CN103858526B - Circuit board and method for forming a circuit on a PCB - Google Patents
Circuit board and method for forming a circuit on a PCB Download PDFInfo
- Publication number
- CN103858526B CN103858526B CN201380003210.XA CN201380003210A CN103858526B CN 103858526 B CN103858526 B CN 103858526B CN 201380003210 A CN201380003210 A CN 201380003210A CN 103858526 B CN103858526 B CN 103858526B
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- Prior art keywords
- line
- shielding line
- differential lines
- shielding
- circuit
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Classifications
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/02—Details
- H05K1/0213—Electrical arrangements not otherwise provided for
- H05K1/0237—High frequency adaptations
- H05K1/0245—Lay-out of balanced signal pairs, e.g. differential lines or twisted lines
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/02—Details
- H05K1/0213—Electrical arrangements not otherwise provided for
- H05K1/0216—Reduction of cross-talk, noise or electromagnetic interference
- H05K1/0218—Reduction of cross-talk, noise or electromagnetic interference by printed shielding conductors, ground planes or power plane
- H05K1/0219—Printed shielding conductors for shielding around or between signal conductors, e.g. coplanar or coaxial printed shielding conductors
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- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
- Structure Of Printed Boards (AREA)
Abstract
A circuit board and a circuit design method are provided. A first shielded line is disposed between two parallel differential lines. The first shielded is an electric line in parallel with the differential lines and disposed on the symmetrical line of the two differential lines. Also a second shielded line and a third shielded line which are parallel each other are added. The second shielded line is symmetrical with the third shielded line relatively to the symmetric axis of the differential lines. A fourth shielded line is added, which is in vertical connection with the first shielded line, the second shielded line and the third shielded line. The fourth shielded line is symmetrical with the symmetric line of the two differential lines. External radiation of the differential lines is reduced through the shielded line structure.
Description
Technical field
The present invention relates to circuit field, reduce circuit electromagnetic interference technology particularly with regard to a kind of.
Background technology
With the continuous development of the communication technology, the operating rate of chip increases sharply, and the therefore electromagnetic radiation of generation can be right
Other electronic equipments cause electromagnetic interference.For example a lot of electronic products all can produce in the high frequency for 6GHz, 10.3125GHz for the speed
Raw obvious electromagnetic radiation.The reason produce these electromagnetic interference be：Passed by PCB trace from chip conducted noise out
Broadcast, be then propagate into all kinds of high speed connectors (such as back panel connector, hard disk connector), these connectors are all generally radiation
The stronger antenna of ability, conducted noise can be radiate by they, causes electromagnetic interference to other devices or equipment.
In order to meet the requirement of Electro Magnetic Compatibility (Electro Magnetic Compatibility, EMC) certification, existing
In technology, by the way of the shielding of whole machine.Whole machine shielding refers in equipment outer wrapping metal shell, relies on physical arrangement to be formed
Electrostatic screening effect come shielding high-speed connector to external radiation.But at high frequencies, even if the slit of very little also has
Significantly electromagnetic interference leaks out.And equipment cannot be to ensure that and fully seal, such as in order to meet cooling requirements, can be in machine
Air holes is opened on case, the way effect of therefore whole machine shielding is limited.
How a kind of new departure reducing differential lines electromagnetic interference is provided, is urgent problem.
Content of the invention
The embodiment of the present invention provides a kind of method forming circuit in wiring board and a kind of PCB substrate, can shield difference
The radiation of circuit.
In a first aspect, the embodiment of the present invention provides a kind of wiring board, it is laid with parallel two differential lines, between differential lines
There is the first shielding line, described first shielding line is the conductor wire parallel with differential lines, and be located at the line of symmetry of two differential lines
On.
In the first possible implementation of first aspect, also include between two differential lines：Secondary shielding line, with
Described first shielding line is parallel；3rd shielding line, symmetrical with respect to the line of symmetry of two differential lines with described secondary shielding line；With
And the 4th shielding line, and described first shielding line, described secondary shielding line and described 3rd shielding line is vertical is connected, and described
4th shielding line is symmetrical with respect to the line of symmetry of two articles of differential lines.
In the possible implementation of the second of first aspect, also include between two differential lines：Additional structure, described
Additional structure is connected with least one shielding line in described wiring board, and symmetrical with respect to the line of symmetry of two differential lines.
In the third possible implementation of first aspect, the length of the first shielding line is difference described in a quarter
Line noise signal wavelength.
Second aspect, the embodiment of the present invention provides a kind of method forming circuit in PCB substrate, and described substrate includes being situated between
Electric layer and conductive layer, including step：Form photosensitive material on the electrically conductive；Photosensitive material is carried out with Partial exposure, unexposed
Part forms line pattern, and described line pattern includes the first shielding line graph and two difference line graphs, two difference line charts
Shape is parallel to each other, the first shielding line figure be located at two described difference line graphs between, described first shielding line graph with described
Difference line graph is parallel, and described first shields and be located on the line of symmetry of two difference line graphs；Line pattern is formed
Cannot etched protective layer；Etch away logicalnot circuit visuals and form circuit, described circuit has parallel two differential lines,
There is the first shielding line between differential lines, described first shielding line is the wire parallel with described differential lines, and be located at two differences
On the line of symmetry of separated time.
In the first possible implementation of second aspect, also include between two described difference line graphs：Second
Shielding line graph, parallel with the described first shielding line graph；3rd shielding line graph, parallel with the described first shielding line graph,
Described secondary shielding line graph is symmetrical with respect to the line of symmetry of two articles of described differential lines with the described 3rd shielding line graph；4th screen
Cover line graph, line graph is vertical connects with the described first shielding line graph, described secondary shielding line graph and described 3rd shielding
Connect, and described 4th shielding line graph line is symmetrical with respect to the line of symmetry of two articles of described difference line graphs；Accordingly, described circuit
Including secondary shielding line, the 3rd shielding line and the 3rd shielding line.
In the possible implementation of the second of second aspect, also include additional structure figure, additional structure figure with
In described line pattern, at least one shielding line graph connects, and symmetrical with respect to the line of symmetry of two described difference line graphs；
Accordingly, also include additional structure in described circuit.
In the third possible implementation of second aspect, described first shielding line is differential lines described in a quarter
The integral multiple of noise signal wavelength.
The implementation method of the application present invention, can reduce the external electromagnetic interference of differential lines.
Brief description
In order to be illustrated more clearly that the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing
Have technology description in required use accompanying drawing be briefly described it should be apparent that, drawings in the following description are these
Some bright embodiments, for those of ordinary skill in the art, without having to pay creative labor, acceptable
Other accompanying drawings are obtained according to these accompanying drawings.
Figure 1A is circuit embodiment schematic diagram of the present invention；
Figure 1B is circuit embodiment schematic diagram of the present invention；
Fig. 2 is circuit embodiment schematic diagram of the present invention；
Fig. 3 A is circuit embodiment schematic diagram of the present invention；
Fig. 3 B is circuit embodiment schematic diagram of the present invention；
Fig. 4 forms the embodiment of the method flow chart of circuit for the present invention in PCB substrate.
Specific embodiment
Purpose, technical scheme and advantage for making the embodiment of the present invention are clearer, below in conjunction with the embodiment of the present invention
In accompanying drawing, the technical scheme in the embodiment of the present invention is clearly and completely described it is clear that described embodiment is
The a part of embodiment of the present invention, rather than whole embodiments.Based on the embodiment in the present invention, the every other reality being obtained
Apply example, broadly fall into the scope of protection of the invention.
Differential signal, some are also referred to as differential wave, just the same with two, opposite polarity holding wire transmission of one line number
According to dependence two signal line level differences carry out the judgement of signal.Keep the parallel of two differential lines in wiring, can be bigger
Ensure the consistent of two signal line.Certainly, in practical engineering application, absolute parallel cannot accomplish, distance between centers of tracks is basic
Keep the constant requirement also complying with the embodiment of the present invention, such as between two differential lines or a certain section of two differential lines of folder
Angle is less than 5 °.Same group of two differential lines, one is properly termed as P line, and in addition one is properly termed as N line, between differential lines
Axial symmetry, the line of symmetry of differential lines is also referred to as axis.Differential lines are also referred to as differential signal line.
Due between same group of two differential lines, there is coupling, when the external world has noise jamming, almost simultaneously
It is coupled in two lines, and the recipient of signal is only concerned the difference of two signals, so the common-mode noise in the external world can be by
Offset.
Differential lines can a certain degree of suppression EMI because the opposite polarity of two signal line, they are to extraradial electricity
Can cancel out each other in magnetic field.But still there is a small amount of radiation product in practical situations both, especially when signal frequency is higher, right
There is outward obvious radiation.In the embodiment of the present invention, shielding construction can be a shielding line, or the combination of a plurality of shielding line, or
Person's shielding line is combined with additional structure, shields the noise of differential signal by shielding construction, suppresses EMI, reduces to external radiation
Generation.The shielding line mentioned in the embodiment of the present invention, shielding construction, the material of additional structure are all conductive materials, for example
Use copper as material.
Whole machine shield technology of the prior art has shortcomings, on the one hand because inevasible gap, through hole can shadows
Ring shield effectiveness；On the other hand, metal shell increased the volume and weight of equipment；Furthermore, consume more metal materials,
Also result in the raising of cost, and be unfavorable for environmental protection.
Figure 1A is an a kind of embodiment of circuit of the present invention.As shown in figure 1, wire 11a and wire 11b forms one group of difference
Separated time, is provided with the first shielding line 21 between differential lines.In the embodiment of the present invention, shielding line is located between differential lines and does not include shielding
The situation that line is connected with differential lines.
The via 22 of ground connection can be had on the first shielding line 21.
Wire 11a and wire 11b, in differential signal transmission, can produce noise signal and cause to external radiation.First shielding
The length of line can be a quarter noise signal wavelength, can suppress differential lines to external radiation.According to the theory of transmission line,
The open-circuit line of 1/4 wavelength is equivalent to a series resonant circuit, and load is in resistive.In other embodiments, the first shielding line
Length can be a quarter noise signal wavelength integral multiple, if the wavelength of noise signal is represented with λ, the first shielding line
Length can be 1/4 λ integral multiple, such as 1/4 λ, 3/4 λ or 5/4 λ.The value of λ can be determined by formula C=λ f.Its
Middle C is the light velocity, and f is the frequency of noise signal, due to the circuit design complexity of itself, it is also possible to pass through in implementing
Emulate and to obtain the length of the first shielding line, now the length of the first shielding line can not use the length of the integral multiple of 1/4 λ,
And be defined by emulating the length obtaining.
Figure 1B is another embodiment of the present invention, and a certain section in a pair of differential lines a part of in other words, can expand
The distance between differential lines.So can more easily lay the various shielding lines including the first shielding line.This way
Equally applicable to other embodiment.Increase way of example, the differential lines of can be stretched it is also possible to two all stretch, figure
The mode of 1B is that two differential lines all stretch.
Referring to Fig. 2, it is another embodiment of the present invention, the present embodiment, on the basis of the first shielding line 21, increased
Two shielding lines 31, the 3rd shielding line 32 and the 4th shielding line 33.Wherein secondary shielding line 31 is parallel with the first shielding line 21, the
Three shielding lines 32 are parallel with the first shielding line 21.4th shielding line 33 and the first shielding line 21, secondary shielding line 31 and the 3rd
Shielding line 32 vertically connects.Symmetrical also relative to the line of symmetry of differential lines between secondary shielding line 31 and the 3rd shielding line 32.
In this embodiment, the size of each bar shielding line can be more shorter than the first two embodiment, for example each bar shielding line
Length can than 1/4 λ little an order of magnitude.Between first shielding line 31 and differential lines 11a and secondary shielding line 32 with poor
Be equivalent between separated time 11b and define electric capacity.And the first shielding line 21 and the 4th shielding line 33 are equivalent to inductance.This four shieldings
In line, the length of every shielding line, different according to noise frequency difference, its concrete numerical value can obtain according to emulation, work as screen
Cover the resonance frequency of line and differential lines noise frequency same or like when, noise can be suppressed.Likewise, the first shielding line
Can there is no ground via, it is possibility to have the via 22 of one or more ground connection on 21.
In embodiments of the present invention, one or more additional structure can be increased on the basis of above-described embodiment, newly
The additional structure increasing is symmetrical with respect to the line of symmetry of differential lines, and connects with original shielding cable architecture.Additional structure can have
Via can also not have via, and via is symmetrical with respect to the line of symmetry of differential lines.Such as Fig. 3 A is another embodiment of the present invention,
This embodiment is to increased shielding line 34 with respect to the difference of a upper embodiment.Fig. 3 B compares with Fig. 3 A, and distinctive points are shieldings
Line 34 becomes shielding line 35.Shielding line 34 and shielding line 35 broadly fall into additional structure, and its common ground is with respect to differential lines
Line of symmetry is symmetrical.If kept, former shielding line is constant, and after increased additional structure, resonance frequency changes, and needs to emulate again
To determine new resonance frequency.
The embodiment of the present invention also provides a kind of method forming circuit, can form above-mentioned inclusion shielding in PCB substrate
The circuit of structure, substrate includes dielectric layer and conductive layer.The concrete structure of shielding line is referring to previous embodiment.
The method that the present embodiment forms circuit comprises the following steps：S1. form photosensitive material on the electrically conductive；S2. to sense
Luminescent material carries out Partial exposure, and unexposed part forms line pattern, the circuit phase that the shape of line pattern is made with hope
With line pattern includes shielding line graph and one group of difference line graph, and two difference line graphs are parallel to each other, difference line graph
Between include shielding line graph, described shielding line graph is the line segment parallel with difference line graph, and be located at two difference
On the line of symmetry of line graph；S3. being formed on line pattern cannot etched protective layer；S4. etch away logicalnot circuit figure portion
Divide and form circuit, described circuit has parallel two differential lines, between differential lines, has the first shielding line, described first shielding line
It is the line segment parallel with differential lines, and on the line of symmetry of two differential lines.The length of the first shielding line can 1/4 be made an uproar
Sound wave is long.
Understand, except the first shielding line, the shielding construction between differential lines can also be a plurality of screen in the embodiment of circuit
Cover the combination of line, the such as first shielding line, secondary shielding line, the 3rd shielding line are combined with the 4th shielding line, a plurality of shielding line
Combination formed shielding construction resonance frequency identical with difference signal noise frequency.Can also include attached outside shielding construction
Plus structure.
The method of above-mentioned formation circuit can be completed by a kind of device, and this device includes CPU and computer-readable medium,
CPU can execute the program in internal memory, thus completing the step forming the method for circuit.
The all or part of step realizing the embodiment of the method for above-mentioned formation circuit can be hard by programmed instruction correlation
Completing, aforesaid program can be stored in a computer read/write memory medium part, this program upon execution, execute including
The step of said method embodiment；And aforesaid storage medium includes：ROM, RAM, magnetic disc or CD etc. are various can be stored
The medium of program code.
Finally it should be noted that：Above example only in order to technical scheme to be described, is not intended to limit.Reference
Previous embodiment has been described in detail to the present invention, and the technical scheme described in foregoing embodiments can be repaiied
Change, or equivalent is carried out to wherein some technical characteristics；And these modifications or replacement, do not make appropriate technical solution
Essence departs from the spirit and scope of various embodiments of the present invention technical scheme.
Claims (10)
1. a kind of wiring board, be laid with parallel two differential lines it is characterised in that：
There is the first shielding line, described first shielding line is the conduction parallel with described two differential lines between described two differential lines
Line, and be located on the line of symmetry of described two differential lines, the resonance frequency of described first shielding line and described two differential lines
Noise frequency same or like.
2. wiring board as claimed in claim 1 is it is characterised in that also include between described two differential lines：
Secondary shielding line, parallel with described first shielding line；
3rd shielding line, symmetrical with respect to the line of symmetry of described two differential lines with described secondary shielding line；
4th shielding line, and described first shielding line, described secondary shielding line and described 3rd shielding line is vertical is connected, and institute
State the 4th shielding line symmetrical with respect to the line of symmetry of described two articles of differential lines.
3. wiring board as claimed in claim 1 or 2 is it is characterised in that also include between described two differential lines：
At least one via, described via is located on described first shielding line.
4. wiring board as claimed in claim 1 or 2 is it is characterised in that also include between described two differential lines：
Additional structure, described additional structure is connected with least one shielding line in described wiring board, and with respect to described two differences
The line of symmetry of separated time is symmetrical.
5. wiring board as claimed in claim 1, its feature exists：
The length of described first shielding line is the noise signal wavelength of two differential lines described in a quarter.
6. wiring board as claimed in claim 1, its feature exists：
The length of described first shielding line is the integral multiple of the noise signal wavelength of two differential lines described in a quarter.
7. a kind of method that circuit is formed on PCB substrate, described substrate include dielectric layer and conductive layer it is characterised in that：
Form photosensitive material on the electrically conductive；
Photosensitive material is carried out with Partial exposure, unexposed part forms line pattern, and described line pattern includes the first shielding
Line graph and two difference line graphs, described two difference line graphs are parallel to each other, and the first shielding line figure is located at described two
Between difference line graph, described first shielding line graph is parallel with described two difference line graphs, and described first shields and position
On the line of symmetry of described two difference line graphs；
Being formed on line pattern cannot etched protective layer；
Etch away logicalnot circuit visuals and form circuit, described circuit has parallel two differential lines, described two differential lines
Between have the first shielding line, described first shielding line is the wire parallel with described two differential lines, and be located at described two
On the line of symmetry of differential lines.
8. the as claimed in claim 7 method forming circuit in PCB substrate is it is characterised in that described two difference line charts
Also include between shape：
Secondary shielding line graph, parallel with the described first shielding line graph；
3rd shielding line graph, parallel with the described first shielding line graph, described secondary shielding line graph shields with the described 3rd
Line graph is symmetrical with respect to the line of symmetry of described two differential lines；
4th shielding line graph, with the described first shielding line graph, described secondary shielding line graph and described 3rd shielding line
Figure vertically connects, and described 4th shielding line graph line is symmetrical with respect to the line of symmetry of described two articles of difference line graphs；
Accordingly, described circuit includes secondary shielding line, the 3rd shielding line and the 3rd shielding line.
9. the method for circuit is formed as claimed in claim 7 or 8 on PCB substrate it is characterised in that described two differential lines
Also include between figure：
Additional structure figure, is connected with least one shielding line graph in described line pattern, and with respect to described two difference
The line of symmetry of line graph is symmetrical；
Accordingly, also include additional structure in described circuit.
10. the method forming circuit in PCB substrate as claimed in claim 7, its feature exists：
Described first shielding line is the integral multiple of the noise signal wavelength of two differential lines described in a quarter.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/CN2013/076158 WO2014186966A1 (en) | 2013-05-23 | 2013-05-23 | Circuit board and method for forming circuit on pcb |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103858526A CN103858526A (en) | 2014-06-11 |
| CN103858526B true CN103858526B (en) | 2017-02-08 |
Family
ID=50864364
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201380003210.XA Active CN103858526B (en) | 2013-05-23 | 2013-05-23 | Circuit board and method for forming a circuit on a PCB |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN103858526B (en) |
| WO (1) | WO2014186966A1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108076580B (en) * | 2016-11-15 | 2021-01-22 | 中兴通讯股份有限公司 | Method and device for isolating crosstalk between signal via holes |
| CN107995776A (en) * | 2017-12-14 | 2018-05-04 | 武汉电信器件有限公司 | A kind of circuit board and crosstalk eliminating method for being used to shield crosstalk |
| JP7084245B2 (en) * | 2018-08-02 | 2022-06-14 | 日本ルメンタム株式会社 | Printed circuit boards, optical modules, and optical transmission equipment |
| CN113727513B (en) * | 2021-07-27 | 2024-01-09 | 平头哥(上海)半导体技术有限公司 | Package substrate, printed circuit board, package device, and electronic apparatus |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4835188B2 (en) * | 2006-02-16 | 2011-12-14 | 日本電気株式会社 | Multilayer printed circuit board |
| CN101472385A (en) * | 2007-12-26 | 2009-07-01 | 鸿富锦精密工业（深圳）有限公司 | Printed circuit board |
| JP5409776B2 (en) * | 2009-03-30 | 2014-02-05 | パナソニック株式会社 | Flexible cable and transmission system |
| TWI387407B (en) * | 2009-06-10 | 2013-02-21 | Htc Corp | Flexible printed circuit and fabrication method thereof |
| CN101932188B (en) * | 2009-06-18 | 2013-05-08 | 宏达国际电子股份有限公司 | Flexible printed circuit board and its composition method |
| CN102711362A (en) * | 2011-03-28 | 2012-10-03 | 鸿富锦精密工业（深圳）有限公司 | Printed circuit board |
| TWI463940B (en) * | 2011-08-31 | 2014-12-01 | 中原大學 | Weak-coupling structure of differential-mode transmission line |
-
2013
- 2013-05-23 CN CN201380003210.XA patent/CN103858526B/en active Active
- 2013-05-23 WO PCT/CN2013/076158 patent/WO2014186966A1/en active Application Filing
Also Published As
| Publication number | Publication date |
|---|---|
| CN103858526A (en) | 2014-06-11 |
| WO2014186966A1 (en) | 2014-11-27 |
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Effective date of registration: 20211223 Address after: 450046 Floor 9, building 1, Zhengshang Boya Plaza, Longzihu wisdom Island, Zhengdong New Area, Zhengzhou City, Henan Province Patentee after: xFusion Digital Technologies Co., Ltd. Address before: 518129 Bantian HUAWEI headquarters office building, Longgang District, Guangdong, Shenzhen Patentee before: HUAWEI TECHNOLOGIES Co.,Ltd. |