Descriptions

This section gives definitions/descriptions of different terms
and processes used in the circuit board fabrication.

Definitions:

Board Size –
Physical dimensions of the board including length, width, and thickness. Typical sizes are 3 x 5 inches by 1/16 inch thick.

Trace Width – Width of the copper wires (traces) that will be on your PCB.

Trace pitch – Distance between adjacent copper traces on your PCB.

# of Layers – Number of metal layers in your PCB. Most boards have 1 single layer of metal which is on the top. Some boards have 2 layers (one on each side), or multiple layers sandwiched within the board itself.

Substrate – Material which separates and insulates metal layers. It can vary in thickness and be made of various materials. Typical board substrates are made of an epoxy named “FR-4”. Other materials include ceramic.

Trace Metal – Type of metal layer which is used on the board. Typical metal layers are made of copper. Other materials include gold, silver, aluminum, titanium, and tungsten.

Trace Thickness – Thickness of the metal layers. It is usually measured by the weight of metal layer. Typical thicknesses are 1 – 2 oz.

Gold Fingers – Card-edge connector with gold plated traces which are found on board devices such as PCI cards.

Number of Parts – This is the number of components such as IC’s, resistors, and capacitors which will be soldered to your PCB.

Type of Parts – This is the way your components will be connected to your PCB. The two primary methods include through-hole and surface-mount connections. Through-hole is the easiest hand-soldering method by which component leads are fed though the PCB with solder connections on each side. Surface-mount is a more difficult hand-soldering method by which component leads attach directly to one surface of the PCB.

Component Pin Pitch – Distance between adjacent component leads

Hole Diameter – Diameter of holes which will be drilled through the PCB for mounting or component connections.

# of Drill Holes – Number of holes which will be drilled in your PCB.

Turn-Around Time – The amount of time it will take in order to complete fabrication of a PCB either by DIY or commercial methods.

Quantity of Boards – The number of boards which need to be fabrication. Either identical or different circuit designs.

Soldermask – The greenish coating which is typically seen on many commercial circuit boards. It is used as a protective coating.

Silkscreen – This is the lettering that is visible on the surface of a PCB.

Soldering Method – Method in which components are connected to the metal contacts and traces of the PCB. Many individuals have access only to hand-held soldering irons. Other commercial methods exist such as waveflow soldering or reflow oven soldering.

Through Hole Plating (THP) – This is a method of plating the interior of a hole with a conductive material. THP connects different layers together and eases soldering parts.

Budget – Amount of money available to be spent on fabrication costs.