How You Can Create a Quality Management System Throughout Your Enterprise

In electronics, printed circuit boards, or PCBs, are utilized to mechanically support electronic parts which have their connection leads soldered onto copper pads in surface area mount 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 components on the top or part side, a mix of thru-hole and surface install on the top just, a mix of thru-hole and surface area install elements on the top side and surface install parts on the bottom or circuit side, or surface area install elements on the top and bottom sides of the board.

The boards are also utilized to electrically connect the required leads for each element using conductive copper traces. The part pads and connection traces are engraved from copper sheets laminated onto a non-conductive substrate. Printed circuit boards are created 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 styles with copper pads and traces on top and bottom of board with a variable number of internal copper layers with traces and connections.

Single or double sided boards include 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 real copper pads and connection traces on the board surfaces as part of the board production process. A multilayer board consists of a variety of layers of dielectric product that has actually been impregnated with adhesives, and these layers are utilized to separate the layers of copper plating. All of these layers are lined up and after that 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 typical 4 layer board design, the internal layers are typically used to offer power and ground connections, such as a +5 V aircraft layer and a Ground plane layer as the two internal layers, with all other circuit and part connections made on the top and bottom layers of the board. Extremely intricate board styles might have a a great deal of layers to make the different connections for various voltage levels, ground connections, or for connecting the many leads on ball grid selection gadgets and other large incorporated circuit plan formats.

There are usually 2 types of material utilized to build a multilayer board. Pre-preg material is thin layers of fiberglass pre-impregnated with an adhesive, and is in sheet type, normally about.002 inches thick. Core material resembles an extremely thin double sided board because it has a dielectric material, such as epoxy fiberglass, with a copper layer transferred on each side, typically.030 density dielectric product with 1 ounce copper layer on each side. In a multilayer board style, there are two techniques used to develop the wanted variety of layers. The core stack-up approach, which is an older innovation, uses a center layer of pre-preg material with a layer of core material above and another layer of core material listed below. This mix of one pre-preg layer and 2 core layers would make a 4 layer board.

The film stack-up approach, a more recent technology, would have core product as the center layer followed by layers of pre-preg and copper product built up above and below to form the last number of layers needed by the board design, sort of like Dagwood developing a sandwich. This technique allows the maker versatility in how the board layer thicknesses are combined to satisfy the finished item thickness requirements by varying the variety of sheets of pre-preg in each layer. Once the product layers are completed, the whole stack goes through heat and pressure that causes the adhesive in the pre-preg to bond the core and pre-preg layers together into a single entity.

The procedure of manufacturing printed circuit boards ISO 9001 Certification Consultants follows the steps below for a lot of applications.

The procedure of determining products, procedures, and requirements to meet the customer's requirements for the board style based on the Gerber file info offered with the purchase order.

The procedure of transferring the Gerber file information for a layer onto an etch resist film that is put on the conductive copper layer.

The traditional process of exposing the copper and other locations unprotected by the etch resist film to a chemical that removes the vulnerable copper, leaving the protected copper pads and traces in place; more recent procedures use plasma/laser etching instead of chemicals to eliminate the copper material, allowing finer line definitions.

The process of lining up 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 material.

The procedure of drilling all of the holes for plated through applications; a second drilling process is used for holes that are not to be plated through. Details on hole place 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 placed in an electrically charged bath of copper.

This is required when holes are to be drilled through a copper location but the hole is not to be plated through. Avoid this procedure if possible because it adds expense to the finished board.

The procedure of using a protective masking product, 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 safeguards against environmental damage, supplies insulation, protects versus solder shorts, and protects traces that run between pads.

The procedure of covering the pad locations with a thin layer of solder to prepare the board for the ultimate wave soldering or reflow soldering process that will take place at a later date after the elements have actually been put.

The procedure of applying the markings for element classifications and element outlines to the board. May be applied to just the top or to both sides if components are installed on both top and bottom sides.

The procedure of separating several boards from a panel of identical boards; this procedure likewise allows cutting notches or slots into the board if needed.

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

The procedure of looking for connection or shorted connections on the boards by methods applying a voltage between numerous points on the board and figuring out if a current flow takes place. Depending upon the board complexity, this procedure may need a specially created test fixture and test program to integrate with the electrical test system used by the board producer.