Oavsett typ av skydd som efterstr\u00e4vas m\u00e5ste alla kretskort reng\u00f6ras noggrant f\u00f6r att s\u00e4kerst\u00e4lla att ytf\u00f6roreningar inte p\u00e5verkar skyddsniv\u00e5erna fr\u00e5n bel\u00e4ggningen eller hartset.<\/p>\n\n\n\n A conformal coating is a thin film that can be applied to a PCB to offer protection from hazardous environments. Such coatings offer effective chemical and thermal resistance for short exposures. They \u201cconform\u201d to the contours of a board allowing for excellent protection and a thorough coverage to extend the working life of the PCB. Encapsulation resins are designed to protect and insulate PCBs and components from harsh and challenging environments by encapsulating the device and creating a barrier. When applied to PCBs resins can be 0.5 mm + thick, often being applied much more thickly than this. As a result, resins can cause a significant increase in weight often resulting in a higher price per unit than coating. Om kretskortet placeras i en inkapsling som \u00e4r t\u00e4nkt som prim\u00e4rt skydd, r\u00e4cker en skyddsbel\u00e4ggning som reservskydd. Detta \u00e4r perfekt mot skador eller l\u00e4ckage, och kan ge skydd mot fukt och kondens. Om inkapslingen inte kan ge skydd mot milj\u00f6n \u00e4r ett harts ett l\u00e4mpligare val.<\/p>\n\n\n\n Anv\u00e4nds ofta i h\u00f6gsp\u00e4nningselektronik och explosiva milj\u00f6er, hartser ger ett totalt dielektriskt lager f\u00f6r att f\u00f6rhindra ljusb\u00e5gar. I s\u00e5dan milj\u00f6 blir tunnare skyddsbel\u00e4ggningar avsev\u00e4rt mindre effektiva. F\u00f6r k\u00e4nsliga komponenter i milj\u00f6er som kr\u00e4ver begr\u00e4nsade skyddsniv\u00e5er \u00e4r bel\u00e4ggningar sannolikt tillr\u00e4ckliga.<\/p>\n\n\n\n Det \u00e4r viktigt att avg\u00f6ra om kretskortets vikt \u00e4r en faktor i designens slutm\u00e5l. N\u00e4r en bel\u00e4ggning appliceras \u00e4r m\u00e4ngden tillf\u00f6rd vikt minimal, men vid anv\u00e4ndning av harts kan den extra vikten vara avsev\u00e4rd.<\/p>\n\n\n\n F\u00f6r applikationer d\u00e4r omarbetning av kretskortet kan kr\u00e4vas vid ett senare tillf\u00e4lle \u00e4r skyddsbel\u00e4ggningar det mest l\u00e4mpliga valet. Bel\u00e4ggningar kan avl\u00e4gsnas mycket l\u00e4ttare \u00e4n hartser som, n\u00e4r de tas bort, kan f\u00f6rst\u00f6ra kretskortet.<\/p>\n\n\n\n Integrerat f\u00f6r tillverkning och underh\u00e5ll av elektroniska komponenter, \u00e4r Electrolubes produkter idealiska f\u00f6r ett antal industrier inklusive fordonsindustri, industrielektronik, konsumentelektronik och medicinsk sektor. Specialister inom skyddsbel\u00e4ggningar och ingjutningshartser, Electrolube ligger i framkant inom innovation i detta omr\u00e5de.<\/p>\n\n\n\n![\"\"](\"https:\/\/knowhowprod.wpengine.com\/wp-content\/uploads\/2021\/06\/Electrolube-PCB-1.jpg\")
Conformal coatings<\/h2>\n\n\n\n
The thickness of this coating will fall between 25-100 microns, adding a slight increase in weight to the component. As a relatively thin film, this coating applies little stress upon components which is hugely advantageous for delicate and fragile equipment. Typically the film will be transparent, enabling users to identify the PCB beneath with ease.
Most coatings are 1K (single component) systems, offering a long bath life, low curing temperature and short drying time. Reworking the coating and replacing components is simple to do with conformal coatings. Coatings can be applied manually with a paint brush, spray gun or by being dipped. However, increasingly, robotic systems are being used to provide a more precise and consistent application.<\/p>\n\n\n\nEncapsulated resins<\/h2>\n\n\n\n
Resins are typically 2K (two component) systems where a resin and a hardener are mixed to form a cross-linked polymer. Resins have a much higher viscosity than coatings and are designed to cure at room temperature. However, by applying heat to the resin, the cure time can be reduced. As most curing reactions are exothermic, where too much resin is applied the heat produced during the curing process can cause the PCB to overheat and even catch fire.
By using a resin, greater protection can be afforded to the PCB especially in the event of a chemical attack or in scenarios where the component is immersed for longer periods of time. Resins can also offer protection against physical shock as the bulk of the resin can help to dissipate the force. Unlike coatings, resins can be very dark in colour so that when applied, the PCB beneath is completely hidden, creating a degree of security in the design. However, it is worth noting that when resins are removed, this can lead to the destruction of the PCB.<\/p>\n\n\n\nEgenskaper<\/th> Skyddsbel\u00e4ggning<\/th> Harts<\/th><\/tr> Skydd<\/td> L\u00e4gre<\/td> H\u00f6gre<\/td><\/tr> Tjocklek<\/td> 25-100 mikrometer<\/td> 0.5+ mm (ofta mycket tjockare)<\/td><\/tr> Vikt<\/td> Minimal \u00f6kning<\/td> Betydande \u00f6kning<\/td><\/tr> P\u00e5frestning p\u00e5 komponenter<\/td> Mycket lite<\/td> Betydande p\u00e5verkan<\/td><\/tr> Bel\u00e4ggningssystem<\/td> 1K (enkomponent)<\/td> 2K (tv\u00e5komponent)<\/td><\/tr> Omarbetning<\/td> Ja<\/td> Nej<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n Saker att t\u00e4nka p\u00e5 innan du v\u00e4ljer kretskortsskydd<\/h2>\n\n\n\n
1. Inkapslingar<\/h3>\n\n\n\n
2. Milj\u00f6<\/h3>\n\n\n\n
3. Vikt<\/h3>\n\n\n\n
4. Omarbetning<\/h3>\n\n\n\n
Varf\u00f6r Electrolube?<\/h2>\n\n\n\n