Technical Library | 2020-03-09 10:50:17.0
A customer called the Helpline seeking advice for cleaning no-clean fluxes prior to applying a conformal coating. The customer's assemblies were manufactured with a no-clean rosin based solder paste (ROL0) and were cleaned with an isopropyl alcohol (IPA) wash. After cleaning, a white residue was sometimes found in areas with high paste concentrations and was interfering with the adhesion of the conformal coating (Figure 1). For conformal coatings to adhere properly, the printed circuit board (PCB) surface must be clean of fluxes and other residues. In addition, ionic contamination left by flux residues can lead to corrosion and dendrite growth, two common causes of electronic opens and shorts. Other residues can lead to unwanted impedance and physical interference with moving parts.
Technical Library | 2023-09-13 13:10:06.0
Pneumatic stencil cleaning machines are a great way to improve the efficiency and effectiveness of your stencil cleaning process. These machines use compressed air to remove contaminants and debris from stencils, which can cause defects and reliability issues.
Technical Library | 2023-09-13 12:46:41.0
Online PCBA cleaning machines are a great way to improve the quality and reliability of your printed circuit boards (PCBs). These machines use a variety of methods to remove contaminants and debris from PCBs, including water, solvents, and ultrasonic waves.
Technical Library | 2023-09-13 13:07:16.0
Pneumatic stencil cleaning machines are a great way to improve the efficiency and effectiveness of your stencil cleaning process. These machines use compressed air to remove contaminants and debris from stencils, which can cause defects and reliability issues.
Technical Library | 2023-09-13 13:03:25.0
SMT auto aqueous stencil cleaning machines are an essential tool for any SMT production line. These machines use a variety of methods to remove contaminants and debris from SMT stencils, which can cause defects and reliability issues.
Technical Library | 2023-04-17 21:37:32.0
Ionic contamination is a leading cause in the degradation and corrosion of electronic assemblies, leading to lifetime limitation and field failure (Fig. 1). Ionic residue comes from a variety of sources shown in Fig. 2 opposite: Examples of ionic contaminants: * Anions * Cations * Weak Organic Acid
Technical Library | 2010-06-10 21:01:48.0
This paper researches the effectiveness of the R.O.S.E. cleanliness testing process for dissolving and measuring ionic contaminants from boards soldered with no-clean and lead-free flux technologies.
Technical Library | 2018-11-29 13:43:54.0
Ionic contamination testing as a process control tool a newly developed testing protocol based on IPC-TM 650 2.3.25, was established to enable monitoring of ionic contamination within series production. The testing procedure was successfully implemented within the production of high reliability, safety critical electronic circuits, involving multiple production sites around the world. I will be shown in this paper that the test protocol is capable for meeting Six-Sigma-Criteria.
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 | 2016-09-08 16:27:49.0
In this investigation a test matrix was completed utilizing 900 electrodes (small circuit board with parallel copper traces on FR-4 with LPI soldermask at 6, 10 and 50 mil spacing): 12 ionic contaminants were applied in five concentrations to three different spaced electrodes with five replicas each (three different bare copper trace spacing / five replications of each with five levels of ionic concentration). The investigation was to assess the electrical response under controlled heat and humidity conditions of the known applied contamination to electrodes, using the IPC SIR (surface insulation resistance) J-STD 001 limits and determine at what level of contamination and spacing the ionic / organic residue has a failing effect on SIR.
