Glossary

Active Components:

These are Semiconductor devices, such as transistors, diodes, rectifiers, amplifiers, oscillators, mechanical relays that can change their fundamental properties when placed in a powered electrical circuit, such as amplifiers, rectifiers.

Additive Process:

The circuit pattern is created by the addition of metal not by etching metal away. This process is known as Additive process.

Ambient:

The surrounding atmosphere that comes in contact with the system or component in question.

Analog Circuit:

An electrical circuit that uses continuous time voltages and currents. This is opposite to digital devices where devices states are represented by discrete time and discrete values.

Annular Rings:

Annular ring is the remaining area of a pad after a hole is drilled through the pad. It is a ring of conductive foil and plating material. It is calculated from edge of hole to edge of pad.

The inner and outer layer pads should be at least 0.018″ bigger than the finish hole size (0.010” for vias). If the design has any pad to trace junction minimum requirement, add that to the numbers [0.018″ pad + 0.002″ junction should have 0.020″ pad]. It will give a 9mil annular ring for component pins and 5mil annular ring for vias.

Aperture Information:

Aperture Information is a report that describes the size and shape of each element on the printed circuit boards. This report is also identified as D-code lists. D-code lists are not necessary if your files are saved as Extended Gerber with embedded Apertures (RS274X).

Array:

A collection of elements or circuit boards arranged in rows and columns on a base material.

Assembly:

The procedure of mounting and soldering electrical components on printed circuit boards is known as Printed circuit board assembly. This process can be performed by hand or through specialized equipment. The assembly process requires the use of solder to place the components on the board.

Aspect Ratio:

It is the ratio between the printed board circuit (PCB) thickness and the diameter of the smallest drilled hole. For instance for board thickness 0.031”, the smallest drilled size will be 0.010”.

Automated Test Equipment (ATE):

These are Equipments that automatically test and analyze functional parameters to calculate performance of the tested electronic devices.

Base Copper:

The thin copper foil area of a copper-clad laminate for Printed Circuit Boards. Copper foil can be present on one or both sides of the board, and on inner layers.

Base Material:

A conductive pattern can be built on a dielectric or insulated metal sheet. This metal sheet is termed as Base material. Base material can be rigid or flexible or both.

Blank Circuit Board:

Blank Circuit Boards are made by bonding a thin layer of 1 ounce of copper over one or both sides of the entire substrate. To etch a circuit design into the material, unwanted copper can be removed using a CNC machine, leaving only traces. Free software like Eagle CAD, a vector based 2D program will work for designing circuit patterns to upload to the machine for milling. The circuit can also be drawn on the boards using a chemical mask pen and then chemically etched to remove the unwanted material.

Board Thickness:

The overall thickness of the base material and all conductive material deposited on it is termed as Board thickness.

Bread Board Circuits:

One of the simplest to construct circuits is the breadboard circuit. The breadboard circuit makes alteration of a design very easy, which means it is very forbearing when it comes to make mistakes while designing the circuit. It also does not require soldering, which makes it a good choice for children.

Chip-on-Board (COB):

A configuration in which a wafer of silicon (chip) is directly assembled to a PCB or substrate by solder or conductive adhesives

Clearances:

The distance from a power or a ground layer to a plated through hole is termed as Clearance or isolation.

Component Side:

The sides of the circuit board on which most of the components like capacitor, inductor, or integrated circuit (IC) are mounted are termed as Component side.

Continuous Outline:

The outline that describes the shape of the printed circuit board as well as used for creating the route program is known as continuous line. The outline is made from a single continuous line for the printed circuit board.

Controlled Impedance:

The matching of substrate material electrical characteristics with trace dimensions and locations to build specific electric impedance as seen by a signal on the trace

Coaxial cable is most used from antenna cable to a TV, with an inner conductor insulated from the outer cylindrical conductor (shield). The dimensions of the conductors and insulator, and the electrical characteristics of the insulator are carefully controlled in order to determine the shape, strength and interaction of the electrical fields, and in turn the electrical impedance of the cable.

Likewise many different trace configurations are used in the PCB industry to achieve controlled impedance.

Copper (Finished Copper) Weight:

This is a coated copper layer on the board surface. The value is obtained from the thickness of copper foil add with plated copper then subtract copper that is removed during surface preparation. Copper weight is measured in oz /sq foot.

1 oz = a minimum of 0.0012” thickness.

Cover Lay (Flexible Circuit):

The conductive pattern on the outer surfaces of a printed circuit board is covered completely or partially by the layer of insulating material.

CTI Comparative Tracking Index:

This term is used to measure the tracking characteristics of an insulating material. Tracking is an electrical breakdown on the surface of an insulating material .Tracking can be measured with 50 drops of 0.1% ammonium chloride solution drop on the material, and the voltage measured for a 3mm thickness is considered representative of the material performance.

A large voltage difference gradually creates a conductive leakage path across the surface of the material by forming a carbonized track. The CTI value is used for electrical safety assessment of electrical apparatus.

Cut Lines:

The router path can be programmed with the help of cutline and the outside edge of circuit board is represented by cutline. “. It is suggested to keep outer copper layer 0.010” and inner copper layer 0.020” from the cut line to avoid exposing copper at the board edge. The tolerance on route dimension is +/- 0.010

Date Code:

All products are marked to indicate their date of manufacture .ACI standard format is WWYY stands for weekweekyearyear.

Design Rule Checking:

Computer programs are used to implement continuity verification of all conductors routing according to specified design rules.

Drill Tool Description:

These are test files that describe the drill tool number, quantity, corresponding size and the holes need to be plated n non-plated.

Electrical Test:

Electrical test is performed to check the continuity and isolation of circuit boards. The standard testing parameters used are 100 Volts, Isolation Resistance of 10 M Ohms, Isolation Distance 0.050”, and Continuity Resistance of 50 Ohms.

A net list is produced from the customer given Gerber files and then electrically compared to the completed printed circuit board. The solder mask layer acts as the mask to conclude what can be tested. In general, endpoints of all of the nets are programmed for testing unless they are covered in solder mask.

Embedded Traces:

A trace that is enclosed by ground fill. Embedded traces have different manufacturing characteristics that do not behave as traces grouped in tight runs do. The etching process is slow for these traces.

ENIG (Electro less Nickel Immersion Gold):

A type of surface plating used for printed circuit boards is known as Electroless nickel immersion gold (ENIG). This type of surface plating consists of electroless nickel plating covered with a thin layer of immersion gold, which protects the nickel from oxidation.

ENIG has several advantages like excellent surface planarity, good oxidation resistance, and usability for untreated contact surfaces such as membrane switches and contact points.

Etching:

Etching is a process in which unwanted metal (copper) is removed with the help of strong acid to achieve desired circuit pattern.

Etching is used in the manufacturing of printed circuit boards and semiconductor devices and in the preparation of metallic specimens for microscopic observation.

Etch Factor:

It is the ratio between the depths of etches (copper thickness) and the amount of lateral etch (undercut).

Fabrication Drawing:

Fabrication drawing elaborates the size and tolerances of holes to be drilled, location of the holes, dimensions of the board edges, and notes on the materials and methods to be used. It helps to construct printed circuit board correctly.

Flexible Circuit Board:

A Flexible Circuit board utilizes flexible base material with or without flexible overlay. The benefit of a flexible PCB is that it can save space and weight, which means overall production costs are reduced and it’s easier to assemble the final product.

Gerber Files:

A single conductor or mask layer image is defined by a Gerber File. The function of file in printed circuit board is defined by file function attributes in a standard way.

A PCB design is described by a number of Gerber files and files in other formats. Typically, all these files are “zipped” into a single archive that is sent to the PCB fabrication shop.The standard file extension is .GBR

Gerber Viewer:

Gerber viewer is a software tool that helps you to upload Gerber files and have a 360 degree view of your PCB design with 3D Gerber viewer.

Gold Fingers:

These are the gold plated connectors from the edge of the PCB to other connectors so PCB should be mounted at 90 degrees. It is usually on top and bottom of the printed circuit board.

HASL (Hot Air Solder Level):

A type of finish used on printed circuit boardsis HASL (Hot air solder level). All exposed copper surfaces are covered by solder by dipping printed circuit board into a bath of molten solder .PCB is passed between hot air knives to remove excess solder. Excellent wetting during component soldering is main HASL advantage.

HDI – (High Density Interconnect):

HDI PCBs is the latest technology to increase the functionality of Printed circuit boards using the same or less amount of area. This advance PCB technology is accomplished by the miniaturization of components and semiconductor packages that supports advanced features in touch screen computing and 4G network communications.

HDI PCBs are characterized by attributes laser microvias, fine lines and high performance thin materials. This increased density enables more functions per unit area.

Heat Sink:

Heat Sink is a mechanical device with high thermal conductivity and low specific heat material .It cools a device (i.e transistor, LED) by dissipating heat into the surrounding medium.

Heat sinks are used with power transistors, lasers, PCBS and light emitting diodes (LEDs), where the heat dissipation ability of the basic device is insufficient to moderate its temperature. In computers, heat sinks are used to cool central processing units or graphics processors.

Heat sink Plane :

Heat is dissipated from printed circuit board by a continuous metal sheet from heat generating components.

Imaging:

Electronic data is transferred to the photo-plotter by the process of Imaging. This process uses light to transfer a negative image circuitry pattern onto the panel or film.

Internal Power and Ground Layers:

Solid copper planes that are connected to ground or power in multilayer printed circuit board.

Lamination:

The method of manufacturing a product by bonding two or more layers together is termed as lamination. Lamination is performed usually with different materials under heat and pressure to form a single structure. A laminate has improved strength, stability, sound insulation, appearance or other properties from the use of different materials.

Land:

Land is also called pad. Land is the conductive area of printed circuit board for the mounting or attachment of components such as a resister, capacitor, DIP or connector, etc.

Layers:

Different sides of PCB are identified by layers. Each layer is generally connected by plated through holes. Depending on the design, the layer will contain not only copper traces, but also information such as Company name, logo etc

Layer Sequence:

Layer stacks are build with the help of Layer sequence and CAD easily identifies the type of layer.

Led Circuit Board:

LED circuit boards (LED PCB) are specially designed for LED strip lighting. LED circuit boards can carry up to 72 LEDs.All our LED products are ideal for use with solar power due to very low energy consumption

Lot Code:

A manufacture’s lot code is marked on PCB for future tracking purpose on customers demand. A drawing mentions the location of Lot code on PCB.

LPISM (Liquid Photo-image able Solder Mask):

Liquid Photo-image able Solder Mask is one of the types of solder mask.

Solder mask is a thin -like layer of polymer that is usually applied to the copper traces of a printed circuit board (PCB) for protection against oxidation and to prevent solder bridges from forming between closely spaced solder pads.   LPSM can be silkscreened or sprayed on the PCB, exposed to the pattern and developed to provide openings in the pattern for parts to be soldered to the copper pads.

Micro sectioning:

Mirosection is an essential tool in the quality control and evaluation of PCB manufacturing. It is very important tool for finding hidden substrate defects and for process control. Microsections are tiny specimen of a material, or materials that is to be used in metallographic examination. This usually consists of cutting out a cross-section followed by encapsulation, polishing, etching, and staining.

Minimum traces and Spaces:

Traces are the “Wires” of the Printed Circuit Board (also known as tracks).The distance between traces, the distance between pads or the distance between a pad and trace is termed as spaces.Trace width and the space between traces are used to define the complexity of printed circuit board design.

Multilayer PCB:

The multilayer printed circuit board consists of two or more layers pcbs which are stacked together with internal and external interconnections. The multilayer pcb is mainly used in professional electronic equipment, such computers and military equipment, especially in the case of the overload of weight and volume.

Non-Plated Holes:

Non-plated holes do not contain any copper plating but these holes are drilled through

a printed circuit board. They are used to mount components to a printed circuit board.

Non-Plated holes should maintain a minimum clearance of 0.010” from any conductive surface.

Non-Supported Holes:

These are holes in printed circuit board that don’t contain any copper plating.

Number of Holes:

This is the total number of holes to be drilled in the board.

PAD:

PAD is the conductive area of printed circuit board for the mounting or attachment of components such as a resister, capacitor, DIP or connector, etc.

PART Number:

Part number defines the name or number associated with your printed circuit board design.

Plated Through Holes:

Plated through holes (PTH) are holes on your PCB that have copper plating that makes an electrical connection between conductive patterns on internal layers, external layers, or both, of a printed board.

Printed Circuit Board:

A PCB (Printed Circuit Board) is a thin board made of fiberglass, composite epoxy, or other laminate material. Conductive pathways are etched or “printed” onto board, connecting different components on the PCB, such as transistors, resistors, and integrated circuits.

Readme File:

Readme file maintains all the information related to manufacture your order. It contains information like company name, phone numbers, email address of engineers or designers etc

Rigid-Flex:

Rigid flex printed circuit boards are boards using a combination of flexible and rigid board technologies. They are consists of multiple layers of flexible circuit substrates attached to one or more rigid boards externally and/or internally, depending upon the design of the application.

RoHS (Restriction of Hazardous Substances):

RoHS stands for Restriction of Hazardous Substances. RoHS, also known as Directive 2002/95/EC, aims to restrict certain dangerous substances commonly used in electronic and electronic equipment.

Silk Screen:

The process of marking colors on the PCB board to identify components for later assembly and troubleshooting processes. Colors can be marked on any side of the PCB depending on the board design and application. White is the standard silk screen color.

Single-Sided Boards:

A printed circuit board that contains conductive components on one side of the board is termed as single sided board.

Smallest Hole:

The smallest drilled hole in the design is termed as smallest hole.

Solder Mask:

Solder mask is a protective thin layer applied on the copper traces of printed circuit board for protection against oxidation and to prevent forming solder bridges.

Solder Mask Color:

There are different colors available for solder mask but most common is green.

Solder Bridge:

An unwanted electrical connection between two conductors on printed circuit board is termed as Solder Bridge. Solder bridge prevents with the help of solder mask.

Strip Board Circuits:

The circuit board that is ideal for smaller, more compact electronic projects, rather than larger ones are Strip board Circuits. Strip board Circuits are made of plastic and have holes running through the entire length of the circuit board. One side of the board consists of copper track strips. The board is permanent, as it requires soldering to work properly. Since the board has lots of holes, it can be easy to solder wrongly or to place a component in the wrong area.

Tab Routing:

An array of printed circuit board is formed with the help of method termed as tab routing for automated assembly.

UL:

UL stands for underwriters Laboratories. UL provides safety-related certification, validation, testing, inspection and auditing for electrical devices.