/Ag/Cu family of alloys is the leading candidate for a lead-free alternative. The first part of this study was to determine if there is any significant difference between Sn/Ag/Cu alloys when used in automatic soldering equipment in terms of copper build-up in the system. The study compared two Sn/Ag/Cu alloys to determine if at processing temperatures one alloy would absorb less copper than the other alloy.
Technical Library | 2013-11-06 06:39:05.0
The set up of a turnkey conformal coating production line or facility, whether it is a batch or inline process, has many similar characteristics. Whether the coating application is based around a high volume selective coating robot, a batch dip coating system or a spray booth, the process requirements tend to be the same. This bulletin reviews the potential needs of the facility, including the process controls, environmental needs and health and safety issues and provides some starting points for a new facility.
Technical Library | 2015-02-12 16:57:56.0
Electronic systems are known to be affected by the environmental and mechanical conditions, such as humidity, temperature, thermal shocks and vibration. These adverse environmental operating conditions, with time, could degrade the mechanical efficiency of the system and might lead to catastrophic failures.The aim of this study is to investigate the mechanical integrity of lead-free ball grid array (BGA) solder joints subjected to isothermal ageing at 150°C for up to 1000 hours. Upon ageing at 150°C the Sn-3.5Ag solder alloy initially age-softened for up to 200 hours. This behaviour was linked to the coarsening of grains. When aged beyond 200 hours the shear strength was found to increase up to 400 hours. This age-hardening was correlated with precipitation of hard Ag3Sn particles in Sn matrix. Further ageing resulted in gradual decrease in shear strength. This can be explained as the combined effect of precipitation coarsening and growth of intermetallic layer. The fractured surfaces of the broken solder balls were also investigated under a Scanning Electron Microscope. The shear failures were generally due to ductile fractures in bulk solders irrespective of the ageing time.
Technical Library | 2021-05-26 00:53:26.0
This paper describes a copper electroplating enabling technology for filling microvias. Driven by the need for faster, smaller and higher performance communication and electronic devices, build-up technology incorporating microvias has emerged as a viable multilayer printed circuit manufacturing technology. Increased wiring density, reduced line widths, smaller through-holes and microvias are all attributes of these High Density Interconnect (HDI) packages. Filling the microvias with conductive material allows the use of stacked vias and via in pad designs thereby facilitating additional packaging density. Other potential design attributes include thermal management enhancement and benefits for high frequency circuitry. Electrodeposited copper can be utilized for filling microvias and provides potential advantages over alternative via plugging techniques. The features, development, scale up and results of direct current (DC) and periodic pulse reverse (PPR) acid copper via filling processes, including chemistry and equipment, are described.
Technical Library | 2001-04-24 10:41:53.0
Tau models describe the timing and functional information of component interfaces. Timing information specifies the delay in placing values on output signals and the timing constraints (set-up/hold, pulse-width) on input signals of a component. Functional information, through a finite state machine (FSM), specifies when output signal values change, when input signal values are latched, and how output values are determined as a function of input values.
Technical Library | 2017-04-13 10:57:53.0
Parylene has been used for decades as a barrier layer to protect critical devices and components. The parylene deposition process typically requires an adhesion promotion step to make sure the parylene adheres well to the base substrate. Typical adhesion methods don't work well on Kapton and Polyamide, until VSI Parylene came up with a solution.
Technical Library | 2022-04-27 01:34:43.0
SMD capacitors and resistors have small sizes and many models. Some manufacturers buy a lot of products and do not use them up in time. The problem of storage is always a headache. So how should chip capacitors and resistors be stored? There are also precautions when using chip capacitors. Please see the following information and hope it will help you.
Technical Library | 2022-10-13 13:02:11.0
Effective and reliable dispensing is based primarily on process technology that has been perfectly set up for the specific project. Anyone tasked with planning dispensing systems and responsible for the processes should know the principles and key factors involved so that the dispensing processes can be successfully implemented in cooperation with system and material partners. This White Paper explains the relevant aspects of process technology and provides valuable practical tips.
