Technical Library | 2022-01-05 22:51:59.0
200 °C) and high pressure. In this paper, a small-molecule assisted approach based on dynamic reaction was proposed to dissolve thermosetting polymers containing ester groups and recycle electronic components from PCBs.
Technical Library | 2021-08-18 01:30:18.0
The interfacing of soft and hard electronics is a key challenge for flexible hybrid electronics. Currently, a multisubstrate approach is employed, where soft and hard devices are fabricated or assembled on separate substrates, and bonded or interfaced using connectors; this hinders the flexibility of the device and is prone to interconnect issues. Here, a single substrate interfacing approach is reported, where soft devices, i.e., sensors, are directly printed on Kapton polyimide substrates that are widely used for fabricating flexible printed circuit boards (FPCBs).
Technical Library | 2021-12-02 01:44:00.0
With the advent of Industry 4.0, production processes have been endowed with intelligent cyber-physical systems generating massive amounts of streaming sensor data. Internet of Things technologies have enabled capturing, managing, and processing production data at a large scale in order to utilize this data as an asset for the optimization of production processes. In this work, we focus on the automatic detection of physical defects in the production of surfacemount devices. We show how to build a classification model based on random forests that efficiently detects defect products with a high degree of precision. In fact, the results of our preliminary experimental analysis indicate that our approach is able to correctly determine defects in a simulated production environment of surface-mount devices with a MCC score of 0.96. We investigate the feasibility of utilizing this approach in realistic settings. We believe that our approach will help to advance the production of surface-mount devices.
Technical Library | 2021-02-04 01:56:56.0
In the present study, a model of closed-loop recycling of copper from PCBs is demonstrated, which involves the sequential application of bioleaching and electrowinning to selectively extract copper. This approach is proposed as part of the solution to resolve the challenging ... doi.org/10.1007/s12649-020-01128-9
Technical Library | 2015-10-29 18:19:33.0
With the electronic industry moving towards lead-free assembly, traditional SnPb-compatible laminates need to be replaced with lead-free compatible laminates that can withstand the higher reflow temperature required by lead-free solders. Lead-free compatible laminates with improved heat resistance have been developed to meet this challenge but they are typically more brittle than SnPb laminates causing some to be more susceptible to pad cratering. In this paper, two novel approaches for minimizing pad cratering will be discussed. Preliminary results which validate the two approaches will also be presented.
Technical Library | 2013-09-19 17:25:32.0
The next generation of smart phones will demand very thin multi-layer boards to reduce the product thickness again. This paper shows three different manufacturing approaches, which can be used for very thin any-layer build-ups. The technological approaches are compared on reliability level – the any-layer copper filled micro-via technology which is to be considered as state of the art technology for high end phones and the ALIVH-C/G technology that is well established in Japan. A test vehicle design featuring test coupons for comprehensive reliability test series has been defined as target application for investigation...
Technical Library | 2016-08-18 15:38:09.0
The Selective Reflow Rework Process is an approach to improving the high volume rework process, increasing process capabilities and process repeatability by using a standard reflow oven of 12 zones, pick and place machinery, semi-automated printing gear and Solder Paste Inspection (SPI) implementations. This approach was able to reduce the amount of rework equipment by more than half. Our human resource requirements (indirect and direct labor) were cut by more than 50% and our rolled throughput yield increased from 68.9% to 84.14%. The Selective Reflow Rework Process is less reliant upon operators and has become a repeatable, stable rework process.
Technical Library | 2017-06-29 16:39:30.0
Currently there is no industry standard test method for measuring dielectric properties of circuit board materials at frequencies greater than about 10 GHz. Various materials vendors and test labs take different approaches to determine these properties. It is common for these different approaches to yield varying values of key properties like permittivity and loss tangent. The D-24C Task Group of IPC has developed this round robin program to assess these various methods from the "bottom up" to determine if standardized methods can be agreed upon to provide the industry with more accurate and valid characteristics of dielectrics used in high-frequency and high-speed applications.
Technical Library | 2013-08-15 13:12:11.0
An automated visual PCB inspection is an approach used to counter difficulties occurred in human’s manual inspection that can eliminates subjective aspects and then provides fast, quantitative, and dimensional assessments. In this study, referential approach has been implemented on template and defective PCB images to detect numerous defects on bare PCBs before etching process, since etching usually contributes most destructive defects found on PCBs. The PCB inspection system is then improved by incorporating a geometrical image registration, minimum thresholding technique and median filtering in order to solve alignment and uneven illumination problem. Finally, defect classification operation is employed in order to identify the source for six types of defects namely, missing hole, pin hole, underetch, short-circuit, mousebite, and open-circuit.
Technical Library | 2018-02-28 22:28:30.0
Circuit functional density requirements continue to drive innovative approaches to high performance packaging. Some new approaches include; aggressive space reduction, embedded solutions, and those that offer some form of risk reduction and rework potential are now options that are being explored by customers. Requirements for assembly of these types of packages necessitate the deposition of solder paste and assembly of components into cavities of the substrates to gain z-axis density as well as area functional density. Advances in the fabrication of PWB’s with cavities using newly developed laser micro-fabrication processes along with increased circuit pitch density of 50 micron lines and spaces permit new applications for high performance electronic substrates. First published at SMTA Pan Pacific Symposium
