Tuesday, July 21, 2009

PC Board Fabrication

PC board fabrication involves two aspects, namely:

* designing of circuit diagram
* inlaying it over the surface of the board

With the availability of high-tech machines, PC board fabrication has become simpler and economical.

Steps in PC Board Fabrication

Typically, PC board fabrication comprises the following steps:

Preparing artwork: This involves:

* preparing a basic circuit diagram on white paper.
* A conventional style is to use thin felt-tip pen, specially designed stencils or auto transferable stickers to prepare circuit diagram.
* Today’s contemporary style involves using CAD technology through specifically made software.
* CAD has simplified the designing process along with reduction in time.

Transporting design: At this stage, the artwork design is transferred onto the circuit board. A variety of techniques are used, such as:

* manual designing over the metal surface using a felt-tip pen.
* using self-adhesive films that are placed on the board’s surface.
* the use of photo-sensitive spray.
* employing special photo-sensitive circuit boards as such PC boards are expensive but have uniform photo sensitivity that facilitate high quality design transport.

Exposure to UV rays: The circuit board is then placed in a specially-designed box to get exposed to UV rays. A thin UV stream of 125W is used for this purpose. Following stages are:

* UV exposure transfers the circuit diagram onto the photo-sensitive plate.
* This stage requires specialist supervision to define the time of exposure.
* Later, the board is chemically treated with a mixture of caustic soda and water.
* It helps to remove the photographic film from the board and you get a printed circuit board with the circuit design inlaid.

Etching: The technique of plating copper on the surface of the circuit boards to form charge flow route is called as etching. Unwanted deposition of copper is chemically removed. The circuit board is then coated with a solder paste which brings forth a green color.

Drilling: This involves:

* making holes, called as vias, onto the circuit board.
* Vias allows for soldering of the electrical components.

World over, most of the large scale PC board fabrication is done through automated processes. US-based PNC Inc. excels in the manufacturing and repairing of PC boards. By producing double-sided and multiple circuit boards, PNC Inc has pursued excellence as its endeavor to meet client requirements.

Circuit Board

Dating back to its successful stint during the World War II, the Circuit board has traveled a long way as it is used even in space crafts and satellites. Invented by Paul Eisler, its manufacturing stayed under military control till the 1930s. Its popularity grew by the end of the war.

Traditionally, its components were connected on the board via wiring but modern boards have inlaid copper threads for effective connection. Other facts about circuit boards are that:

* they are critical components for electrical appliances.
* they act as a base plate where circuit components can be mounted for electrical connections.
* they help to organize electronic circuitry.
* they help to conserve energy.

Types of Circuit Boards

Electronic circuit boards are divided into two broad categories, namely those used for experimental purposes and those for commercial or industrial usage. However, the following three types of circuit boards are worth considering as they are easily available in the market:

Breadboard: This is useful in many ways such as:

* It serves the purpose of testing by making temporary circuits.
* A breadboard does not require soldering to fix the components on this board.
* It is a cost-effective alternative to professional boards.
* It can be re-used multiple times to make test circuits.

Stripboard: These boards, with their large number of holes to facilitate ease of connection, are used for the following purposes:

* to make permanent soldered circuits with high durability.
* as an ideal choice for circuits with 2 or 3 ICs.
* to act as a conductive base due to its copper plating on one side.
* Components are placed on the non-copper side and soldered to the copper tracks.

Printed circuit board (PCB): Also known as a printed wiring circuit board, the PCB has the following features and uses:

* It comprises a base plate of non-conducting material such as glass fibers.
* Copper is enameled over both the sides to allow the flow of charge.
* PCBs are specifically prepared for each circuit diagram.
* Each circuit diagram is chemically pasted on either side of the plate.
* The board is then treated with acid to remove copper deposition.
* The resultant of this process is a circuit board with inlaid circuit diagram and copper threads.
* Lastly, a protective metal layer is coated on both sides to avoid copper corrosion.

By manufacturing printed circuit boards since 1968, PNC Inc offers a variety of printed circuit boards with the latest technology in place.

Thursday, July 9, 2009


There are two major methods for drilling the first and most prominent is by drill bits and secondly by laser. Drill bits is by far the most used method.

The Drilling Process

Drilling is a critical operation as it starts the interconnect process. If holes are not properly drilled there can a major problem that may not be recognized until electrical test.
A customer provides a drill file, which has location and size. The size is adjusted to allow for plating.

The boards are stacked (stack height depends on drill size and board thickness) and are pinned together.

The program is loaded into the drill machine along with the required drills, and the panels.

The machine then drills all the required holes in the proper location.

There are certain items when considering the drill process, the feed rate of the drill which is how fast the drill will go down into the stack of boards and the speed, which is how fast the drill will spin or RPMs.

The last but by far not the least is the drill bit itself.

Drill bits are very important, they are often resharpened two or more times. This process, if not performed properly, can lead to defective drills which in turn can cause poor hole condition.

For more information on drilling or other processes please visit our website at www.pnconline.com

Computer Aided Design / Computer Aided Manufacturing (CAD/CAM)

CAD and CAM are the first step when first steps when building a printed circuit. CAD is used by the customer of the PCB manufacturer to create the layout of the printed circuit board (PCB). The manufacturer uses CAM software to create all the files necessary to manufacture the PCB

How CAD/CAM Works

CAD primarily is derived from the schematic of the circuit board, and then changes are made as required. The product of the CAD software is then loaded into the CAM software and is checked for manufacturability.


PNC, Inc. uses the state of the art software for the CAM operation; Advantages of us a CAM process over traditional methods are many. Accuracy being the biggest advantage, many hours are saved by the use of electronic files. Design rules can be used to assure that certain parameters are always met. For more information on CAD/CAM or any other process please visit www.pnconline.com