Technical Library | 2023-09-15 09:53:02.0
Enhance your electronics manufacturing process with our SMT AOI solution. Achieve superior quality control and product reliability through advanced automated optical inspection technology. Improve production efficiency and reduce defects with our comprehensive AOI solution.
Technical Library | 2024-08-09 06:34:09.0
Quality control in conformal coating applications is vital for ensuring the reliability and longevity of electronic products. Conformal coatings protect printed circuit boards (PCBs) from environmental factors like moisture, dust, and chemicals. To maintain high standards, various inspection methods are employed throughout the coating process. Visual Inspection This is the first line of defense against defects. Inspectors look for uniform coverage, absence of bubbles, and proper curing. Training is essential to ensure that inspectors can identify subtle issues that may affect performance. UV Inspection Most conformal coatings contain a UV tracer, which makes the coating visible under ultraviolet light. UV inspection allows for easy detection of missed areas, ensuring complete coverage. This step is crucial for verifying that the coating has been applied correctly, especially in hard-to-see areas of the PCB. Automated Optical Inspection (AOI) AOI systems offer a more precise and consistent method for inspecting conformal coatings. They use cameras and specialized software to detect defects that might be missed by the human eye. AOI systems can inspect large volumes of PCBs quickly, making them ideal for high-production environments. Thickness Measurement The thickness of the conformal coating is critical for providing adequate protection without affecting the performance of the PCB. Tools such as micrometers, ultrasonic thickness gauges, and eddy current devices are used to measure the coating thickness. Consistent application is key to preventing issues like cracking or insufficient protection. Functional Testing Beyond visual and automated inspections, functional testing is necessary to ensure that the conformal coating does not interfere with the electrical performance of the PCB. This involves subjecting the coated PCB to environmental stress tests, such as thermal cycling, humidity, and salt spray, to assess its reliability in real-world conditions. Process Control and Documentation Implementing strict process controls is essential to maintaining quality. This includes regularly calibrating equipment, training operators, and documenting every step of the process. Proper documentation helps trace issues back to their source and prevents them from recurring. Conclusion Effective quality control in conformal coating applications ensures that PCBs are protected from environmental damage, thereby extending their lifespan and reliability. By employing a combination of visual, UV, and automated inspections, along with thickness measurement and functional testing, manufacturers can achieve the highest standards in coating quality.
Technical Library | 2011-08-18 19:12:04.0
Overview of ESD, Associated Risks and Prevention Measures
Technical Library | 2022-09-25 20:03:37.0
Cracking remains the major reason of failures in multilayer ceramic capacitors (MLCCs) used in space electronics. Due to a tight quality control of space-grade components, the probability that as manufactured capacitors have cracks is relatively low, and cracking is often occurs during assembly, handling and the following testing of the systems. Majority of capacitors with cracks are revealed during the integration and testing period, but although extremely rarely, defective parts remain undetected and result in failures during the mission. Manual soldering and rework that are often used during low volume production of circuit boards for space aggravate this situation. Although failures of MLCCs are often attributed to the post-manufacturing stresses, in many cases they are due to a combination of certain deviations in the manufacturing processes that result in hidden defects in the parts and excessive stresses during assembly and use. This report gives an overview of design, manufacturing and testing processes of MLCCs focusing on elements related to cracking problems. The existing and new screening and qualification procedures and techniques are briefly described and assessed by their effectiveness in revealing cracks. The capability of different test methods to simulate stresses resulting in cracking, mechanisms of failures in capacitors with cracks, and possible methods of selecting capacitors the most robust to manual soldering stresses are discussed.
Technical Library | 2020-02-13 08:41:18.0
Efficient bonding, sealing and potting has a major influence on the sustainable function and safety of electronic components. The key to success here lies in the comprehensive view and control of process engineering. Here it pays to seek collaboration with the systems and the material manufacturer during the very early stages of the project. This is because dispensing systems must be selected for compatibility with the workpiece and the adhesive, sealant or potting compound used. And there are also other factors that play an important role in designing the optimum dispensing system:
Technical Library | 2020-10-27 02:07:31.0
For companies that choose to take the Pb-free exemption under the European Union's RoHS Directive and continue to manufacture tin-lead (Sn-Pb) electronic products, there is a growing concern about the lack of Sn-Pb ball grid array (BGA) components. Many companies are compelled to use the Pb-free Sn-Ag-Cu (SAC) BGA components in a Sn-Pb process, for which the assembly process and solder joint reliability have not yet been fully characterized. A careful experimental investigation was undertaken to evaluate the reliability of solder joints of SAC BGA components formed using Sn-Pb solder paste. This evaluation specifically looked at the impact of package size, solder ball volume, printed circuit board (PCB) surface finish, time above liquidus and peak temperature on reliability. Four different BGA package sizes (ranging from 8 to 45 mm2) were selected with ball-to-ball pitch size ranging from 0.5mm to 1.27mm. Two different PCB finishes were used: electroless nickel immersion gold (ENIG) and organic solderability preservative (OSP) on copper. Four different profiles were developed with the maximum peak temperatures of 210oC and 215oC and time above liquidus ranging from 60 to 120 seconds using Sn-Pb paste. One profile was generated for a lead-free control. A total of 60 boards were assembled. Some of the boards were subjected to an as assembled analysis while others were subjected to an accelerated thermal cycling (ATC) test in the temperature range of -40oC to 125oC for a maximum of 3500 cycles in accordance with IPC 9701A standard. Weibull plots were created and failure analysis performed. Analysis of as-assembled solder joints revealed that for a time above liquidus of 120 seconds and below, the degree of mixing between the BGA SAC ball alloy and the Sn-Pb solder paste was less than 100 percent for packages with a ball pitch of 0.8mm or greater. Depending on package size, the peak reflow temperature was observed to have a significant impact on the solder joint microstructural homogeneity. The influence of reflow process parameters on solder joint reliability was clearly manifested in the Weibull plots. This paper provides a discussion of the impact of various profiles' characteristics on the extent of mixing between SAC and Sn-Pb solder alloys and the associated thermal cyclic fatigue performance.
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Nordson Electronics Solutions makes reliable electronics an everyday reality. Our ASYMTEK, MARCH, and SELECT brands deliver precision fluid dispensing, conformal coating, plasma treatment and selective soldering equipment.
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