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38 Cards in this Set
- Front
- Back
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Schematic |
A document used by ircuit designer to show the electrical connection between components that will be made into printed circuit board (PCB). |
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Components |
Know how to idenitify the following parts on schematic: Resistors, Capacitors, Inductors, Transistors, Conectors and IC's. |
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Nets |
A net is the connection between two or more pins of components on a schematic. |
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Nodes |
A node is junction where a net splits into three or more directions. Nodes are designated on a schematic by filled . |
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Reference Designators |
Reference designators are alpha numeric strings that uniquely identify each component on a board regardless of component type or value. For instance, the reference designation for schematic with two identical is package and value 10K Ohm resistors would have unique strings such as R1 and R2. On a PCB the reference designation would typically (but not always) be printed on the silk screen layer of the board as an indicator to assembler as to where to install what component. |
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Title Block |
Small graphical vlock on schematic page that indicate the circuit name, designer, part number, revision and other information that is pertinent to company or individual designing the board. |
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BOMS |
BOMS (Bill of Materials) --> use as tool to order and assemble parts. BOMS are used to map reference designator to manufactures and distributors parts number. |
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PCB |
PCB(Printed Circuit Board) |
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Component Footprint |
Component footprint is the graphical element that will become the copper pattern on the surface of the PCB that will be used for mounting a component to the boar. |
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Through Hole |
Through-Hole often spelled (thru-hole) footprints are primarily distinguished by graphical element that represent mounting pad that will exist on all copper layers of the board with a drill hole centered in the pad that plated through. |
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Donuts/Annular Ring |
The donut or annular ring is the graphical element and the width of which is specified from the drill outer diameter to ring outer diameter. |
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SMT |
SMT (surface mount) --> Surface mount (SMT) footprints are primarily distinguished by graphical elements that represent mounting pad that will exist on only single copper layer(either top or bottom) of the oard. |
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Trace |
The net of schematic become copper traces (or tracks) that lay on the surface of the PCB. |
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Silk Screen |
Non0conductive ink printed on the top side (optionally bottom side) of a PCB that is used to convey human readable information to the assembler or user of the board. Silkscreen text can indicate component designators, x-y dimensions of component, switch setting requirements, test points, and other features helpful in assembling, testing, and servicing the circuit board. |
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Solder Mask |
non Conductive material printed over copper layers on the top and bottom of board that prevents oxidation of surface metal of the board, and prevents solder from bridging between conductors, therey preventing short circuits. it's the green stuff. |
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Top side |
top or component side of at PCB is the copper layer on the side of the board that the majority of the components are placed. |
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bottom side |
Bottom or solder side of the PCB is copper layer on the side of the board that the majority of the components are placed. |
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Inner Layers |
Inner layers provide addition current paths for complicated circuits or ones requiring planes for RF considerations. |
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Substrate Material |
"Substrate material" is the base (sub) material which the copper traces of the PCB are laminated too. The most common substrate material is fiberglass material of type FR4. FR4 is a standard by which the material is able to resist fire, hence the FR (Fire Resistance). |
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Vias |
Very small plated through holes to allow a signal to get from one copper layer to another. |
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Drill Sizes/ Hole Size |
The diameter of a hole that is to be drilled on a PCB. |
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Solder |
Solder is fusible metal alloy with a melting point or melting range of 90 to 450 degree Celsius (190 to 840 F) used in a process called soldering where it is melted to join metallic surfaces. Alloys that melt between 180 and 190 C (360 and 370 F ) are the most commonly used. By definition, using alloys with melting point above 450 C (840 F) is called Brazing. Solder can contain lead and/ or flux but in many application solder is now lead free. |
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Flux |
flux is a chemical cleaning agent that facilitates soldering, brazing, and welding by removing oxidation from the metals to be joined. Common flux: Ammonium Chloride or Rosin for soldering tin; hydrochloric acid and zinc chloridefor soldering galavanized iron ( and other Zinc surfaces) ; and borax for brazing or braze-welding ferrous metals. |
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Solder Wick |
A solder wick (also desoldering wick or desoldering braid) is a tool for removing solder from any solder joint. usually, it is a roll of fine, braided 18 to 42 AWG wire, typically oxygen free copper, which has been trated with a rosin solder flux. |
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Soldering Iron |
A soldering iron is a hand tool most commonly used in soldering. it supplies heat to melt the solder so that it can flow into the joint between two workplaces. "A soldering iron is composed of a heated metal tip and insulated handle. Heating is often achieved electrically, by passing an electrical curreent (supplied through an electrical cord or battery cables) through the resistive material of heating element. Another heating method includes combustion of suitable gas, which can either be delivered through a tank mounted on the iron (flameless ), or through an external flame. |
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Conformal Coating |
A coating applied to electronic circuitry to act as protection against moisture, dust, chemicals, and temperature extremes that, if uncoated ( non-protected) , could result in damage or failure of the electronics to function. |
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Potting |
A process of filling a complete electronic assembly with a solid or gelatinous compound for resistance to shock and vibration, and for exclusion of moisture and corrosive agents. |
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Wave Soldering (for thrus hold components) |
Machine that flows solder on to the bottom layer of a PCB in ontinuous process that allows for soldering hundreds of through-hole joints in seconds. |
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Pick-N-Plae Machines |
Machine used to place components |
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Stencil |
Laser cut metal stencil used for screening solder paste on to surface mount PCB. |
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Re-flow oven |
Oven used to precisely control air temperature in a raping fashion for soldering surface mount parts. |
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Manufacture |
Manufacture is the company that makes a part, some times abbreviated OEM for Original Equipment Manufacture. |
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Manufacture Part Number |
Along withthe manufacture, the can be used to identify a unique parts to be installed on a PCB. The manufacture mst be taken in to consideration since two manufactures may make different parts with the same part number. |
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Distributor |
Distributor is company that sells parts from many different manufactures making it easy to order many components from a single source. |
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Distributor Part Numbers |
A distributor part number is a string of numbers that identify a manufacture and manufactures part number that can be ordered from the supplying destructor. |
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Internal/Customer Part Numbers |
A distributor part number is a string of numbers that identify a manufacture and manufactures part number. |
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Gerber File |
Gerber format is a file formate used by printed circuit board (PCB) industry software to descrive the images of printed circuit board (copper layer, solder mask, legend , etc.) as well as the drilling and milling data. Gerber formate is the industry standard for printed circuit board image transfer. |
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Turnkey |
A type of product that is constructed by a developer and sold or turned over to buyer in a ready to use condition , ready for immediate use. |
