1, PADS Logic work space for (A).
A 56 inch x 56 inch x 65 inch B 65 inches. .
2, PADS Logic design grid is (A).
A Design Grid B Display Grid. .
3、显示栅格快捷键为 ( A )。.
A GD (XY) BG (XY) CD (XY). .
4. PADS Logic in Minimum display that (B).
A maximum display width B shows the minimum line width of C shows the design width. .
5, ext Encoding options when you enter text font format, to enter the Chinese font is (A).
A "Chinese Simplify" B "Chinese Traditional" C "Chinese Greek". .
6, not the parameters (Parameters) set (C).
A node (Tie Dot) B corner of the length of the bus (Bus Angle) C fonts (Fonts). .
PADS Logic 7, type a new symbol (B).
A 3 B 4 C 5. .
Pads Logic 8, there are several filter options (B).
A 7 B 8 C 9. .
9, Pads Logic import PCB button (A).
A Send net list B ECO TO pcb C ECO TO logic. .
10, Pads Logic in a system-provided in several ways (C).
A 1 B 2 C 3. .
11, PADS Layout has several types of raster (Grids) (A).
A 2 B 3 C 4. .
12, is in the Pads Layout system provides the unit conversion right (A).
A 1MM = 2. .54 MIL B 1CM = 2. .54 MIL C 1MIL = 2. .54 MM. .
13, Part package can contain many PCB packaging (A).
A open-B 3 个 C 4 个. .
14, PADS Layout used in the design process for a few kinds of job grid (Working Grids) (B).
A 2 B 4 C 6. .
15, the Layout system parameter to move Drag moves in several ways (B).
A 2 B 3 C 4. .
16, Pads Layout Pads logic and saying the wrong relationship is (C).
A can B could directly enter the Chinese Internet guide network C can not generate BOM file. .
17, circuit board design there are several middle-level setting (B).
A 2 B 3 C 4. .
18, circuit symbols move shortcuts (C).
A Ctrl + c B Ctrl + d C Ctrl + e. .
19, circuit design of the interface on the design tool does not contain (A).
A move to add new network element B position C position rotating components. .
20, PADS Layout file import Protel99 file is (B).
A. . TXT B. . ASC C. . DXF. .
21, circuit board design keyboard shortcuts to zoom out which of these is (C).
A Pause break B Page Up C Page Down. .
22, which of the following is the correct cursor automatically positioned on the R1 and highlighting (C).
A GGR1 B GSR1 C SSR1. .
23, mobile PCB line width minimum possible number of MM (A).
A 0. .1 B 0. .01 C 0. .001. .
24, Layout components in the package Wizard contains several forms (B).
A 5 B 6 C 7. .
25, EMC definition does not contain content is (C).
A EMI B EMS C EMB. .
26, EMC certification is China's icon is (B).
A FCC B CCC C CCF. .
27, circuit board design top silk in which layer (B).
A 25 layer B 26 level C 27 layer. .
28, reset circuit where true is (A).
A close location close to where the power supply IC B C close to where the interfaces. .
29, a 20MA differential-mode of the current 30MHZ, 3M Department of radiation field (B).
A 10uV / m B 100uV / m C 1000uV / m. .
30, PCB design of common mode current interpretation of the right (A).
A current equal and the same B current equal and opposite current size of the C range, in the same direction. .
Second, the indefinite (60 minutes, 2 minutes each).
1, the following components which are Pads Logic content attributes (AB). .
A PCB Decals B SigPins C Pad Stack。.
2 Which of the following is the format to import Pads Logic (ABC). .
A 。.TXT B OLE C 。.ECO。.
3 Which of the following is a set of content Pads Logic system (AB). .
A Global B Text C Grids。.
4, the definition of design rules (Design rules) contains (ABC). .
A safe spacing (clearance) B wiring (routing) C (constraints).
5 Which of the following design software can be directly and Pads Layout in the transconductance (A). .
A CAD B protel C ORCAD。.
6, Pads Logic can open the file suffix with (BC). .
A 。.ASC B 。.SCH C 。.DSN。.
7, Pads Layout system of units provided (ABC). .
A Mils B Metric C Inches。.
8, the following statement on the Pads Layout right there (B). .
You can directly open A file b can protel interconvertible CAD C can directly go difference line.
9, the following translation right there (AC). .
A bus (Bus) to paste the Cut = B C pages connected symbol (Off-Page).
10, Pads Layout system, the following translation right there (ABC). .
A Drag and move and whisk attacl said.
B Diagonal said alignment angle and bevel angle. .
C Select Board Outline indicates that the selection border.
11, PCB design modification tool box (ECO Toolbar) is right in there under (ABC). .
A component can be removed.
B components can be moved. .
C you can modify the network name.
12, the following statement right there (BC). .
2005. A .2 PADS to the latest design software PADS.
B PADS Layout of the ECO modifications can be modified into Logic where followers also have been. .
C PADS Router for PADS high-speed design window.
13, Layout design is right on the following function keys are (BC). .
A Page UP key is a narrow view.
B END key to refresh the design interface. .
C middle mouse scroll up and down around the interface.
14, Layout design is right on the pad layer definition of the (AC). .
A side-Mounted front pads size setting.
B Inner layers pad size for the second set. .
C Opposite side to back pad size setting.
15, 21-30 layer tourism activities on the right with (AC). .
Solder Mask A 21 storey as top remove Top green oil.
B 24 layer Dril Drawing for the pad layer. .
C 27-Assembly Drawing Top layer for top level segmentation.
16, pad attribute changes explain the right column there (ABC). .
A Drill hole size pads.
B Orientation rotation. .
C Diameter pads the size of the outer circle.
17, components corresponding to the correct label has (AB). .
A corresponding IC ANA.
B DIO corresponding diode. .
C IND corresponding transformers..
18, Layout in the package that the correct components are (AB). .
A DIP for inline elements.
B 0603, said chip components. .
C SO20WB expressed as 20PIN narrow Hugh.
19 SMT package, the wizard can do the main part (AB). .
A SOIC。.
B QUAD. .
C DIP。.
20, Layout of the following is right on the drawing mode is (AB). .
A select the pads pressing F2: represents the alignment.
B [Layer]: replace the current board level. .
C [Add Corner]: indicates that the increase in an arc.
21, Layout of the property changes on the drawing mode is right below the menu is (AB). .
A [Cycle]: select selected objects nearby objects.
B [Move]: Move the selected object. .
C [Route]: increased network alignment.
22, Layout of the automatic annotation model is right for (BC). .
A [Snap to Corner] capture dot.
B [Snap to Center] to capture both ends of the point where the center of the object. .
C [Snap to Circle/Arc] capture circle or arc.
23, PCB statement on engineering change model is not correct (BC). .
A component can be added and deleted.
B synchronization circuit diagram and PCB, the components can not be modified, so that PCB and route map will not be synchronized. .
C you can modify the component's label, the second the same components and you can modify the same label.
24, Layout of components on the tool is not correct to increase the (AB). .
A if the Layout diagram of components you can add a component to add the button.
B [All Libraries] that in some parts library to find components. .
C [Items] option indicates that the component name, the "*" represents any characters.
25, Layout tools for argument on the rules set the correct (BC). .
A enter the initial width of the line is set: Setup → Design → Rules ... → Default Clearance.
B rule set tool [Routing] The icon for the routing rules. .
C rule settings tool [Report] this icon to define the reporting rules.
26, PCB in the number of automatic re-tool is not correct for (AC). .
A automatically renumbered tools are all components to rejoin the new label.
B [TOP] and [Bottom] option group is set up, respectively [TOP] layer and [Bottom] layer renumbered. .
C [Start at] that represents the last component of the grade.
27, PCB design verification in the verification statement is not correct spacing (A). .
A [Net to All] is representation on the Board for all grid spacing for validation.
B [Keepout] that components of the strict quarantine rules to check the distance between the area of separation. .
C [Same Net] is representation on the same network as the object you want to make space..
28, PCB design verification on high-speed verification of the [Electrodynamic Check] dialog box, select the "TCK" network is not correct for (AB). .
A [Check Impedance] verify size.
B [Check Delay] verify the length. .
C [Check Loops] Verify loop.
29, PCB circuit board diagram on CAM output statement is not correct (BC). .
A CAM output-painted output, printouts, drawing output.
B size print than the output listed in Figure 5. .
C CAM output file types can be divided into 5 types, of which the [NC Drill] type inclusion in..
30, PCB dimension arrows on the right option group argument (BC). .
A [Arrow Length] set the length of the arrow.
B [Arrow Size] that set the arrow type. .
C [Tail Length] set the line width of the arrow.
Third, determine title (30 points, 1 point for each question). .
1 SPECCTRA translator (Translator) to provide to you the dialog box style of the command file editor, called a DO file editor (DO file editor). *。.
2 irrigation Copper Copper Copper Copper Pour and paste the difference is, the shape box Copper unfinished after all the shops within its copper, not avoid any of the networks and components to the experience. .
3 PADS Layout provides a PCB design overall physical dimensioning tools. You need standards and data tagging method, which can format for full control.
4 Dimension (Dimensions) is a unit of the original design basis, the set design units to inches (Inches). .
5 Verify designing (Verify Design) command allows you to check your design safe spacing (Clearance), connectivity (Connectivity), high-speed circuit (High Speed) and plane (Plane) error. *。.
6 plane layer (Plane) network with the primary identification of hot pad (Thermals) whether the plane layer (Plane) have been generated *. .
7 in order to demonstrate the EDC function, you can add a network 24MHz network length of the rules. *。.
8, no mode command (Modeless Commands) and the shortcut key (Shortcut Keys) *. .
9 PADS when Layout design files when opened, each source object changes, these are embedded (Embeded) of the target automatically update. *。.
10 CAE package (CAE Decal) is a two-dimensional line (2D Line) symbol, which represents the components of the logic function *. .
Enter the PIN 11 15 address input, 6 control input and 1 additional input pin composition.
Many CAE Decal than 12 square needs to be completed step by step manual. *. .
13 from the Editing Toolbar icon Decal, select toolbar (Toolbar), open the lower level tool bar.
14 observations are not stored view, when you open a new design file or exit the PADS Logic, has been captured in the observation of the view will not be deleted. .
15 the BOM (Bill of Materials) is the design in the component type of statistical and arranged, and the use of a certain format. *。.
Gerber output for MS Word 16 documents and other OLE applications, in general, we choose to include OLE target output to Gerber files or graphics output. .
17 PADS Logic OLE functionality allows your PADS Logic and cross between PADS-Layout. *。.
18 When the implementation of the cross-search (Cross Probing), the design of the application documents are to be controlled off. .
19 use PADS Logic OLE tools transmission network (Netlist) to PADS-Layout, you can avoid manual input and output netlist (Netlist). *。.
20 in PADS Logic, you can choose a set of components, one by one to move more components. *. .
21 BGA tool box is Pads Layout new tool box, but it is only used to BGA packaging design.
22 Set Grid (Grids) PADS Layout is a type of grid (Grids), the work of the grid (Working Grids). .
23 only pin (Pin)/gate (Gate) and the reference number (Ref. Des。.) Rename the inverse annotation from PADS-Layout to principle diagram *.
24 To be able to layer in the plane (Plane Layers) on the wiring, you need them from the routing rules defined to effectively remove the wiring layer. .
25 in order to easily separate plane layer (Splitting the Plane) is defined, you should close all unrelated layer display color. *。.
26 whether you will be the label (Label) on the package (Decal) of where, when you use the PCB package (PCB Decal) to add elements to the design, the reference number (Reference Designation) always occurs. *. .
27 in the Preview Gallery has several symbol type (Part types) for PCB packaging (PCB Decal) has been specified, but it has been established.
28 plate border (Board Outline) is used with the mapping project, copper and copper irrigation methods such as the establishment of the same polygon. *. .
29 if you make more complex shapes or some frame positioning holes, Auto CAD drawing frame shape and positioning of the hole, and then import from CAD to PADS Layout. *。.
30 PADS Layout of the input tools allow you to choose from Autodesk's AutoCAD or Parametric Technologies of Pro / ENGINEER product in the input data. *. .
* Correct.
4, short answers (30 points, 15 points per question). .
A, please describe the roadmap definition package (Decal) process to define a simple PIN (Pin Decal), they consist of a horizontal line and a circle composition.
1. . From the toolbar (Toolbar) select the package editor (Decal Editing) icon. .
2. from the package editing (Editing Decal) tool box, select create 2D line (Create 2D Line).
3. . By right mouse button opens a pop-up menu, then select the path (Path) method. .
4. Design by typing the G20 settings grid (Design Grid) is 20.
5. . The cursor on the origin mark, the status bar (Status Bar) in the X and Y coordinates will display zero. .
6. Press and release the left mouse button, you will begin to draw a line.
7. . Horizontal cursor until the coordinate directions for the X160, Y0 (check the status bar (Status Bar) confirmed seat..
Denominated), concatenate the left mouse button to finish the line.
8. . By right mouse button opens a pop-up menu, then select the circle (Circle) to change the graphics mode. .
9. You must pass a type S 180 0 indicates the center point of the circle.
10. . In order to define a circle, press the left mouse button and the cursor moves to the center of an outside. .
The design grid (Design Grid) (20 mils), and then press the left mouse button to complete the circle.
11. . From the toolbar, select Move mode (Move Mode) icon, and put markers in PINNOT package. .
(Decal) diagrams.
Save-pin package (Pin Decal). .
B, please indicate the bus wiring (Bus Route) the whole process.
1. . From the pop-up menu (Pop-up Menu) to select the midpoint of pin / through hole / mark (Select..
Pin/Vias/Tacks), to carry on the bus route (Bus Routing), restrict your choice.
2. . From the toolbar (Toolbar) select the design (Design) tool box icon. .
3. From the design (Design) tool box select bus wiring (Bus Route).
4. . To select a region, including the U2 (large SOIC device) of the three pins (just before us..
Surface highlighted three PIN) connected network connection.
Interactive bus route (Bus Routing) method is effective. If you use dynamic routing editor. .
(Dynamic Route Editing), single line operation, the corresponding to single line. Now you are corresponding.
Is the connection of multiple selected. .
Current wiring segments will be glued on the cursor and guide your wiring. Each time you add a wire.
A corner route (Route Corner) or through hole (Via), the bus will follow the other connection to it. .
5. From pin (Pin) to move, to add a vertical line, and press the Add button of the mouse.
A corner (Corner) as a guide way, observe bus (Bus) what other members of this match. .
Guidance direction.
6. . Move the cursor to the target pin (Pin) the following point on, add another corner (Corner), NOTE. .
Observation on the bus (Bus) and how is the other members of the guidance on the direction of the match.
7. . From the pop-up menu (Pop-up Menu) Select Done (Complete) command to complete the bus route. Bus. .
(Bus), all members will have complete wiring and smoothing (Smoothed).
Used hole shapes (Via Patterns) to bus route (Bus Routing). .
Bus wiring (Bus Routing) also has an automatic mode with a hole (Via Patterns), inserted into the hole.
(Vias) capabilities. When you add vias to a guide wire when wiring to bus members are wire. .
Add a hole (Vias).
PCB Design Engineer Intermediate examination papers (practical skills). .
(30 minutes each, for a total of 150 min).
First, in today's wireless communication devices, radio is often a small part of the outdoor unit structure, while the outdoor unit of the RF section, IF section, and the outdoor unit to monitor the low-frequency circuit parts are often deployed on the same PCB. Ask for such materials on the PCB layout requirements? How to prevent radio frequency, intermediate frequency and low frequency interference between each circuit? Modern high-speed PCB design, in order to ensure signal integrity, often require the input or output device for termination.How does the terminating? a termination is by what factors determine what rules of??.
1. . Hybrid circuit design is a big problem, it is difficult to have a perfect solution. General RF circuit in the system are carried out as an independent single board placement and routing, and even have special shielding chamber. And RF circuits are generally single or double panel, a relatively simple circuit, all of which are to reduce the distribution parameters of the RF circuit, RF system to improve consistency. In contrast to the FR4 material, the RF circuit board orientation and high Q value of the substrate, the dielectric constant of this material is relatively small, less transmission line distributed capacitance, high impedance, small signal transmission delay. .
In a mixed circuit design, RF, digital circuits in the same piece of PCB, but are generally divided into radio frequency circuits and digital circuits, respectively, the layout of the wiring. A hole between the Earth and shielding box shielding.
2. . Termination (terminal), also called matching. Generally in accordance with the matching sub-active position and end with matching matching. Which is generally the source resistance in series with matching matching, termination generally parallel match, way more, there is resistance on the pull, pull-down resistor, Thevenin match, AC matching, match the Schottky diode. Match the characteristics of using methods generally BUFFER, Top condition, level approach to determine the type and sentence, but also the duty cycle signal, system power consumption. Digital circuit is the most critical timing issue, plus match the purpose is to improve the signal quality, the decision can determine the time of the signal received。 For level effective signal, to ensure the establishment, maintenance time, signal quality and stability; the extension of a valid signal, to ensure signal monotonous, signal delay speed to meet demands.
Second, the circuit board fixed size case, if the design to accommodate more features they often need to increase the linear density PCB's Zou, 但是 There is potential for alignment of mutual Ganrao Daozhi increased Tongshi impedance traces too small also can not be reduced, will the high-speed (> 100MHz) high-density PCB design which skills? in the high-speed PCB design must take into account impedance matching to prevent reflection, but because of limited processing technology of PCB impedance continuity and simulation it is not fake that in the schematic design of how to consider this question? Also on the IBIS model, I do not know where to provide more accurate IBIS model base。 Our download library, most of which are not very accurate, very indicative of the simulation.
A: In high-speed high-density PCB design, the crosstalk (crosstalk interference) is indeed a special attention because of its timing (timing) and signal integrity (signal integrity) has a great influence. Here are a few caveats: 1. . Control the characteristic impedance of the continuous alignment and matching. 2. . Go line spacing size. General often see double spacing width. Can go through the simulation to know the line spacing on the timing and signal integrity effects, to identify the minimum tolerable distance.The results of different chip signal may be different. 3. Select the appropriate termination method. 4. avoid and the two-tier alignment direction is the same as, or even just the top and bottom lines overlap, because this kind of crosstalk ratio with the adjacent alignment scenario. 5. use of buried and blind hole (blind/buried via) to increase the alignment of the area. However, PCB production costs will increase. In practice it is very difficult to achieve completely parallel with, and so long, but still want to try to do it. In addition, you can set aside difference termination and common-mode termination, to ease the timing and impact of signal integrity.
In the design of high-speed PCB circuits, impedance matching is one of the design elements. The impedance method has the absolute alignment with the relationship, such as walking in the surface layer (microstrip) or the inner layer (stripline / double stripline), and the reference layer (power layer or stratum) of the distance, take line width, PCB materials, etc. will affect the alignment of the characteristic impedance value. That is to be determined after the wiring impedance.General simulation software line model or mathematical algorithms used by not taking into account some of the wiring resistance is not continuous, this time in the schematic diagram can only reserve some terminators (termination), such as in-line resistors, etc., to ease the alignment effect. Truly fundamental solution to the problem or wiring to avoid the occurrence of resistance is not continuous. IBIS model will have a direct impact on the accuracy of the simulation results. Basically, IBIS can be regarded as the actual chip I / O buffer electrical characteristics of the equivalent circuit of the information, usually obtained by the SPICE model transformation (can be used to measure, but more limited), while SPICE data and chip manufacturers have absolute relations, so as to provide a device of different chip makers, which SPICE data is different, and then converted the data within the IBIS model will follow another.In other words, if you use A manufacturer's device, only they have the ability to provide accurate information on their device model, because no other person will be better than their device is determined by what process. If vendors IBIS inaccurate, can only continue to require the manufacturer to improve is the fundamental solution.
Third, the high-speed PCB design software we use is simply to set a good EMC, EMI rules checking, and designers should take into account those aspects to EMC, EMI rules? How to set the rules? Walking near the level in the pcb on high-speed differential signal lines on the time, in the case of impedance matching, because the mutual coupling of two lines, will bring many benefits.But the view was expressed that this will increase the signal attenuation, affecting the transmission distance, why? I in some big company Evaluation Board on high-speed cabling are as close as possible to and parallel to, but intentional so that the two-line distance come, what effect will be even better? my signal 1GHz above, impedance of 50 ohms. In the calculation using the software, the difference is calculated as 50 ohm or to 100 ohms to? receiver difference between whether a matching resistor?.
A: General EMI / EMC design requires taking into account the radiation (radiated) and conduction (conducted) two aspects. . The former part attributable to the higher frequency (> 30MHz) the latter part of the lower frequency (<30MHz). . So we can not only pay attention to the neglect of low-frequency high-frequency part. .A good EMI/EMC design must first be taken into account when the layout of the device's location, PCB stacked arrangement, important online law, choice of devices, etc, if these do not advance a better arrangement, after the solution shibeigongban will increase costs. For example, the location of the clock generator as not to close the external connectors, high-speed signal to go as far as possible and pay attention to characteristics of the inner layer of continuous impedance matching with the reference to reduce the reflection, the device by pushing the signal slope (slew rate) as small as possible to reduce the high frequency components, select the decoupling (decoupling / bypass) capacitor frequency response when attention to its compliance with requirements to reduce the noise power level. . Also, note the high frequency signal current return path to circuit area as small as possible (that is, loop impedance loop impedance as small as possible) to reduce radiation. .You can also use the segmentation of the way to control the range of high-frequency noise. Finally, the appropriate choice of PCB and shell place (chassis ground).
Will cause high-frequency signal energy attenuation characteristics of first conductor resistance itself (conductor loss), including the skin effect (skin effect), the other dielectric materials dielectric loss. These two factors in the electromagnetic theory of transmission line effects (transmission line effect), they can see their impact on signal attenuation.Differential line coupling will affect their characteristic impedance, become smaller, according to the principle of partial pressure (voltage divider) this will make the signal source to the line voltage. As the result of coupling, signal attenuation of theoretical analysis I have not seen, so I can't comment. The difference on the wiring should be the appropriate way near and parallel. The so-called proper spacing near because it will affect the differential impedance (differential impedance) value, this value is the design of difference on the important parameters. Parallel is also required to maintain the differential impedance for consistency. If the two lines suddenly near or far, the differential impedance will be inconsistent, it will affect the signal integrity (signal integrity) and the time delay (timing delay). Differential impedance is calculated 2 (Z11 - Z12), which, Z11 is the impedance of the alignment itself, Z12 is because the coupling between the two differential line impedance generated, and the line from the. Therefore, to design differential impedance of 100 ohms, the impedance of the alignment itself must be larger than 50 ohms。 As for the large number of simulation software, you can work out. Receiving end of the difference between matching resistor will usually be added, its value should be equal to the value of the differential impedance. This signal quality will be better.
4, PCB design how to avoid high frequency noise? How to solve the high-speed PCB design layout and EMI Conflicts? Number of PCB component systems, the board should be how to connect between the ground? PCB design of differential signal lines can increase the middle ground? . .
1, avoid high-frequency interference of the basic idea is to reduce the high frequency signal interference electromagnetic field, which is the so-called crosstalk (Crosstalk). Availability La. ..
Large high-speed signal and the distance between the analog signal, or add ground guard / shunt traces in the analog signal next. Note also the number to. .
On analog noise interference.
2, due to the increase of the resistance and capacitance EMI or ferrite bead, can cause some electrical characteristics of the signal does not meet specifications. Therefore, the best. .
First Schedule alignment and PCB laminated skills to solve or reduce EMI problems, such as high-speed signal to go inside. Finally the resistance or capacitance.
ferrite bead means to reduce the damage signal. .
3, the PCB Board connected between the signal or power in action, for example, when A Board has power or signal send to B, there must have been on the Board.
The same amount of current flow back to A board from the ground (this is the Kirchoff current law). This formation will find resistance at the current minimum of the local stream. .
Back. Therefore, in all regardless of power or signal connected interfaces, assigned to strata pins cannot be too little, to lower the impedance,.
This can reduce the noise on the ground. Alternatively, you can analyze the entire current loop, especially the larger part of the current, adjust the ground or ground. .
The Add method to control the current law (for example, in the manufacture of low impedance somewhere, so most of the current walk from this place), on other more sensitive.
Sense signal. .
4, differential signaling intermediates are generally cannot be combined with the ground. Because of the differential signal applications the most important thing is to take advantage of the difference signal between coupling.
Joint (coupling) benefits, such as flux cancellation, noise (noise immunity) capability. If the middle ground,. .
Coupling effect will be destroyed.
5, PCB design, why shop copper? Pcb board is doing when, in order to reduce interference, ground and should constitute a closed form? In PCB design, usually divided into protected ground and signal ground; power to be further divided into land and analog to digital, why on earth. .
General shop copper has several reasons:.
1, EMC. . For large areas of land or power shop copper shielding will play the role of some special places, such as the PGND play a protective role. .
2, PCB processing requirements. General in order to guarantee the effectiveness of electroplating, or laminated non-deformation, for wiring a smaller shop copper PCB.
3, signal integrity requirements, to the high-frequency digital signal of a complete return path, and to reduce the DC network cabling. .
4 and, of course, heat, the special device installation requirements shop copper, etc..
Doing when the PCB board, in general, reduce the loop area should be in order to reduce interference, ground cloth when the cloth into the closed form should not be. .
Type, but the cloth into dendritic better, is to increase the area as possible.
The main purpose is to divide the land for EMC considerations, fear that the digital part of the power and ground noise will be other signals, particularly analog channel. .
# Interference through pathways. As for the signal and protection of land divided because EMC in ESD static discharge, similar to our lives.
The role of lightning rod grounding. No matter how divided, only one end of the earth. Only way to put a different noise diarrhea. .
IT test circuit board PCB engineer editing.
