Technical Library | 2017-12-07 10:35:50.0
Electronics manufacturers protect their circuit boards with conformal coatings. Conformal coatings serve as a barrier from environmental hazards and internal shorts, tin whiskers, and corrosion at the board level. Within conformal coatings different material chemistries specialize in shielding from an array of hazards and can be applied by multiple methods. The most common method is atomized spray which disperses the material into a fine mist. Alternatively, non-atomized coating controls the materials' dispense shape while maintaining the original liquid form. While some applications demand atomized spray and other scenarios overlap between atomized and non-atomized coating, this paper focuses on the circumstances where materials are ideally suited for non-atomized, selective coating.
Technical Library | 2023-11-14 02:36:41.0
Understanding In-Circuit Testing (ICT) with PCBA ICT Testing Machine In-Circuit Testing, commonly known as ICT, stands as a sophisticated and precise method within electronics manufacturing. It serves to evaluate the functionality and integrity of individual electronic components on a Printed Circuit Board (PCB). The process employs specialized equipment called ICT Testers, meticulously designed to pinpoint defects, shorts, opens, and other potential issues within the PCB assembly. The Crucial Role of PCBA ICT Testing Machine 1. Quality Assurance ICT is pivotal in ensuring the overall quality and reliability of electronic products. Early identification and rectification of defects in the production process help manufacturers avoid costly recalls, rework, and post-production issues. 2. Cost-Efficiency ICT significantly reduces manufacturing costs by identifying defects at an early stage. This results in fewer defective units reaching the end of the production line, minimizing waste and rework. 3. Faster Time-to-Market Manufacturers can expedite the production process with ICT by swiftly identifying and resolving issues. This leads to faster product launches, providing a competitive edge in the market. Unveiling the Functions of PCBA ICT Testing Machine The ICT Tester, the core of the In-Circuit Testing process, conducts a battery of tests on each PCB, including: 1. Continuity Testing Checks for open circuits, ensuring all connections are properly established. 2. Component Verification Verifies the presence and orientation of components, ensuring alignment with the PCB design. 3. Functional Testing Some ICT Testers execute functional tests, assessing electronic components' performance as per specifications. 4. Short Testing Identifies unintended connections or shorts between different components on the PCB. 5. Insulation Testing Checks for isolation between different circuits, ensuring no undesired connections or paths. 6. Programming and Configuration In some cases, ICT Testers are used to program and configure specific components on the PCB. Advantages of PCBA ICT Testing Machine 1. High Precision ICT offers unparalleled accuracy in defect detection, making it crucial in modern electronics manufacturing. 2. Speed and Efficiency ICT Testers enable rapid testing, allowing manufacturers to assess a large number of PCBs in a short time. 3. Customization ICT Tests can be tailored to suit specific PCB requirements, ensuring thorough evaluation of every design aspect. 4. Data Collection ICT Testers gather valuable data for process optimization and quality control. In-Circuit Testing (ICT) is fundamental in electronics manufacturing, safeguarding product quality, reducing costs, and accelerating time-to-market. The ICT Tester, with its precision and efficiency, positions manufacturers at the forefront of the highly competitive electronics industry. Embracing ICT is not just a choice; it's a necessity for manufacturers striving for excellence in their products. I.C.T is a leading manufacturer of full SMT line machines in the electronic manufacturing industry. Discover how we can enhance product quality, boost performance, and reduce costs. Contact us at info@smt11.com for reliable global supply, unparalleled efficiency, and superior technical service.
Technical Library | 2023-01-10 20:15:42.0
Over the past years there has been consistent growth in the use of electroless nickel / immersion gold (ENIG) as a final finish. The finish is now frequently being used for PBGA, CSP, QFP and COB and more recently gathered considerable interest as a low cost under-bump metallization for flip chip bumping application. One of the largest users for this finish has been the telecommunication industry, were millions of square meters of PCBs with ENIG have been successfully used. The nickel layer offers advantages such as multiple soldering cycles and hand reworks without copper dissolution being a factor. The nickel also acts as a reinforcement to improve through-hole and blind micro via thermal integrity. In addition the nickel layer offers advantages such as co-planarity, Al-wire bondability and the use as contact surface for keypads or contact switching. Especially those pads, which are not covered by solder need a protective coating in corrosive environment – such as high humidity or pollutant gas.
Technical Library | 2015-07-09 17:44:11.0
50,000) number of short duration (
Technical Library | 2023-03-16 19:07:51.0
HISTORY: * In the late 1970s an abrupt unpredictable loss of insulation resistance was observed in PCBs, which were subject to hostile climatic conditions of high relative humidity and temperature while having an applied voltage. * The loss of resistance, even leading to a short circuit was observed to be due to the growth of a subsurface filament from the anode to the cathode. * The term "Conductive Anodic Filamentation" (CAF) was coined.
Technical Library | 2021-04-08 00:30:49.0
As the electronic industry moves to lead-free assembly and finer-pitch circuits, widely used printed wiring board (PWB) finish, SnPb HASL, has been replaced with lead-free and coplanar PWB finishes such as OSP, ImAg, ENIG, and ImSn. While SnPb HASL offers excellent corrosion protection of the underlying copper due to its thick coating and inherent corrosion resistance, the lead-free board finishes provide reduced corrosion protection to the underlying copper due to their very thin coating. For ImAg, the coating material itself can also corrode in more aggressive environments. This is an issue for products deployed in environments with high levels of sulfur containing pollutants encountered in the current global market. In those corrosive environments, creep corrosion has been observed and led to product failures in very short service life (1-5 years). Creep corrosion failures within one year of product deployment have also been reported. This has prompted an industry-wide effort to understand creep corrosion
Technical Library | 2017-07-27 16:51:57.0
Reliability Expectations of Highly Dense Electronic Assemblies is commonly validated using Ion Chromatography and Surface Insulation Resistance. Surface Insulation Resistance tests resistance drops on both cleaned and non-cleaned circuit assemblies. It is well documented in the literature that SIR detects ionic residue and the potential of this residue to cause leakage currents in the presence of humidity and bias. Residues under leadless components are hard to inspect for and to ensure flux residue is totally removed. The question many assemblers consider is the risk of residues that may still be present under the body of components.
Technical Library | 2021-09-29 13:35:21.0
In PCB circuit assemblies the trend is moving to more SMD components with finer pitch connections. The majority of the assemblies still have a small amount of through hole (THT) components. Some of them can't withstand high reflow temperatures, while others are there because of their mechanical robustness. In automotive applications these THT components are also present. Many products for cars, including steering units, radio and navigation, and air compressors also use THT technology to connect board-to-board, PCB's to metal shields or housings out of plastic or even aluminium. This is not a simple 2D plain soldering technology, as it requires handling, efficient thermal heating and handling of heavy (up to 10 kg) parts. Soldering technology becomes more 3D where connections have to be made on different levels. For this technology robots using solder wire fail because of the spattering of the flux in the wires and the long cycle time. In wave soldering using pallets the wave height is limited and pin in paste reflow is only a 2D application with space limitations. Selective soldering using dedicated plates with nozzles on the solder area is the preferred way to make these connections. All joints can be soldered in one dip resulting in short cycle times. Additional soldering on a small select nozzle can make the system even more flexible. The soldering can only be successful when there is enough thermal heat in the assembly before the solder touches the board. A forced convection preheat is a must for many applications to bring enough heat into the metal and board materials. The challenge in a dip soldering process is to get a sufficient hole fill without bridging and minimize the number of solder balls. A new cover was designed to improve the nitrogen environment. Reducing oxygen levels benefits the wetting, but increases the risk for solder balling. Previous investigations showed that solder balling can be minimized by selecting proper materials for solder resist and flux.
Technical Library | 2021-03-10 23:57:29.0
Latent short circuit failures have been observed during testing of Printed Circuit Boards (PCB) for power distribution of spacecraft of the European Space Agency. Root cause analysis indicates that foreign fibers may have contaminated the PCB laminate. These fibers can provide a pathway for electromigration if they bridge the clearance between nets of different potential in the presence of humidity attracted by the hygroscopic laminate resin. PCB manufacturers report poor yield caused by contamination embedded in laminate. Inspections show ...
Technical Library | 2013-02-14 12:54:29.0
Boundary-scan (1149.1) technology was originally developed to provide a far easier method to perform digital DC testing to detect intra-IC interconnect assembly faults, such as solder shorts and opens. Today's advanced IC technology now includes high-speed differential interfaces that include AC or DC coupling components loaded on the printed circuit assembly. Simple stuck-at-high/low test methods are not sufficient to detect all assembly fault conditions, which includes shorts, opens and missing components. Improved diagnostics requires detailed circuit analysis, predictive assembly fault simulation and more complex testing to isolate and accurately detect all possible assembly faults... First published in the 2012 IPC APEX EXPO technical conference proceedings
