1, annular="" ring="" hole ring

Refers to the copper ring that is flat on the surface of the board outside the wall of the through hole. This hole ring is often connected to the outside ground by a cross bridge on the inner deck 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 (independent point), etc., which are synonymous with this word.

2, Artwork negatives

In the circuit board industry, this word often refers to black and white negatives. As for the brown "Diazo Film", it is also named after Phototool. The negatives used in PCBs can be divided into "original negatives" Master Artwork and retreaded "working negatives" Working Artwork.

3, Basic Grid basic square

Refers to the vertical and horizontal grid of the layout of the conductor layout when the board is designed. The early grid spacing was 100 mils, and the basic grid spacing has now shrunk to 50 mils due to the prevalence of fine lines.

4, Blind Via Hole blind guide hole

In a complex multi-layer board, some of the vias are deliberately incompletely drilled because only a certain number of layers are interconnected. If one of the holes is connected to the hole ring of the outer layer, such as a cup The special hole in the dead end is called the Blind Hole.

5, Block Diagram circuit system block diagram

The assembled board and various required components are framed by square or rectangular empty frames on the design drawing, and various electrical symbols are used to contact each frame one by one to form a systematic structure. Figure.

6, Bomb Sight bullet

Originally referred to as the bombardment of the bomber. PCB In the production of the film, the target for the upper and lower alignment is also set in each corner for the purpose of alignment. The more precise official name should be called Photographers' Target.

7, Break-away panel can be broken

Refers to many small-area boards. For the convenience of plug-in, placement, soldering, etc. on the downstream assembly line, in the PCB process, it is combined on a large board for various processing. When finished, the knife is used to perform a partial cut between the individual small plates, but a few pieces of "strength" (Tie Bar or Break-away Tab) with sufficient strength are retained. A few holes are drilled between the sheet and the edge of the board; or the V-shaped notches are cut up and down to facilitate the assembly process, and the boards can be broken apart. This small board joint assembly method will become more and more in the future, and the IC card is an example.

8, Buried Via Hole buried hole

Refers to a partial via hole of a 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" with the outer layer board, and is called a buried guide hole or a buried hole.

9, Bus Bar

Multi-finger the cathode or anode rod itself on the plating bath, or the cable to which it is attached. In the circuit board of the "process", the outer edge of the gold finger is close to the edge of the board, the original one is used for communication (the gold plating operation must be covered), and another small piece (both for saving) It is necessary to reduce the area as much as possible. It is connected to 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.

10, CAD computer aided design

Computer Aided Design uses a special software and hardware to digitally layout the board and convert the digital data into an original film by an optical plotter. This kind of CAD is more accurate and convenient than the manual method for the pre-production engineering of the circuit board.

11, 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.

12, Clearance room, clearance, empty ring

It means that on the inner layers of the multi-layer board, if the conductor surface is not required to communicate with the hole wall of the through hole, the copper foil around the through hole can be etched away to form an empty ring, which is especially called "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.

13, Component Hole part hole

Refers to the through hole that is inserted into the foot of the board. The hole has an aperture of about 40 mil on average. Nowadays, after the SMT is popular, the large-caliber jack has been gradually reduced. Only a few of the gold pinholes of the connector need to be soldered, and most of the other SMD parts have been modified.

14, Component Side component surface

In the early days when the board was fully loaded with through-holes, the parts must be mounted on the front of the board, so it is also called 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.

15, Conductor Spacing conductor spacing

Refers to the conductor of a board surface, from its edge to the edge of the nearest conductor, the span of the insulating substrate surface covered, that is, the conductor spacing, or commonly known as the spacing. Also, the Conductor is a generic term for various forms of metal conductors on a board.

16, Contact Area contact resistance

On the board is the contact point of the gold finger and the connector, the resistance that appears when the current passes. 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.

17, Corner Mark corner mark

On the board's backsheet, special marks are often left 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).

18, Counterboring deep hole expansion, countersink

The circuit board can be screwed and fixed in the machine. The matching non-conducting hole (NPTH) must have a "reaming" that can accommodate the nut so that the entire screw can sink into the surface of the board. To reduce the obstacles caused by the appearance.

19. Crosshatching Crossing Area

Some large-area conductor areas on the board surface, in order to get better adhesion between the board surface and the green paint, often turn off some of the copper surface, leaving a number of crisscross cross lines. Such as the structure of the tennis racket, this will be able to solve 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.

20, Countersinking cone reaming, horn hole

It is another kind of screw hole for locking. It is mostly used in wood furniture and is rarely used in the precision electronics industry.

21, Crossection Area cross-sectional area

The size of the line cross-sectional area on the circuit board will directly affect its current-carrying capacity. Therefore, it should be listed first when designing. It often turns off some of the copper surface, leaving a number of criss-cross cross lines, such as tennis balls. The structure is the same, so that the large area of copper foil can be solved, and the floating crisis exists due to thermal expansion. The cross pattern obtained by etching is called Crosshatch, and this improvement is called Crosshatching.

22. Current-Carrying Capability

Refers to the wire on the board, which can continuously pass the maximum current intensity (amperes) under specified conditions without causing deterioration of the electrical and mechanical properties of the board. The maximum current amperage is The "current carrying capacity" of the line.

23. Datum Reference Baseline Reference

In the process of PCB manufacturing and inspection, in order to be able to correctly position the film pattern on the board surface, a certain point, line, or hole surface is selected as the reference for its figure, called Datum Point, Datum Line, Or Datum Level (Plane), also known as Datum Hole.

24, Dummy Land dummy pad

In order to grasp the height of the existing parts during assembly, the surface of the parts under the belly of some parts needs to be raised, so that the dispensing can have better adhesion. Generally, the etching technology of the board can be used to deliberately leave there. Dummy Land is used as a "fake copper pad" for padding without powering up. However, due to poor design on the board surface, a large area of copper-free substrate surface will appear, with a few through holes or lines. In order to avoid excessive current concentration of the independent conductors during copper plating, various non-functional dummy pads or false wires can be added, and some current is distributed during plating to make the current density of a few independent conductors. Not too high, these copper faces are also known as Dummy Conductors.

25, Edge Spacing board edge

Refers to the open space between the edge of the board and its "nearest conductor line". The purpose of this open space is to avoid the problem that the conductor is too close to the edge of the board and may be short-circuited with other parts of the machine. Special attention to this project. Generally, the shortcomings such as white edge layering of the board cannot penetrate into the half of the width of the "edge".

26, Edge-Board contact board gold finger

It is the exit of the whole board for external contact. Usually, there are two sides on the upper and lower sides of the board, which can be plugged into the matched board edge connectors.

27, Fan Out Wiring/Fan in Wiring fanout wiring / fan-in wiring

Refers to the wires and through-holes and other conductors drawn from the pads around the QFP, so that the soldered parts can be interconnected 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.

28, Fiducial Mark optical target, reference signal

For the downstream assembly of the board surface, it is convenient for the operation of the visual aid system. On the empty ground of the outer edge of each pad of the board assembly position, the large-scale IC adds a triangular "optical target" to the upper right and the lower left to assist. An example is the placement of the machine for optical positioning. The PCB process often adds more than two reference marks for the alignment of the film and the plate surface.

29, Fillet inner round fillet

Refers to two planes or two straight lines, in the case of an arc filled at its vertical intersection. 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.

30, Film negatives

Refers to the film of the existing line graphic. 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.

31. Fine Line Thin Line

According to the current technical standards, four lines between holes or an average line width of 5 to 6 mils or less are called thin lines.

32, Fine Pitch dense pitch, dense line distance, dense pad distance

Those with a Lead Pitch equal to or less than 0.635 mm (25 mil) are called a close distance.

33, Finger finger (continuous alignment of the board edge)

In order to enable the function of the whole assembly board to be externally contacted on the circuit board, a gold-plated continuous contact on the side of the board can be used to insert the clip on another system "female" continuous adapter to enable To achieve the purpose of interconnecting systems. The official name of Finger is "Edge-Board Contact".

34, Finishing finishing, final repair

Refers to the final modification or finishing work of various finished products to make the product more beautiful, protective, and textured. Metal Finishing refers to metal parts or products, which are specially treated to enhance the corrosion protection function and view, such as various plating layers, anodized coatings, organic or inorganic coatings, etc. It.

35, Form-to-List wiring instructions list

A list of written instructions that indicate various cabling systems.

36, Gerber Date, Gerber File

It is a series of complete software files developed by Gerber Company for the circuit board circuit graphics and holes. 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 is still not widely used.

37, 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 mils, which is based on the pitch of the "integrated circuit" (IC) pin. This Grid is approached to 50 mils or even 25 mils. Located at the intersection of the grid is called On Grid.

38, Ground Plane Clearance Grounding Empty Ring

"Integrated circuit breaker", whether it is a traditional IC or VLSI, its grounding or voltage pin is connected to the grounding layer (GND) or the voltage layer of the voltage layer (Vcc), and then "one bridge" or " The cross bridge is interconnected with the large copper surface outside. 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 clearing ring (the white ring in the figure) 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.

39, Ground plane (or Earth Plane) ground plane

It is a kind of board surface which belongs to the inner layer of the multi-layer board. Usually, a layer of the circuit board of the multi-layer board needs to be matched with a grounding layer of a large copper surface to be used as the grounding, shielding, and heat dissipation of the common circuit of many parts. (Heatsinking). 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.

40, Hole Density hole number density

Refers to the number of holes drilled in the unit area.

41, Indexing Hole reference hole, reference hole

Refers to the board in the manufacturing process in the corner of the board or the edge of the board to drill some tool holes, as other image transfer, drilling, or cutting shape, and the basic reference point of the pressing process, called Indexing Hole. Others have similar terms like Indexing Edge, Slot, Notch, and so on.

42. Inspection Overlay check film

It is a semi-transparent line of negative or positive film (such as Diazo's brown, green or blue), which can be used as a tool for visual inspection on the board. This method can be used for the first batch of tests. Visual inspection of the "First Article".

43, Key key slot, key

The former is a slotted notch at a certain position in the gold finger area on the circuit board. The purpose is to match another negative connector. A foolproof design that does not reverse when plugged in is called a 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.

44, Land hole ring pad, surface (square) pad

Before the SMT was introduced in the early days, when the traditional parts were soldered with their foot sockets, the hole rings on the outer surface of the board, in addition to being used as a relay station for conductive interconnections, can form a strong conical weld with the pins. point. 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.

45, Landless Hole ringless through hole

Refers to some densely packed boards. Since the board surface is required to be arranged with many lines and square pads of adhesive parts, there is little leftover space 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.

46, Laser Photogenerator (LPG), Laser Photoplotter laser exposure machine

Direct use of laser single-beam parallel light in conjunction with computer control to expose the original Artwork of the PCB to replace the original hand-made original large patch (Tape-up), and re-shrink The original negative film. 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.

47, Lay Out wiring, layout

Refers to the layout of the board at the time of design, the arrangement of each part in each level, and the overall layout of the wire, the position of the through hole, etc. is called Lay Out.

48, Layer to Layer Spacing interlayer distance

It refers to the distance between the two copper foil conductor layers of the multilayer board, or 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.

49. Master Drawing main picture

It refers to the main reference of various specifications in the manufacture of circuit boards. It also records the dimensions and special requirements of the various parts of the board, which is commonly known as the "blueprint", which 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.

50, Metal Halide Lamp metal halide lamp

Iodine is one of the halogens, and iodine is easily "sublimed" directly 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.