Technical Library | 2023-01-10 20:03:37.0
Since the IPC-4552 rev A for ENIG was introduced there have been many requests for clarification of acceptable and unacceptable levels of nickel corrosion. This paper attempts to further clarify the effects of nickel corrosion on solder wetting balance test results and the resultant intermetallic formed. The study will attempt to produce level 1, level 2, and level 3 corrosion as denoted by IPC-4552 rev A and tabulate wetting balance results and congruity of intermetallic formed.
Technical Library | 2012-11-27 14:06:48.0
Quality managers and line supervisors are routinely tasked with the responsibility of ensuring that the hand soldering process is under control. The method most commonly used is to measure the idle tip temperature of the soldering station and to use this reading as a benchmark of system compliance. This method, although popular is now being seriously questioned by many industry professionals as being irrelevant in qualifying true system process control. This document aims to present a practical view of what factors are important for successful hand soldering and to suggest an alternative procedure for qualification that is simple, repeatable and directly related to the effectiveness of the soldering station.
Technical Library | 2023-04-17 21:17:59.0
The purpose of this paper is to evaluate and compare the effectiveness and sensitivity of different cleanliness verification tests for post soldered printed circuit board assemblies (PCBAs) to provide an understanding of current industry practice for ionic contamination detection limits. Design/methodology/approach – PCBAs were subjected to different flux residue cleaning dwell times and cleanliness levels were verified with resistivity of solvent extract, critical cleanliness control (C3) test, and ion chromatography analyses to provide results capable of differentiating different sensitivity levels for each test. Findings – This study provides an understanding of current industry practice for ionic contamination detection using verification tests with different detection sensitivity levels. Some of the available cleanliness monitoring systems, particularly at critical areas of circuitry that are prone to product failure and residue entrapment, may have been overlooked. Research limitations/implications – Only Sn/Pb, clean type flux residue was evaluated. Thus, the current study was not an all encompassing project that is representative of other chemistry-based flux residues. Practical implications – The paper provides a reference that can be used to determine the most suitable and effective verification test for the detection of ionic contamination on PCBAs. Originality/value – Flux residue-related problems have long existed in the industry. The findings presented in this paper give a basic understanding to PCBA manufacturers when they are trying to choose the most suitable and effective verification test for the detection of ionic contamination on their products. Hence, the negative impact of flux residue on the respective product's long-term reliability and performance can be minimized and monitored effectively.
Technical Library | 2007-03-08 19:31:10.0
Reflow profile has significant impact on solder joint performance because it influences wetting and microstructure of the solder joint. The degree of wetting, the microstructure (in particular the intermetallic layer), and the inherent strength of the solder all factor into the reliability of the solder joint. This paper presents experimental results on the effect of reflow profile on both 63%Sn 37%Pb (SnPb) and 96.5%Sn 3.0%Ag 0.5%Cu (SAC 305) solder joint shear force.
Technical Library | 2022-10-11 20:15:14.0
The increased temperatures associated with Pb-free processes have produced significant challenges for PWB laminates. Newly developed laminates have different curing processes, are commonly filled with ceramic particles or micro-clays and can have higher Tg values. These changes which are aimed at improving the materials resistance to thermal excursions and maintaining electrical integrity through primary attach and rework operations have also had the effect of producing harder resin systems with lower fracture toughness.
Technical Library | 2009-03-19 20:23:54.0
Over the past several years, post-reflow defluxing of circuit assemblies has gained in popularity. Microminiaturization of components and boards, combined with higher expected reliability and increased product liability, have contributed to the prominence of defluxing. Lead-free solder paste - with its higher reflow temperatures and negative effects on flux - increase the likelihood of post-reflow defluxing to increase a product's reliability and aesthetic appearance.
Technical Library | 2009-07-29 16:33:01.0
While the origin of the phrase "may you live in interesting times" is widely disputed, the fact that we indeed live in an interesting time is certainly not. While record bank failures and declines in stock values, only rivaled by the Depression era, wreak havoc on consumer confidence, the economic trickle-down effect translates to reductions in production output and ultimately the consolidation of many industries, including electronic assembly.
Technical Library | 2012-12-14 14:17:56.0
This article provides practical and affordable Design-for- Test (DFT) and Design-for-Inspection (DFI) methods that will have a positive impact on product costs, yield, reliability, and time-to-market. The properties of testability (including controllability and observability) will be analysed as they relate to analogue and digital design rules and their cause/effect, as well as the electrical and physical characteristics of proper PCB design.
Technical Library | 2019-08-09 00:06:36.0
Working with SCADA systems when not properly trained and qualified can be almost as dangerous as working with PLCs without proper PLC training. Some times it can be even more costly to a company. This article explains the best way to learn SCADA systems, also the most cost-effective way! Read to learn how to select the best, what to look for in a SCADA course.
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.
