Some common finishes include solder, tin, immersion in nickel or gold, silver, carbon etc The final finish depends on the application of the circuit.
Some common insulators include polyimide, polyester, solder mask, polyethylene naphthalene and polyethylene terephthalate.įinishes: Finishes are made to protect the metal surface from oxidation.
Insulators: Insulators are used to separate electrical conductors without conducting current themselves. Some adhesives that are used include epoxy, acrylic or PSAs (Pressure Sensitive Adhesives). Adhesives are used according to the customer needs and thickness of conductor. Copper is the most commonly used conductor while other materials used include aluminum, carbon, silver ink etc.Īdhesives: Adhesives are used for surface mount component binding. Now we will discuss the basic materials used in making flex circuits.Ĭonductors: Conductors allow the electrical current to flow freely. Rigid flex circuits have higher component density. Flex circuits are almost a combination of rigid circuit boards and flex circuits. There are more complex interconnections, layer design surface mounting.Ĥ: Rigid Flex Circuits: In rigid flex circuits the circuits consists of multiple circuit layers connected by an epoxy pre-preg bonding film, almost like a multi-layer flex circuit. The metal layers are again connected by through holes. The two layers are plated by metalized through holes to make connections.ģ: Multi-Layer Flex: Multi-Layer flex circuits has several copper layers separated by dielectric layers. A polyimide overlay is added for insulation and protections from environmental degradation.Ģ: Double Sided Flex: A double sided flex circuit has multiple layers on both sides of a single dielectric layer. The dielectric can be polyimide or polymer. There are many types of flex circuits and here we will discuss the major onesġ: Single Sided Flex: Single sided flex circuits are the most basic and consist of a single layer of metal traces on one side of a dielectric layer. Flex circuits have been in use since the Second World War and they’re applications are still growing exponentially. Flexible circuits are basically made from a thin insulating polymer film with a pattern of conductive traces mounted bonded onto the substrate. Flex circuits can easily be termed as circuits which are flexible or can flex.