Technical Library | 2013-07-03 10:31:54.0
It has been demonstrated in numerous pieces of work that stencil printing, one of the most complex PCB assembly processes, is one of the largest contributors to defects (Revelino et el). This complexity extends to prototype builds where a small number of boards need to be assembled quickly and reliably. Stencil printing is becoming increasingly challenging as packages shrink in size, increase in lead count and require closer lead spacing (finer pitch). Prototype SMT assembly can be further divided between industrial and commercial work and the DIYer, hobbyist or researcher groups. This second group is highly price sensitive when it comes to the materials used for the board assembly as their funds are sourced from personal or research monies as opposed to company funds. This has led to development of a lower cost SMT printing stencil made from plastic film as opposed to the more traditional stainless steel stencil used by industrial and commercial users.This study compares the performance of these two traditional materials and their respective impact on solder paste printing including efficiency and print quality.
Technical Library | 2010-02-25 17:30:32.0
This paper will focus on two challenges: building differentiated products, which can enable systems companies to quickly penetrate a market, take a leadership position, and effectively counter or displace any competition; and build them faster. Clear differentiation also allows a superior value proposition, which will enable a stronger position on pricing with less need to circum to eroding ASPs. Differentiation can involve many factors, but this paper will focus on those related to the technology impact/usage that directly enables the design of products with shorter, more predictable design cycles compared to the competition.
Technical Library | 2021-11-22 20:39:44.0
Quality control is a key activity performed by manufacturing companies to verify product conformance to the requirements and specifications. Standardized quality control ensures that all the products are evaluated under the same criteria. The decreased cost of sensors and connectivity enabled an increasing digitalization of manufacturing and provided greater data availability. Such data availability has spurred the development of artificial intelligence models, which allow higher degrees of automation and reduced bias when inspecting the products. Furthermore, the increased speed of inspection reduces overall costs and time required for defect inspection. In this research, we compare five streaming machine learning algorithms applied to visual defect inspection with real world data provided by Philips Consumer Lifestyle BV. Furthermore, we compare them in a streaming active learning context, which reduces the data labeling effort in a real-world context. Our results show that active learning reduces the data labeling effort by almost 15% on average for the worst case, while keeping an acceptable classification performance. The use of machine learning models for automated visual inspection are expected to speed up the quality inspection up to 40%.
Technical Library | 2021-01-21 02:04:27.0
Traditional single level microvia structures are generally considered the most robust type of interconnection within a printed wire board (PWB) substrate. The rapid implementation of HDI technology now commonly requires between 2, 3 or 4 levels of microvias sequentially processed into the product. Recent OEM funded reliability testing has confirmed that by increasing the levels (stack height) these structures are proving less reliable, when compared to their single or double level counterparts. Recently false positive results have been recorded on products tested with traditional thermal shock testing methodology (cycling between -40°C and 125°C, or 145°C). A number of companies are incurring product failures resulting in increased costs associated with replacing the circuit boards, components and added labour.
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