Technical Library | 2018-08-01 11:25:59.0
With complexities of PCB design scaling and manufacturing processes adopting to environmentally friendly practices raise challenges in ensuring structural quality of PCBs. This makes it essential to have a good 'Design for Test' (DFT) to ensure a robust structural test. (...)During the course of the DFT review, can we realize a good test strategy for the PCBA. How can the test strategy of the PCBA be partitioned as to what portions of the design can be covered structurally and what is covered functionally, in a way that provides best diagnostics to discover faults
Technical Library | 2012-11-01 20:54:49.0
First published in the 2012 IPC APEX EXPO technical conference proceedings. The continuous progression toward portable, high frequency microelectronic systems has placed high demands on material performance, notably low dielectric constants (Dk), low loss tangent (Df), low moisture uptake, and good thermal stability. Epoxy resins are the workhorses of the electronic industry. Significant performance enhancements have been obtained through the use of PPE telechelic macromonomers with epoxy resins. However, there is a ceiling on the performance obtainable from epoxy-based resins. Therefore, non-epoxy based dielectric materials are used to fulfill the need for higher performance.
Technical Library | 2007-11-15 15:54:44.0
At the contractor level once a product is required to be soldered with lead-free solders all the processes must be assessed as to insure the same quality a customer has been accustomed to with a Sn63Pb37 process is achieved. The reflow, wave soldering and hand assembly processes must all be optimized carefully to insure good joint formation as per the appropriate class of electronics with new solder alloys and often new fluxes.
Technical Library | 2017-05-04 17:35:01.0
Most of today's printed circuit board base materials are anisotropic and it is not possible to use a simple method to measure thermal conductivity along the different axis, especially when a good accuracy is expected. Few base material suppliers' datasheet show X, Y and Z thermal conductivities. In most cases, a single value is given, moreover determined with a generic methodology, and not necessarily adapted to the reality of glass-reinforced composites with a strong anisotropy.After reminding of the fundamentals in thermal science, this paper gives an overview of the state-of the art in terms of thermal conductivity measurement on PCB base materials, and some typical values. It finally proposes an innovative method called transient fin method, and associated test sample, to perform reliable and consistent in plane thermal conductivity measurement on anisotropic PCB base materials.
Technical Library | 2018-04-18 23:55:01.0
Higher functionality, higher performance and higher reliability with smaller real estate are the mantras of any electronic device and the future guarantees more of the same. In order to achieve the requirements of these devices, designs must incorporate fine line and via pitch while maintain good circuitry adhesion at a smooth plating-resin interface to improve signal integrity. The Semi-Additive Process (SAP) is a production-proven method used on low dielectric loss tangent (Df) build-up materials that enables the manufacture of ultra-fine circuitry. (...) This paper will discuss a new SAP process for low loss build-up materials with low desmear roughness (Ra= 40-100 nm) and excellent adhesion (610-680 gf/cm) at various processing conditions. Along with the process flow, the current work will also present results and a discussion regarding characterization on the morphology and composition of resin and/or metal plating surfaces using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX), surface roughness analysis, plating-resin adhesion evaluation from 90o peel tests
Technical Library | 2022-06-27 16:50:26.0
Electronics industry is one of the fastest evolving, innovative, and most competitive industries. In order to meet the high consumption demands on electronics components, quality standards of the products must be well-maintained. Automatic optical inspection (AOI) is one of the non-destructive techniques used in quality inspection of various products. This technique is considered robust and can replace human inspectors who are subjected to dull and fatigue in performing inspection tasks. A fully automated optical inspection system consists of hardware and software setups. Hardware setup include image sensor and illumination settings and is responsible to acquire the digital image, while the software part implements an inspection algorithm to extract the features of the acquired images and classify them into defected and non-defected based on the user requirements. A sorting mechanism can be used to separate the defective products from the good ones. This article provides a comprehensive review of the various AOI systems used in electronics, micro-electronics, and opto-electronics industries. In this review the defects of the commonly inspected electronic components, such as semiconductor wafers, flat panel displays, printed circuit boards and light emitting diodes, are first explained. Hardware setups used in acquiring images are then discussed in terms of the camera and lighting source selection and configuration. The inspection algorithms used for detecting the defects in the electronic components are discussed in terms of the preprocessing, feature extraction and classification tools used for this purpose. Recent articles that used deep learning algorithms are also reviewed. The article concludes by highlighting the current trends and possible future research directions.
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