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In electronics, printed circuit boards, or PCBs, are used to mechanically support electronic elements which have their connection leads soldered onto ISO 9001 Accreditation Consultants copper pads in surface area install applications or through rilled holes in the board and copper pads for soldering the element leads in thru-hole applications. A board design might have all thru-hole parts on the top or component side, a mix of thru-hole and surface mount on the top only, a mix of thru-hole and surface mount parts on the top and surface area install elements on the bottom or circuit side, or surface area mount parts on the top and bottom sides of the board.

The boards are likewise used to electrically connect the required leads for each element using conductive copper traces. The component pads and connection traces are engraved from copper sheets laminated onto a non-conductive substrate. Printed circuit boards are designed as single sided with copper pads and traces on one side of the board just, double sided with copper pads and traces on the leading and bottom sides of the board, or multilayer designs with copper pads and traces on top and bottom of board with a variable variety of internal copper layers with traces and connections.

Single or double sided boards consist of a core dielectric product, such as FR-4 epoxy fiberglass, with copper plating on one or both sides. This copper plating is etched away to form the actual copper pads and connection traces on the board surface areas as part of the board production process. A multilayer board consists of a number of layers of dielectric product that has actually been impregnated with adhesives, and these layers are used to separate the layers of copper plating. All of these layers are aligned and then bonded into a single board structure under heat and pressure. Multilayer boards with 48 or more layers can be produced with today's technologies.

In a common four layer board style, the internal layers are frequently used to supply power and ground connections, such as a +5 V aircraft layer and a Ground airplane layer as the 2 internal layers, with all other circuit and element connections made on the leading and bottom layers of the board. Really intricate board styles may have a large number of layers to make the numerous connections for various voltage levels, ground connections, or for connecting the numerous leads on ball grid variety gadgets and other big incorporated circuit plan formats.

There are usually 2 kinds of material used to construct a multilayer board. Pre-preg material is thin layers of fiberglass pre-impregnated with an adhesive, and remains in sheet form, normally about.002 inches thick. Core material is similar to a really thin double sided board because it has a dielectric product, such as epoxy fiberglass, with a copper layer deposited on each side, generally.030 density dielectric product with 1 ounce copper layer on each side. In a multilayer board design, there are 2 approaches utilized to build up the preferred variety of layers. The core stack-up approach, which is an older technology, utilizes a center layer of pre-preg material with a layer of core material above and another layer of core material below. This combination of one pre-preg layer and two core layers would make a 4 layer board.

The movie stack-up technique, a newer technology, would have core material as the center layer followed by layers of pre-preg and copper product developed above and below to form the final number of layers required by the board design, sort of like Dagwood building a sandwich. This method allows the maker flexibility in how the board layer thicknesses are combined to meet the ended up product density requirements by differing the number of sheets of pre-preg in each layer. When the material layers are completed, the entire stack is subjected to heat and pressure that triggers the adhesive in the pre-preg to bond the core and pre-preg layers together into a single entity.

The process of manufacturing printed circuit boards follows the actions below for many applications.

The process of figuring out products, procedures, and requirements to meet the client's specifications for the board style based upon the Gerber file details offered with the order.

The process of transferring the Gerber file data for a layer onto an etch withstand film that is placed on the conductive copper layer.

The traditional procedure of exposing the copper and other areas unprotected by the etch resist film to a chemical that removes the unprotected copper, leaving the secured copper pads and traces in place; newer procedures use plasma/laser etching instead of chemicals to remove the copper product, allowing finer line definitions.

The procedure of aligning the conductive copper and insulating dielectric layers and pressing them under heat to activate the adhesive in the dielectric layers to form a solid board product.

The procedure of drilling all the holes for plated through applications; a 2nd drilling procedure is used for holes that are not to be plated through. Details on hole location and size is consisted of in the drill drawing file.

The procedure of applying copper plating to the pads, traces, and drilled through holes that are to be plated through; boards are positioned in an electrically charged bath of copper.

This is needed when holes are to be drilled through a copper area but the hole is not to be plated through. Avoid this procedure if possible because it adds cost to the ended up board.

The process of applying a protective masking material, a solder mask, over the bare copper traces or over the copper that has actually had a thin layer of solder applied; the solder mask secures against environmental damage, offers insulation, protects against solder shorts, and protects traces that run between pads.

The process of covering the pad areas with a thin layer of solder to prepare the board for the ultimate wave soldering or reflow soldering process that will happen at a later date after the components have actually been positioned.

The procedure of applying the markings for component designations and element lays out to the board. May be applied to just the top or to both sides if parts are mounted on both leading and bottom sides.

The procedure of separating several boards from a panel of identical boards; this process also enables cutting notches or slots into the board if required.

A visual assessment of the boards; also can be the procedure of inspecting wall quality for plated through holes in multi-layer boards by cross-sectioning or other techniques.

The process of looking for continuity or shorted connections on the boards by means using a voltage between numerous points on the board and identifying if an existing flow takes place. Depending upon the board intricacy, this process might require a specially developed test component and test program to integrate with the electrical test system utilized by the board producer.