Printed circuit boards (PCB) are of 2 types dependant upon their substrates – rigid printed circuit boards and flexible printed circuit boards.
The PCBs of yesterday were mostly rigid. With this modern era of mobile technology where everybody is inching toward miniaturization, a requirement was felt for circuit boards that were lightweight, flexible, thin, small, and had high wiring density. Flexible printed circuit boards were invented to resolve these requirements. These are Rigid-Flex PCB that can be three-dimensionally wired and might be reshaped to match available space.
A flexible PCB is composed of a flexible type of board, wirings provided in the flexible board, and connection pads being conductive through wirings, that happen to be provided about the edge of the flexible board. A copper foil is laminated to your resin substrate the layers and joined with adhesive or with the effective use of heat and pressure into an important board. There can be several conductive layer to make circuitry for both sides. You will find insulating layers, adhesive layers, and encapsulating layers between your conductive layers to make sure sufficient insulation. The plastic substrate of flexible printed circuit boards is formed of polyimide or similar thermoplastic material, for example polyetherimide.
The substrate will then be coated with an adhesive and contains a cable by using a plurality of embedded electrically conductive lines. Apertures may be formed at one of the insulation layers for electrical link with other electronic components. Electronic devices are then connected to one another. Generally speaking, the front and back surfaces of them are covered with insulating layers to prevent a wiring pattern from being conducted for some other wiring pattern formed on Flexible printed circuit boards.
* Take thin polyimide sheets which are copper plated for both sides. Cut the sheet to the required size. Ensure that the copper is not smudged and also the edges of your sheet are not uneven, that may harm the printer later.
* Take a solid ink printer that prints in melted wax. Wax forms a layer in the copper that protects it later while etching.
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Use Computer Aided Design (CAD) software to attract a diagram of your respective circuit.
* Take advantage of the printer to print this design in the polyimide sheet. The printed areas may come up as copper traces. Use dark, easily distinguishable colors, including black or magenta.
* Soak the printed polyimide sheet in ferric chloride. We have been now in the stage called etching, wherein ferric chloride can be a copper etchant. It may take up to around 30 minutes for your dexbpky07 traces to dissolve along with the polyimide to indicate up.
* The circuit has become ready for mounting. You are able to work into smaller circuits if required or make use of it since it is. Holes are drilled with laser to mount electronic components. The Flexible Circuits is now ready to solder.