Technical Library | 2020-06-02 15:16:51.0
A commercial systems manufacturer working on a major defense program contacted the Helpline for urgent assistance with an issue of failed parts during reliability testing. They were attempting to incorporate commercial off-the-shelf (COTS) computer-related hardware into a battlefield system and were experiencing reliability issues. It was noted that the parts were labeled by the vendor as "compliant to military (or MIL) standards" but not clearly identified as tin-lead or lead-free. ACI Technologies has supported a number of customers with lead-free issues and we assisted the customer in developing a short term and long-term solution to their problem.
Technical Library | 2019-10-21 09:58:50.0
An ACI Technologies customer inquired regarding printed circuit board(PCB) failures that were becoming increasingly prevalent after the SMT (surface mount technology) manufacturing process. The failures were detected by electrical testing, but were undetermined as to the location and specific devices causing the failures. The failures were suspected to be caused predominately in the BGA (ball grid array) devices located on specific sites on this 16 layer construction. Information that was provided on the nature of the failures (i.e., opens or shorts) included high resistance shorts that were occurring in those specified areas. The surface finish was a eutectic HASL (hot air solder leveling) and the solder paste used was a water soluble Sn/Pb(tin/lead).
Technical Library | 2019-06-19 11:06:46.0
Tin (Sn) metal displays the characteristic of growing “tin whiskers” from pure tin coatings (most actively on relatively thin, electrodeposited or immersion tin coatings), usually months or years from the initial deposition of the tin. Tin whiskers are electrically conductive, filamentary, single crystals of white (beta phase) tin. These filaments of single crystal tin are usually one to five microns in diameter, and a few microns up to several tens of millimeters long, that grow spontaneously from the tin coatings. Alloying additions of several percent (by weight) of lead (Pb) prevents these electrically conductive tin whiskers from growing. Pb alloyed into the Sn was discovered to prevent the occurrence of tin whiskers in electronic assemblies in the 1950s as the Bell Laboratories solution to the problem of tin whiskers. The alloying of the tin with lead has thus quietly averted incalculable losses from short circuits in electronic equipment for the last 60 years.
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 | 2023-11-14 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 | 2010-11-16 12:06:38.0
The Net Tie is a component type which allows for shorting together various nets in a design. The graphic for the symbol can be as simple as two component pins representing a virtual component between nets or as complex as mutipul pins (as many as desired)
Technical Library | 2017-10-12 15:45:25.0
The risk associated with whisker growth from pure tin solderable terminations is fully mitigated when all of the pure tin is dissolved into tin-lead solder during SMT reflow. In order to take full advantage of this phenomenon, it is necessary to understand the conditions under which such coverage can be assured. A round robin study has been performed by IPC Task group 8-81f, during which identical sets of test vehicles were assembled at multiple locations, in accordance with IPC J-STD-001, Class 3. All of the test vehicles were analyzed to determine the extent of complete tin dissolution on a variety of component types. Results of this study are presented together with relevant conclusions and recommendations to guide high reliability end-users on the applicability and limitations of this mitigation strategy.
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 | 2020-08-13 01:12:57.0
The solar industry has driven solutions that result in electronics systems that are required to perform in outside environments for over 25 years. This industry expectation has resulted in solutions to protect the electronics from failure that can result from interaction with moisture, and various chemicals leading to corrosion and shorting of the systems. Potting and encapsulation compounds can impart the very high level of protection from environmental, thermal, chemical, mechanical, and electrical conditions that the solar applications demand.
Technical Library | 2019-05-29 01:47:22.0
1.Vias near SMD pads: Solder can flow into the via after melted. As a result cold joint will appear in the end. Check the picture below. 2.Vias on SMD pads: Solder can flow into the via more easier after melted. Check the picture below. 3.Via opening without soldermask covered. When workers solder TH parts by hand, soldering iron can touch vias sometime, then tiny amounts molten solder will stay on vias. This can lead to electrical short easily. We recommend you make all vias tenting (covered by solder mask) if it is possible.
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