Have You Ever Considered Quality Systems

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

The boards are also used to electrically link the required leads for each element using conductive copper traces. The element pads and connection traces are engraved from copper sheets laminated onto a non-conductive substrate. Printed circuit boards are created as single agreed copper pads and traces on one side of the board only, 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 the top and bottom of board with a variable number 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 engraved away to form the real copper pads and connection traces on the board surfaces as part of the board manufacturing procedure. A multilayer board consists of a variety of layers of dielectric product that has actually been fertilized with adhesives, and these layers are utilized to separate the layers of copper plating. All these layers are lined up then bonded into a single board structure under heat and pressure. Multilayer boards with 48 or more layers can be produced with today's innovations.

In a common 4 layer board design, the internal layers are often utilized to supply power and ground connections, such as a +5 V airplane 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 complex board designs may have a large number of layers to make the various connections for various voltage levels, ground connections, or for connecting the many leads on ball grid array gadgets and other big incorporated circuit package formats.

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

The movie stack-up approach, a newer technology, would have core material as the center layer followed by layers of pre-preg and copper material built up above and listed below to form the last variety of layers needed by the board style, sort of like Dagwood constructing a sandwich. This approach permits the producer flexibility in how the board layer densities are integrated to fulfill the ended up product density requirements by differing the variety of sheets of pre-preg in each layer. Once the product layers are finished, 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 procedure of producing printed circuit boards follows the actions listed below for a lot of applications.

The procedure of figuring out materials, processes, and requirements to satisfy the consumer's specs for the board design based upon the Gerber file info supplied with the order.

The process of moving the Gerber file data for a layer onto ISO 9001 Certification Consultants an etch withstand film that is put on the conductive copper layer.

The traditional process of exposing the copper and other locations unprotected by the etch resist movie to a chemical that removes the vulnerable copper, leaving the secured copper pads and traces in location; more recent processes use plasma/laser etching instead of chemicals to remove the copper material, enabling finer line definitions.

The process of lining up the conductive copper and insulating dielectric layers and pushing them under heat to activate the adhesive in the dielectric layers to form a strong board product.

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

The process 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 area however the hole is not to be plated through. Avoid this process if possible due to the fact that it includes cost 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 had a thin layer of solder used; the solder mask secures versus ecological damage, supplies insulation, secures against solder shorts, and protects traces that run between pads.

The procedure of finish 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 process of applying the markings for element classifications and element outlines to the board. Might be used to just the top or to both sides if parts are installed on both leading and bottom sides.

The process of separating multiple boards from a panel of similar boards; this procedure likewise permits cutting notches or slots into the board if needed.

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

The procedure of looking for continuity or shorted connections on the boards by methods applying a voltage in between numerous points on the board and identifying if an existing circulation takes place. Depending upon the board complexity, this process may need a specially designed test fixture and test program to incorporate with the electrical test system used by the board producer.