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 | 2019-09-27 09:14:41.0
One of the most critical factors in preventing corrosion from occurring in electronics is maintaining the state of cleanliness. This is not an easy feat to achieve. Corrosion is defined as the deterioration of a material or its properties due to a reaction of that material with its chemical environment. [1] So, to prevent corrosion from occurring, either the material or the chemical environment must be adjusted. Adjusting the material usually means application of a protective coating or replacing a more reactive material with a less reactive material. Adjusting the chemical environment usually means removing ionic species through cleaning, and removing moisture, usually with a conformal coating or hermetic package. Ionic species and moisture are problematic because they form an electrolyte which is able to conduct ions and electricity. Any metal that comes into contact with the electrolyte can begin to corrode.
Technical Library | 2023-12-06 03:28:49.0
Mastering Precision: I.C.T's SMT Conformal Coating Valves Introduction Of SMT Conformal Coating Valves: In various industries, including electronics, lighting, energy, and life sciences, the SMT conformal coating process plays a critical role. Precision is key, and the choice of a SMT coating valve significantly influences application quality. This article explores I.C.T's SMT conformal coating valves, focusing on the C-0101, C-L101, PJ-01, PJ-01 (with plastic bucket), C-0100, D-0100, D-0300, and the W Series. C-0101 Water Curtain Spray SMT Conformal Coating Valves: The C-0101, a non-atomizing water curtain spray valve, excels with low-viscosity solvent materials. It ensures clean and precise edges in applications like conformal coatings, UV adhesives, backfilling, and volatile substances. C-L101 Rotary Water Curtain Spray Valve: Similar to the C-0101, the C-L101 suits low-viscosity solvent materials, offering a precise edge without splashing for various coatings. PJ-01 Injection Valve (Without Plastic Bucket): Designed for high-precision applications in electronics, lighting, energy, and life sciences, the PJ-01 excels in accurate dispensing and coating. It accommodates various materials, including red glue, liquids, and pastes. PJ-01 Injection Valve (With Plastic Bucket 30CC): The PJ-01, with a 30cc plastic bucket, maintains high precision for complex circuit board applications, offering precise dispensing for materials like red glue, liquids, and pastes. C-0100 Non-Rotating Film Valve: Different from pneumatic atomizing valves, the C-0100 provides precise edge definition without air pressure involvement. It addresses issues related to atomizing drift and fast-drying adhesives, allowing control over the film width. D-0100 Precision Valve: The D-0100, with a unique fluid-sealing structure driven by compressed air, minimizes seal replacement frequency. Suitable for various fluid dispensing, it handles UV adhesives, encapsulating materials, silicones, epoxies, and surface coatings. D-0300 Dispensing Valve: Tailored for precision fluid dispensing at low driving pressure, the D-0300 accommodates a range of materials, including acrylics, silicones, epoxies, and UV adhesives. It's ideal for applications where accuracy and consistency are crucial. W Series: Needle Design Atomization Valves: The W Series offers needle design valves leaving zero residue. Easy to clean without disassembly, they provide adjustable fluid and air pressure for various coating materials, ensuring excellent atomization effects. Analyzing The Options: When selecting a conformal coating valve, consider specific application requirements. C-0101 and C-L101 suit low-viscosity solvent materials, providing clean and precise edges. PJ-01, with or without a plastic bucket, offers high-precision dispensing for complex applications. C-0100 and D-0100 are versatile for various materials, and D-0300 excels in precision dispensing. The W Series offers residue-free needle design atomization valves. Choose based on material, precision, and coating needs. Integration with I.C.T's Conformal Coating Machines: Integral to I.C.T's Conformal Coating machines, these valves enable precise application tailored to specific requirements. Machines like I.C.T-T550, I.C.T-T550U, I.C.T-T600, and I.C.T-T650 come equipped with a range of valve options catering to diverse production line needs. I.C.T SMT Coating Machine.png Conclusion: Selecting the right conformal coating valve is crucial for consistent, high-quality results. Evaluate options based on material, precision, and coating requirements. I.C.T provides tailored solutions for electronic assembly needs. For detailed insights into coating and dispensing machines, follow the provided link. Professional engineers are ready to assist in designing a production line that perfectly matches your requirements, ensuring optimal performance. Contact us for more information and tailored solutions to elevate your conformal coating processes.
Technical Library | 2019-05-21 17:31:39.0
In the field of electronics manufacturing, the end use of the product will always dictate the processes, procedures, and methods, not only for building the product, but also for testing, cleaning, and protecting the assembly in order to assure the level of quality required for proper operation. The need to protect an electronic assembly from its end use environment may stem from anyone of a number of hazardous (or potentially hazardous) conditions. Choosing the type of protective material is dependent upon matching that material’s characteristics with the conditions to be overcome. Naturally, the use of a protective (conformal) coating will require some method of verification to ensure the desired level and type of protection is achieved.
Technical Library | 2019-05-23 10:42:00.0
Why identify flux residues? The primary purpose of flux is to reduce species of metal oxides from solderable surfaces, and to act as a mechanism for lifting and removing debris. If the assembly is not properly cleaned after manufacturing, flux may continue to reduce metals and may eventually corrode the assembly. When the assembly is powered, the metal ions may precipitate along electromagnetic field lines and form dendritic shorts. In addition, the presence of residue can alter the insulation properties of a board, affect the adhesion of the conformal coating, or interfere with the moving parts of the assembly. In radio frequency (RF) applications, flux may change the RF properties on the surface of the printed circuit board (PCB) such as the dielectric strength, surface resistance, and Q-resonance.
Technical Library | 2015-03-04 10:56:26.0
As the proliferation of modern day electronics continues to drive miniaturization and functionality, electronic designers/assemblers face the issue of environmental exposure and uncommon applications never previously contemplated. This reality, coupled with the goal of reducing the environmental and health implications of the production and disposal of these devices, has forced manufacturers to reconsider the materials used in production. Furthermore, the need to increase package density and reduce costs has led to the rapid deployment of leadless packages such as QFN, POP, LGA, and Micro-BGA. In many cases, the manufacturers of these devices will recommend the use of no clean fluxes due to concerns over the ability to consistently remove flux residues from under and around these devices. These concerns, along with the need to implement a tin whisker mitigation strategy and/or increase environmental tolerance, have led to the conundrum of applying conformal coating over no clean residues.
Technical Library | 2017-12-11 22:31:06.0
Typical printed circuit board assemblies (PCBAs) processed by reflow, wave, or selective wave soldering were analysed for typical levels of process related residues, resulting from a specific or combination of soldering process. Typical solder flux residue distribution pattern, composition, and concentration are profiled and reported. Presence of localized flux residues were visualized using a commercial Residue RAT gel test and chemical structure was identified by FT-IR, while the concentration was measured using ion chromatography, and the electrical properties of the extracts were determined by measuring the leak current using a twin platinum electrode setup. Localized extraction of residue was carried out using a commercial C3 extraction system. Results clearly show that the amount and distribution of flux residues are a function of the soldering process, and the level can be reduced by an appropriate cleaning. Selective soldering process generates significantly higher levels of residues compared to the wave and reflow process. For conformal coated PCBAs, the contamination levels generated from the tested wave and selective soldering process are found to be enough to generate blisters under exposure to high humidity levels.
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