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PCB Circuit Design and Manufacturing Terminology

Warm hints: The word in this article is about 8332 and  reading time is about 40 minutes.   
Guidance:  Designing a circuit as an electronic engineer is a must-have hard work, but the principle design is perfect, if the board design is unreasonable, performance will Greatly discounted, even when it is serious, it can't work normally. This article has compiled 104 collections of terminology design for the PCB line, hoping to improve your work efficiency!

Annular Ring

refers to the through hole through holeThe outer wall is flat on the copper ring on the board. On the inner layer, the hole ring is often connected to the outside by a cross bridge, and is more often used as the end point or over station of the line. In addition to the over-station of the line on the outer layer, it can also be used as a pad for soldering the parts. There are also Pad (with circle), Land (independence point), etc., which are synonymous with this word.

Artwork Films

Artwork Films In the circuit board industry, this word often refers to black and white negatives. As for the brown “Diazo Film”, it is also named by Phototool. The negatives used in PCB can be divided into “Original Film” Master Artwork and the “Working Film” Working Artwork, etc..

Basic Grid

The grid refers to the timing of the board, and the vertical and horizontal grids of the conductor layout are located. The early grid spacing is 100 mil, which is currently due to the prevalence of fine lines. The basic grid spacing has been reduced to 50 mils.

Blind Via Hole blind

Blind Via Hole blind vias refer to complex multi-layer boards, some of which are due to only Some layers of interconnection are required, so they are not completely drilled through. If one of the holes is connected to the hole ring of the outer layer, this special hole like a cup-shaped dead end,Call it “Blind Hole.”

Circuit Block Diagram 

The circuit block diagram will assemble the board and the various components required, on the design Square or rectangular empty frames are framed, and various electrical symbols are used to communicate the relationship of each frame one by one to form a systematic architectural diagram.

Bomb Sight bulletin

The Bomb Sight bulletin originally referred to the bombardment of the bomber. PCB In the production of the film, the target for alignment of the upper and lower layers is also set in each corner for the purpose of alignment. The more precise official name should be called Photographers’ Target.

Break-away panel

The breakable board refers to many smaller boards, for plug-ins and placements on downstream assembly lines, For the convenience of welding, etc.In the PCB process, the combination is combined on a large board for various processing. At the time of completion, the local cut shape (Routing) is broken between the individual small plates, but several “slices” of sufficient strength are retained (Tie Bar or Break-away Tab), and drill several small holes between the splicing and the edge of the board; or cut the V-shaped notches up and down to facilitate the assembly process, and also break the boards apart. This small board joint assembly method will become more and more in the future, and the IC card is an example.

Buried Via Hole

Buried Via Hole refers to the local via hole of the multi-layer board. When it is buried in the inner layer of the multi-layer board, it becomes an “internal through hole”. “, and is not connected to the outer layer,” is called a buried hole or a buried hole.

Bus Bar

Bus Bar refers to the cathode or anode rod itself on the plating tank, or its connected cable. . In the “process” circuit board, the outer edge of the golden finger is close to the edge of the board.The original connecting wire (which must be covered during the gold plating operation), and a small narrow piece (all need to reduce the size of the gold, so as to minimize the area) is connected with each finger, this conductive connection is also Called Bus Bar. The small piece that connects the individual fingers to the Bus Bar is called the Shooting Bar. When the board finishes cutting, both will be cut off.

CAD computer-aided design

Computer Aided Design, is to use special software and hard Body, the board is digitally laid out (Layout), and the digital data is converted into original film by optical plotter. This kind of CAD is more accurate and convenient than the manual method for the pre-production engineering of the circuit board.

Center-to-Center Spacing

Center spacing refers to the center-to-center Nominal Distance of any two conductors on the board.If the conductors are arranged in series, and the width and spacing are the same (such as the arrangement of the gold fingers), the “center-to-center spacing” is also called the pitch (Pitch).


Clearance, and empty ring refer to the inner layers of the multi-layer board. If you do not want the conductor surface to communicate with the hole wall of the through hole When the copper foil around the through hole is etched away to form an empty ring, it is called an “empty ring”. The distance between the green paint printed on the outer panel and the rings is also called Clearance. However, due to the increasing density of the board surface, the original space of this green paint has been pushed to almost nowhere.

Component Hole

The hole of the part is the through hole of the part on the board. The hole diameter of this hole is about 40 mil on average. Nowadays, after the prevailing of SMT, the large caliber jack has been gradually reduced, and only a few of the connectors gold pinholes need to be soldered,most of the remaining SMD parts have bee modified to be surface mounted.

Component Side

Component surface in the era of full board through hole insertion, the part must be installed on the front of the board, it is also known as The front side is the “component surface”. The opposite side of the board is also called the “Soldering Side” because it only passes through the solder wave. At present, SMT’s board has adhesive parts on both sides, so there is no such thing as “component surface” or “solder surface”, which can only be called front or back. The name of the manufacturer of the electronic machine is usually printed on the front side, and the UL code and date of manufacture of the board manufacturer can be added to the reverse side of the board.

Conductor Spacing

Conductor spacing refers to a conductor on a board surface, from its edge to the edge of another nearest conductor, covering the insulating substrate surface The span, which is called the conductor spacing, or the so-called spacing. also,Conductor is a generic term for various forms of metal conductors on a board.

Contact Area

Contact Resistance on the board is specifically the contact point between the gold finger and the connector, when The current is the resistance that is presented when passing through. In order to reduce the formation of oxides on the metal surface, the positive gold finger portion and the negative clip of the connector are all plated with metal to prevent the occurrence of “loading resistance”. Plugs of other electrical products are squeezed into the socket, or there is contact resistance between the guide pin and its socket.

Corner Mark

The board marks the board negatives, often leaving special marks at the four corners as the actual boundaries of the board. If the inner edges of these marks are wired, it is the boundary of the contour of the finished board contour (Contour).

Counterboring deepening reaming

The countersunk circuit board can be fastened to the machine with a screw. The matching non-conducting hole (NPTH) must have a “reaming” that can accommodate the nut, so that the whole screw Can sink into the surface of the board to reduce the obstacles caused by the appearance.


Cross-section area of some large-area conductor area, in order to get better adhesion between the board surface and green paint In the first place, the copper surface is often turned away, leaving a number of crisscross crosses, such as the structure of a tennis racket, which will dissolve the large area of copper foil, the floating crisis due to thermal expansion. The cross pattern obtained by etching is called Crosshatch, and this improvement is called Crosshatching.

Countersinking Cone-type reaming

Countersinking Cone-type reaming, the horn hole is another kind of screw hole for locking, which is mostly used in wood furniture, and there is less precision electronics industry. in.Crossection Area

The cross-sectional area of the circuit board on the cross-sectional area will directly affect its current carrying capacity, so it should be listed first when designing. Often the part of the copper surface is turned away, leaving a number of crisscross crosses, such as the structure of the tennis racket, which will dissolve the large area of copper foil, the floating crisis due to thermal expansion. The cross pattern obtained by etching is called Crosshatch, and this improvement is called Crosshatching.

Current-Carrying Capability

The current-carrying capacity refers to the wire on the board that can continuously pass the maximum current intensity (amperes) under specified conditions. It does not cause degradation of the board’s electrical and mechanical properties. The amperage of this maximum current is the “current carrying capacity” of the line.

Datum Reference benchmark

Datum Reference benchmark reference in the PCB manufacturing and inspection process, in order to be able to correctly position the film graphic on the board surface, select a point, line, or hole surface as a reference for its graphics, Called Datum Point, Datum Line, or Datum Level (Plane), also known as Datum Hole.

Dummy Land fake pads

Dummy Land fake pads are assembled for the sake of The height of the existing parts, the surface of the parts under the belly of some parts needs to be padded, so that the dispensing can have a better adhesion. Generally, the etching technology of the board can be used, and the left side of the part is deliberately left unpowered. The “fake copper pad” used for padding is called Dummy Land. However, due to poor design on the board surface, there will be a large area of copper-free substrate surface with a small number of through holes or lines. These independent conductors concentrate excessive current during copper plating, and various defects can be added, and some non-functional dummy pads or false wires can be added to share some current during plating.Let the current density of a few independent conductors be not too high. These copper faces are also called Dummy Conductors.

Edge Spacing

Edge Spacing refers to the open space between the edge of the board and the “nearest conductor line”. The purpose of this open space is to avoid The conductor is too close to the edge of the board, and may be short-circuited with other parts of the machine. The safety certification of UL in the United States is particularly particular about this project. Generally, the shortcomings such as white edge layering of the board cannot penetrate into the half of the width of the “edge”.

Edge-Board contact plate gold finger

Edge-Board contact plate gold finger is the export of the whole board to the external contact, usually more than two sides of the board side symmetrical, can be plugged In the matching board edge connector.

Fan Out Wiring/Fan in Wiring Fan-out wiring/fan-in wiring

Fan Out Wiring/Fan in Wiring Fan-out wiring/fan-in wiring refers to conductors such as lines and through-holes drawn from the pads around QFP.The task of interconnecting the soldered part with the board. Since the rectangular pads are arranged very tightly, the external contact must be routed in a fan-shaped manner by means of an open space outside the rectangular pad square or the rectangular pad square ring, which is called “fan-out” or “fan-in”. Lighter, thinner and shorter dense PCBs, where more pads can be placed on the outer layer to take in more parts, and the wiring required for interconnection is hidden to the next layer. The connection between the pads and the leads between the different layers is directly connected by the blind holes in the pads, and there is no need to fan-out the fan-in wiring. At present, many high-function small-sized wireless telephones have adopted this new type of lamination. With the wiring method.

Fiducial Mark optical target

Fiducial Mark optical target, the reference signal on the board for downstream assembly, convenient for visual aid system operation, often A large IC is placed on the open space on the outer edge of each pad at the board assembly position, and a triangular “optical target” is added to the upper right and lower left to assist the placement machine in optical positioning. The PCB process often adds more than two reference marks for the alignment of the film and the plate surface.

Fillet internal fillet

Fillet internal fillet refers to two planes or two straight lines, in the case of arcs filled at their vertical intersections. In the circuit board, it is often referred to as the solder joint of the component lead, or the inner circle of the intersection of the T-shaped or L-shaped circuit of the board surface, etc., to enhance the mechanical strength and current circulation convenience.

Film Negative

Film Negative refers to the film with existing line graphics. Usually available in thicknesses of 7 mils and 4 mils, the photosensitive film is black and white silver halide, and brown or other color azo compounds, also known as Artwork.

Fine Line

Thin line according to the current technical level, four lines between the holes or the average line width of 5 ~ 6mil or less, called the thin line.

Fine Pitch

Fine Pitch, closely spaced, dense line spacing,A pad with a Lead Pitch equal to or less than 0.635 mm (25 mils) is called a close distance.

Finger finger

Finger finger (continuous alignment of the board edge) on the board to enable the function of the entire assembly board to be externally contacted, the board edge can be used The “positive” gold-plated continuous contacts are inserted into the “female” continuous receiver of another system to enable the interconnection between the systems. The official name of Finger is “Edge-Board Contact”.

Finishing Finishing, Final Repair

refers to the appearance of various finished products The final finishing or finishing work on the product makes the product more beautiful, protective, and textured. Metal Finishing refers to a metal part or product, which is specially treated to enhance the corrosion protection function and the treatment layer.Such as various plating layers, anodized coatings, coatings of organic or inorganic materials, etc., are all of them.

Form-to-List wiring instructions list is a list of written instructions indicating various wiring systems

Gerber Date

Gerber File Geber file is a series of complete software developed by American company Gerber for circuit board circuit graphics and holes. file. The designer or the company that buys the board can convert all the graphic data of a certain item number into Gerber File (the official scientific name is “RS 274 format”), which is directly transmitted to the PCB manufacturer via Modem, and then from its own CAM. The medium output, combined with the operation of the laser plotter (Laser Plotter), results in drilling, testing, line film, green lacquer film, and even downstream assembly and other specific work materials, so that PCB manufacturers can immediately engage in proofing or production. Save a lot of communication and waiting time.This kind of circuit board “pre-production engineering” computer software of various materials, currently in the global industry are based on Gerber File. In addition, there is another software development of IPC-D-350D, but it has not been widely used.

Grid standard

Grid refers to the basic latitude and longitude squares when the board is wired. The early long and wide grids are each 100 mil, which is ” The pitch of the integrated circuit (IC) pin is referenced, and current dense assembly has caused the Grid to approach 50 mils or even 25 mils. Located at the intersection of the grid is called On Grid.

Ground Plane

Clearance Grounding Empty Loop “Integrated Circuit” Whether it is a traditional IC or VLSI, its grounding or voltage foot, and its ground plane ( After the GND) or the voltage layer of the voltage layer (Vcc) is connected, it is interconnected with the large copper surface by a “slot bridge” or “cross bridge”.As for the through hole that passes through the layer and does not completely connect the copper surface, it is necessary to cancel any bridge and be isolated from the outside. In order to avoid deformation due to heat, a Clearance Ring required for expansion must be left between the through hole and the large copper surface. Therefore, it can be judged whether it is GND or Vcc from the level of the known pin. General through hole production If the stations are poorly managed, a “pink circle” will occur, but the pink circle should only appear on the Annular Ring within the Clearance Ring, and should not cross the empty ring. If it penetrates into the earth, it will be too much.

Ground plane (or Earth Plane)

The ground plane is a kind of board that belongs to the inner layer of the multi-layer board. A grounding layer with a large copper surface is required to be used for grounding, Shielding, and heatsinking of many parts common circuits.Take the traditional TTL logic double-row IC as an example. When viewing from the front (back), the mark on one end faces up, and the left side is the first foot (usually the body next to the first foot will also be marked A small depression or white point is used as the identification), and the last leg of the row is “grounding foot”. Then press the counterclockwise number to the last leg of the other row, which is the pin of the Power Plane.

Hole Density

The hole number density refers to the number of holes drilled in the unit area.

Indexing Hole Reference hole

reference hole refers to the board in the manufacturing process at the corner of the board or the edge of the board to drill some tool holes to be used as other images Transfer, drill, or cut shape, and the basic reference point for the press process, called Indexing Hole. Others have similar terms like Indexing Edge, Slot, Notch, and so on.

Inspection Overlay

Inspection Overlay is a translucent film negative or positive (such as Diazo’s brown, green or blue). It can be used as a tool for visual inspection on the board surface. This method can be used for the visual inspection of the “First Article”.

Key key slot

the former on the circuit board refers to the slotted notch at a certain position in the gold finger area, the purpose is to have another negative The connector is matched, and a foolproof design that is not reversed when plugged in is called Keying Slot. The latter refers to a sealed touch button with a spring contact, which can be used as a quick turn-on and jump-off of telecommunications.

Land hole ring

Land hole ring, surface (square) pad Before the SMT was introduced before, the traditional parts were welded with their foot sockets Hole ring on the deck surface,In addition to being a relay station for conductive interconnections, a strong tapered solder joint can be formed with the leads. Later, the surface was prevailed, and the square-shaped solder pads that were changed were also called Land. This word can be translated as “weld ring” or “matching ring” or “pad”, but if translated into “Landao” or “eyes” it would be too far off the mark.

Landless Hole Non-circular through-hole

Landless Hole Non-circular through-hole refers to some densely packed boards, because the board surface needs to be arranged with many lines and square pads for the attached parts. There are very few open spaces left. Sometimes the pair is no longer used for outer wiring or soldering. If it is only used as a Via Hole for interlayer conduction, the hole ring can be removed and more space can be removed for wiring. Such a through hole having only an inner hole ring and no outer hole ring is specifically called a Landless Hole.

Laser Photogenerator (LPG)

Laser Photogenerator (LPG),The Laser Photoplotter laser exposure machine directly uses the laser’s single beam of parallel light in conjunction with computer control to expose the original Artwork of the PCB to replace the original original large patch (Tape-up). ), and the original negative film that has been reduced. The transportation of such original film is very troublesome. Once the temperature and humidity change, the size of the finished board will be different, and the quality of the precision board will be greatly affected. Nowadays, the disk data can be obtained directly from the customer, and the laser can be used to obtain excellent negative film, which is very helpful for the production and quality of the circuit board.

Lay Out wiring

Lay Out wiring, layout refers to the layout of the board in the design, the arrangement of each part in each level, as well as the direction of the wire, the position of the through hole, etc. The layout is called Lay Out.

Layer to Layer

Layer to Layer Spacing The distance between layers is the distance between the two copper foil conductor layers of the multilayer board.Or refers to the thickness of the insulating medium. Generally, in order to eliminate the noise generated by adjacent circuits on the board surface, the thinner the medium in the layer spacing is, the better the noise generated can be introduced into the ground layer. However, how to avoid the leakage caused by the medium being too thin and to maintain the necessary flatness is another problem that is difficult to overcome.

Master Drawing

Master Drawing The main picture refers to the main reference of various specifications on the board manufacturing, and also records the dimensions and special requirements of the board, which is commonly known as ” The blueprint is an important basis for quality inspection. Everything needs to be “pictured”. Unless the main picture can be changed in the further information (or telegram or fax, etc.) signed by the licensor, the authority of the main picture is unavoidable. Although its priority is lower than orders and special materials, it is more important than the various written “Specs” and practices.

Metal Halide Lamp

Metal halide lamp iodine is one of halogens.Iodine is easily “sublimed” into a gas by solids at high temperatures. In an incandescent light bulb having a tungsten filament illuminator, if iodine is charged therein, iodine gas is formed at a high temperature. This iodine gas can capture the vaporized tungsten atoms and react chemically, which will cause the tungsten atoms to fall back into the tungsten wire again, which will greatly reduce the consumption of the tungsten wire and increase the life of the bulb. It also enhances its current efficiency and enhances brightness. It is generally used for the light source required for the headlights, photography, film making and photo-sensing of automobiles. This iodine incandescent lamp is also a source of discontinuous spectrum. Its energy is concentrated in the spectral band of 410-430 nm in the ultraviolet region. Like the mercury gas lamp, it cannot be switched at will. However, when you are not working, you can use lower energy to maintain a temporary state of rest, so that you can get an instant immediate response when you use it again.

Mil is a tiny unit of length

Mil is a tiny unit of length, which is one thousandth of a mile [0.001 in]. It is commonly used in the circuit board industry to express “thickness.” This word was originally translated in the mechanical industry as “English silk” or simply “silk”, and it has been for a long time.The most basic jargon. However, some PCB practitioners of the early American company “Ampere Electronics” did not delve into it in the unknown, and conflated it with the “strip” (ie 10 micrometers) of another metric micro-length unit. It has been passed down to the present day, and most of the industry and even the downstream assembly industry have been entrenched in the past 20 years. Even if you want to correct it, it is not easy. The most puzzling thing is that even the thickness of the gold-plated gold-plated layer (m-in) is not the same as the “strip”, which is inexplicable. On the contrary, the mainland PCB industry is still used correctly. In addition, if the three letters are all capitalized into MIL, it is a shorthand for “Military” Military, often used in US military regulations (such as MIL-P-13949H, or MIL-P-55110D) and US military standards (such as MIL-STD-202, etc.) ) in written or spoken language.

Minimum Electrical Spacing

Minimum Electrical Spacing The lower limit of electrical spacing, the narrowest electrical spacing means between two conductors, at a specified voltage,To avoid the collapse of the medium during the break, or to prevent Corona, the minimum distance it should have is the “lower limit”.

Mounting Hole

Mounting hole is a non-conductive independent large hole on the circuit board, which is used to lock the assembly board on the body structure. . This type of hole for mechanical use is called a “mounting hole.” This term also refers to the mechanical hole used to lock a heavier part with a screw on the board.

Mounting Hole assembly hole

Mounting Hole assembly hole, the machine hole is the tool hole that is fixed to the machine base or the outer casing by screws or other metal fasteners. , is a large hole with a diameter of about 160mil. In the early stage, the PTH of the large hole ring and the copper wall of the hole was taken in the early stage, and then the screw hole was prevented from being affected by the tin in the wave soldering, and the new design specially changed the large hole into the “non-plated through hole”. (make a secondary hole before covering or copper plating before PTH)In addition, several small through holes are made in the surrounding ring width to strengthen the fixing strength of the hole ring on the board surface. Due to the cumbersome NPTH, the SMT board has recently changed the large hole back to the PTH. The two face rings are mostly different. The large ring of the welding surface is usually canceled and changed into several independent small rings, or changed to a horseshoe shape. The complete large ring, or the expanded area is shaped into a large copper surface, and used as a grounding.

Negative film

Negative film, the narrowing of the outer edge of the first side of the drill tip refers to various negative films (such as black and white film, brown film and glass film, etc.) The pattern of the conductor lines is presented as a transparent area, while the portion of the substrate without conductors appears as a dark area (ie, a black or brown portion of the film) to prevent transmission of ultraviolet light. This type of negative film is called a negative film.

Non-Circular Land

Non-circular hole ring pads The parts on the early circuit board are mainly through-hole inserts, after filling the holes Complete the function of interconnection (Interconnection). Some larger or heavier parts,In order to make the welding strength on the board surface better, the ring-shaped welding pad outside the hole is deliberately enlarged to strengthen the adhesion of the welding ring and form a large tapered solder joint. This large pad is especially common on single panels.

Pad Master round

Pad Master round pad film is a kind of original film supplied by early customers, referring to the black and white “positive film” with only “hole”. Each of the black circle pads has a small white space at the center, which is used as a “programming machine” to find the exact hole position. After the Pad Master finishes the hole program, the white space at the center of each pad is manually blackened and turned into a negative film, which becomes a green lacquer film. Nowadays, the designer has made all the required “components and scales” on the board into Gerber File’s magnetic sheets, and directly input them into the CAM and laser plotter to obtain the desired negatives, which not only saves manpower but also saves manpower. The quality has also increased significantly. The drawing is the corner of the new Pad Master film, which is the hole position of the sockets of two large ICs.

Pad solder pad

Pad solder pad, round pad This word in the original meaning of the board, refers to the welding base of the part pin on the board. Early through hole insertion era, indicating the hole ring on the outer board surface. 1985 In the SMT era after the year, this word also refers to the square solder pad on the board surface. However, this word is often extended to other related aspects, such as the dots or small circles on the inner panel surface that have not been drilled into the hole ring. Disk, the industry is also commonly called Pad; this word can be used with Land.

Panel process board

Panel process board refers to the board to be circulated in the process of each station A piece of Panel may contain several “Boards.” The size of these “process boards” may not be the same in each station. For example, the Panel surface of the press station may be very large, but to accommodate For each drilling axis operation of the drilling machine, it is only necessary to cut half or one-half of the Panel Size. When the area of the finished board is small, each panel can be divided into multiple boards. Usually, the Panel size is more Larger, the more economical the production.

Pattern board graphics

Pattern board graphics often refer to the conductor pattern or non-conductor graphics on the board surface, of course, the line pattern on the film or blueprint Called Pattern.

Photographic Film

The negative film refers to the original carrier of the circuit pattern on the circuit board, also known as the “Art Work”. Commonly used are Mylar-style films and hard sheets of glass plates. Its light-shielding film is made of black silver halide and brown azo compound (Diazo). The former can block almost all kinds of light, and the latter can only block ultraviolet light below 550nm. The visible light with a wavelength above 550 nm does not have a sensitizing effect on the dry film. Therefore, the working area can be illuminated by yellow light, which is much more convenient than the silver halide black and white film can only work under dark red light.


Plotter optical plotter is a mobile multi-strand single beam exposure method, instead of the traditional fixed point light source instant comprehensive exposure method. Under the digital and computer-aided design, PCB designers can The original hole ring, pad, wiring and size precision data are input into the computer under the Gerber File system and stored in a piece of magnetic disk. After the board manufacturer obtains the magnetic piece, the CAM and optical plotter can be used. It is operated to obtain a compact size film, which is free from deformation of the film during transportation. Since the common light source Photoplotter has many disadvantages, it has been eliminated. Now the industry has used laser light source as a plotter. Platform type (Flat Bed), inner cylinder (Inner drum), outer cylinder (Outer Drum), and separate regional models, etc., which have their own advantages and disadvantages, are the modern PCB factory must Tools available. It can also be used in other areas of photographic imaging, such as LCD, PCM, etc.

Phototool film

Phototool film usually refers to azo film (Diazo film), can work under yellow lighting, compared to black and white silver halide film that can only work under red light.


pin, pin refers to the tinned part of the board hole, or gold-plated pins, etc. Can be used as mechanical support and conductive mutual It is used as a medium for the assembly of early circuit board jacks. The Pitch is mostly specified as 100 mils in the early stage, which serves as the basis for the manufacture of circuit boards and various parts.

Pitch span

Pitch, pad distance, line pitch Pitch is purely the distance between the two “cell” centers of the board, PCB industry American expression commonly used mil pitch, that is, two welding The span between the centerlines of the pad is different. Pitch is different from Spacing, which usually refers to the “isolation plate” between two conductors, which is the area rather than the length.

Plotting plots

Plotting plots mechanically to map the coordinate data of X and Y in the plane coordinate system, depicting the operation process of the actual circuit diagram. It is called Plot or Plotting. At present, the production of negative film has abandoned the early tape-up (Tape up), and the use of “optical drawing” to complete the negative film, not only saves manpower, but also better quality.

Polarizing Slot

Grooving refers to the slotting of the gold finger area on the edge of the board. Generally, the position of the slot is deliberately biased to avoid symmetry due to left and right symmetry. Inverted, this is the direction slot that is added to ensure proper insertion, also known as Keying Slot.

Process Camera

Process camera is to make the film (Artwork) to enlarge, reduce, or get the film directly from the tape (Tape up) Dedicated camera.The composition has three large pieces standing on the movable track and parallel to each other, that is, the original patch or the mother frame at the right end in the figure, the lens, and the sub-frame to be imaged at the left end. This is the way to produce negative film in the early days. Now it has progressed to digital. The disk obtained from the customer can directly obtain the original film through the work of the computer software and the electro-plotter. It is no longer necessary to use the camera.

Production Master

Produces negative film 1:1 can be used directly on the raw film of the original inch film, as for the size and tolerance of each element, It must be listed on the main map (Master Drawing is also a blueprint).

Reference Dimension reference scale

Reference Dimension reference scale, reference size is only for reference data, because there is no tolerance, it can not be used as the basis for formal construction and quality inspection.

Reference Edge

Reference Edge refers to the edge of a conductor on the edge of the edge of the fingerboard, which can be used as a reference for the measurement of the full board size, sometimes referred to as a special identification mark.

Register Mark

Register Mark refers to the special mark set on the film or on the board surface, each frame or each corner, to check the pair between this layer or each layer In the quasi-case, the figure is the two commonly used alignment marks. The concentric circles can be arranged with different diameter rings at the edge or corner of each layer of the multi-layer board. Check the registration of the “sweeping out” (ie milling out) stereo concentric circles to determine the alignment between the layers.

various conductors

The actual position of the various conductors on the surface of the registration alignment board, and the original position of the original film or the original design, the degree of approximation between the two is called “Registration”. The mainland industry translates as “coincidence”. “Alignment” can refer to the degree of alignment of a conductor of a board with its backsheet;Or refers to the “Layer to Layer Registration” of the multi-layer board, which is an important quality of the PCB.

Revision revision

Revised version refers to the revision or version of the specification or product design, usually after the code is added with the capital letter of the uppercase A representation of the revision order.

Schematic Diagram circuit

Schematic diagram of the system line layout drawn by various symbols, electrical connections, part shapes, etc.

Secondary Side

This is the “Solder Side” of the original terminology of the board. Since the parts are welded on the first part of the socket (or Component Side; component side), the second side is only used for wave soldering contact, so it is called solder surface.In recent years, due to the rise of SMT surface mounting, there are many parts on both sides of the SMT, so it is not appropriate to continue to be called the solder surface, and the “second side” is more appropriate.


Slot, Slotting slot, slotted refers to the edge of the PCB or somewhere inside the board, in order to meet the needs of assembly, and must be “slotted” As a match, it is called a notch. In the side of the gold finger, also known as “Polarising Slot or Locating Slot”, it is deliberately opened to avoid the insertion of the gold finger female connector.

Solder Dam

Solder Dam, the embankment formed by the green paint thickness around the weld, can prevent the short circuit caused by the flow of molten tin in high temperature, usually Dry film solder masks are easier to form Solder Dam.

Solder Plug

Solder Plug, the tin column refers to the solder that is poured into the plated through hole during wave soldering.After cooling, it remains in the hole and becomes a part of the conductor, called “tin plug”. If there are already inserted part legs in the hole, the tin plug also has the function of “welding point”. As for the PTH that is currently not used for plugging, but only for interconnection purposes, it has been changed to a small hole with a diameter of 20 mil or less, which is called a Via Hole. Both ends of these holes are covered or filled with green paint to prevent the ingress of flux and molten tin. Of course, such a via hole will no longer have a Solder Plug.

Solder Side

Solder surface early circuit board assembly is completely through the through hole plug-in as the mainstream, the front side of the board (ie, the component surface) is often used to insert parts, The wiring is arranged in the direction of “board horizontal”. The reverse side of the board is used to match the tin wave of the pin through the wave soldering machine, so it is called the “welding surface”. This line is often routed in the “plate length” direction to obey the flow of the tin wave. Other names for this term include Secondary Side, Far Side, etc.


Spacing refers to the width of the insulating space between two parallel conductors. Usually, “pitch” and “line” are collectively referred to as “Line Pair.”


Span refers to the width covered between two special target points, or the distance between a target point and a reference point.

Spur film edge

Spur film edge highlights the transparent area or dark area of the film on the film, when the edge of the image is unclear, there are often prominent points, called Spur.

Step and Repeat successively repeat the board with small exposure area. For the convenience of production, the same pattern is often repeatedly arranged into a larger negative film in the film production stage. Using a special Step and Repect exposure machine, the same small pattern is partially exposed and then joined together to form a large negative film for mass production.

Supported Hole

Supported Hole refers to a normal plated through hole (PTH), that is, a hole with a metal hole wall. The previous “supportive” words are generally omitted. Original meaning is a through hole that is electrically conductive and provides for pin bonding purposes.

Tab contact

Tab contact, gold finger on the circuit board refers to the gold finger of the board edge series contact, is an informal statement.

Tape Up Master

Tape Up Master original hand patch film of the early board, not using CAD / CAM and laser plotter, but a variety of Dedicated black “stickers” (such as lines, round pads, gold fingers, etc., which are the most widely used products of Bishop), hand-applied to the original “slice” on square eye paper (Tape Up) Master), then use the camera to refine the first generation of the original film (Master Artwork).More than a decade ago, Japan had a lot of hand-chip work on circuit boards, that is, airlifting to Taiwan to seek OEM work. In recent years, due to the development and precision of computers, manual methods have been replaced.

Terminal Clearanceterminal empty ring

Terminal Clearanceterminal empty ring, the terminal allows the ring to ground (Ground) or voltage (Power) On the large copper surface, when the “plated through hole” is to pass through the inner layer and does not want to be connected, the copper surface at the hole position can be etched first, leaving a large circular open space. When the PTH copper hole wall is completed, a “empty ring” will appear around the periphery. In addition, when the green paint is printed on the outer surface of the outer layer, the “annular open space” should be given around the hole to be welded to prevent the green paint from contaminating the welding ring or even entering the hole. These two “empty rings” can also be called “Terminal Clearance.”


“Terminal” in the broad sense of the term “terminal” refers to various devices or parts that are electrically connected.The narrow usage on the board refers to the various annulus rings of the inner and outer layers. Synonyms include Pad, Land, Terminal Area, Terminal Pad, Solder Pad, etc.

Thermal Relief heat-dissipating hollow

Thermal Relief heat-dissipating hollow, no matter the large copper surface of the inner and outer plates, its continuous and complete area should not be too large, so as to avoid the plate at high temperature Medium (such as welding), due to the difference in expansion coefficient between the sheet and the copper sheet, causing the board to curl, float, or blister. Generally, a “tennis racket” type hollow can be used on the large copper surface to reduce thermal shock. This term is also known as Halfonning or Crosshatching. UL stipulates that in its certified “yellow card”, the diameter of the largest copper surface that needs to be placed on the board is a safety consideration.

Thermal Via

The vents are through holes on the bottom plate of large parts (such as CPUs or other driver ICs) with high power (such as 5W or more). These holes do not have conductive interconnection function and are only used for heat dissipation. . Sometimes it is connected to a larger copper surface to increase direct heat dissipation. These vents have a soothing effect on the Z-direction thermal stress. The 8-layer small board of the precision Daught Card, or on some BGA double-sided boards, often has such a venting hole arranged in a grid, and a gold-plated “heat sink” on both sides.

Throwing Power Distribution

Throwing Power Distribution When the electroplating is carried out, the work at the cathode is affected by its shape, resulting in “primary current distribution” (Primary Current) The unevenness of the distribution is caused by the difference in plating thickness. At this time, various organic additives (such as brighteners, leveling agents, wetting agents, etc.) are added to the bath to make the original high-current area of the cathode surface rapidly increase under the influence of various organic substances. Thick plating has a slowing effect,Thereby, the difference in plating thickness with the low current region is brought closer. The ability of the organic additive in the bath to improve the thickness distribution of the cathode is called the “distribution force” of the bath, which is a complex experimental result requiring a high degree of coordination. When the wet electrolytic process is anodized, the term “distribution force” is also applied to the work attached to the anode. Anode treatment such as aluminum is a common example.


Thermo-Via thermal hole refers to high-power parts such as large ICs on the circuit board. A lot of heat energy will occur during operation, and the assembly board must be This extra heat is dissipated to avoid damaging the life of the electronic device. One of the simple methods of heat dissipation is to use the surface of the large IC to fill the ground plate, deliberately add PTH, and direct the heat generated by the large IC to the large copper surface on the back of the board for heat dissipation. This type of through hole, which is dedicated to heat transfer and is not electrically conductive, is called Thermo-Via.

Tie Bar

Tie Bar shunt bar in the circuit board industry refers to the board surface after etching to obtain an independent line, if further plating is required, a conductive path must be added in advance to continue. For example, in the gold finger area On the copper surface, when nickel plating is applied, the current from the cathode rod can only be switched on by the special Bus Bar and Tie Bar. The two “tool lines” for temporary conduction are on the board. After completion, it will be cut off from the edge of the board.

The Tooling Feature

Tool refers to the board used in various production and assembly processes. Various markers for positioning, alignment, and reference, such as tool holes, reference points, cutting points, reference lines, positioning holes, positioning grooves, alignment marks, etc., are collectively referred to as “tool objects”.

Trace lines

wires refer to general wires or lines on the board, usually do not include through holes, ground, pads and rings.The terms used in the original text as “lines” are still Track, Line, Line Run, Conductor, etc.

Trim Line

Trim Line cutting line The periphery of the finished circuit board, the boundary line that should be followed when cutting the shape is called Trim Line.

True Position

True Position refers to the hole position of the board or the various features of the board surface, etc., which are located in the theoretical position of the design. Known as the true position. However, due to various graphic transfer and machining processes, error tolerances are hidden, and it is impossible for each piece to be accurate. When the board is completed, the quality can be accepted as long as the “target” is still within the radius tolerance of the required circular area (True Position Tolerance) without affecting the assembly and terminal functions.

Unsupported Hole

Unsupported Hole refers to the hole that is not used for conducting or inserting parts, and there is no copper plated hole. Usually, these NPTH apertures are mostly large, such as 125 mil lock screw holes. Yes.

Via Hole

vias refer to the board only for conductive interconnection purposes, and not the PTH of the soldered part. These vias have a “Through Via Hole” that runs through the entire board, a “Blind Via Hole” that is only connected to the board surface and not fully penetrated, and is not connected to the board. It is buried in the Buried Via Hole inside the board, etc. These complex partial through holes are made by sequential Sequential Lamination. This term is often referred to as “Via”. “.

Voltage Plane Clearance

When the plated through hole has to pass through the built-in voltage layer of the multilayer board, and does not want to be in contact with it, the circular open space can be etched first on the copper surface of the voltage layer. After pressing, the smaller hole is drilled in the slightly larger open space, and the PTH is further completed. At this time, between the copper wall of the tubular hole and the large copper surface of the voltage layer, there is an empty ring existing to be insulated. Called Clearance.

Voltage layer

voltage layer refers to the voltage required to drive various parts of the board, can be used by the board surface The common copper conductor area is supplied, or one layer is used as a voltage layer in the multilayer board. For example, one of the two inner layers of the four-layer board is a voltage layer (such as 5V or 12V), which is generally represented by a Vcc symbol. The other layer is Ground plane (Groung Plane). Usually, the voltage layer of the multi-layer board functions as the heat sinking and Shielding in addition to the voltage required to supply the parts.

Wiring Pattern

The wiring pattern refers to the “wiring” pattern on the board design, which is equivalent to Circuitry Pattern and Line Run Pattern.

Working Master

work master refers to the ratio of 1:1 size, can be used for the production of film negatives, and can be directly turned into production line The actual use of the negative film, this original negative film called Working Master. CAD Computer Aided Design ; computer aided design CAE Computer Aided Engineering ; computer aided engineering CAM Computer Aided Manufacturing ; computer aided manufacturing MLB Multilayer Board ;Multi-layer board (refers to PCB multi-layer board) PCB Printed Circuit Board; Printed circuit board (also known as PWB, which is Wiring in the middle, but is now more simply referred to as Printed Board. The mainland term is “printed circuit board”) SMOBC Solder Mask Over Bare Copper ; Green paint is printed directly on bare copper (ie tin plate).

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