Some tips of PCB design
Author:Chen Chunyan Time:2021-06-09 17:59 Browse(335)
PCB design tips, touch screen and OLED Forum
When beginners are drawing PCB, they should check the following basic principles one by one while wiring. After wiring, they should check the rules again.
for a long time.
there must be effect.

Some tips of PCB design

the ancients said: walking on.
ice till.
things in the world.
after all, there are few geniuses. Only by persevering can they achieve results.
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L: ''k [experience] 1: the principle of the schematic diagram is to facilitate wiring and troubleshooting, use the bus reasonably, and use the real pin distribution.
2   ' J    Q% s/ u' H; x+ r5 O6 R* U6 t6 n" j% u; L / v [experience] 2: before PCB generation, all unfamiliar device packages should be made by hand.
triode packages should be made in advance.
1   . 3 g! X3 c4 L9 @3 j- v7 Z' R   | 3 j7 s( R% r[experience] 3: hand sketching should be done before wiring.
the general layout should be carried out under the principle of performance first.
the layout should be based on the principle of performance first   .# d7 |; Z6 _ 6 G$ CY0 K.
Y8 n [experience] 4: the wiring should not be parallel to the axis of the component, the ground wire should be carefully set, and the comprehensive or grid copper coating should be used appropriately.
Y8 n [experience] 4    8 S; i. F1 X; ]" P- U5 n5 h2 ]$ R/ ?[experience] 5: in digital circuit, the ground wire should be a network.
the signal clock wire should be used reasonably, and the snaking wire should be used properly, and the pad should be appropriate.
the signal clock wire should be used reasonably   ' ]. A! e" T) r+ {7 Z: M! k6 b8 g    [experience] 6: manual wiring should be based on network or componentsThen, the docking and arrangement among the blocks are carried out.
the results show that the method is simple and effective   .
j1 b# Y/ ]5 W9 c# v& o' v! X* x[experience] 7: when editing a layout in an emergency, you must be calm. Generally, you only need to modify individual components or one or two networks.
when editing a layout in an emergency, you must be calm   . 1 y' ]0 `( @/ w' `6 [/ `' a6 }% V6 ?% Z6 s [experience] 8: when making PCB, at least five welding holes should be left in the blank space.
four corners and the center should be used for hole alignment.
when making PCB, there should be at least five welding holes in the blank space   # z5 U) y3 I.
S- k/ v6 m& U6 E& c: \[experience] 9: it's better to brush tin before welding, put the components on the board first, fix them with adhesive tape, and then weld them.
this is the first time for us to finish welding    3 S6 e% `( i4 U3 j& A4 t. g (P + E3 X1 X. ` 4 E.
e% V4 ^ 9 Q [experience] 10: the routing of ADC circuit should be separated from the routing of other digital circuits or signal lines (especially clock), and parallel and crossing are strictly prohibited.
in this paper, the design of ADC circuit is introduced   .* d! a" J! I' N: X / L7 N7 E0 O8 v% n [experience] 11: the oscillating crystal should be as short as possible.
and surrounded by a ground wire, but pay attention not to increase the load capacitance due to too small spacing.
1   .( f/ W6 a! z% V6 D2 Q! ?! Y "@ 4 '(L + y5h - n [experience] 12: single and double-sided boards should have at least 50% metal layers.
multilayer boards should have at least four metal layers to prevent local overheating and fire  .+ [ 2 W. U' g2 d! {" ?" m+ C; a# o7 D- p+ L' {* g4 }[experience] 13: the signal line should be uniform and short as far as possible.
the ground wire should be added between the signal line and the input / output line, and the ground wire should also be clamped between the modules.
the ground wire should be clamped between the signal line and the input / output line   . 3 X5 f2 s! l! i$ t6 a- \0 T    b8 k2 O    V (H [experience] 14: when the device pin contacts the ground wire, it is better to use grid instead of large area copper coating.
in order to prevent peeling, the whole board should also use grid    2 s4 _ 6 p% \' {1 C# j/ z( E: '& v.
s% O: ~ + P / C1 E4 R [experience] 15: if there is a large area of copper coating on the PCB board, a few small holes should be opened on the ground, but the holes should not be larger than 3.5mm, which is equivalent to the grid.
the hole should not be larger than 3.5mm   . 4 T8 b- |2 T1 e+ q4 |9 ]9 x! U * {7 d & x [experience] 16: when jumper is used to avoid too long wiring.
the jumper should not be placed under the IC integrated block and other large devices, so as to facilitate plug-in.
the jumper should not be placed under the IC integrated block and other large devices   .' j: p) v.
\# p" ^    O'E7 K% m $` 1 {5 @ "B [experience] 17: the heat dissipation and ventilation of the device should be fully considered in the layout and wiring, the heat source should be close to the edge of the board, and the distance between the test points should be designed.
the results show that the heat dissipation and ventilation of the device should be fully considered in the layout and wiring   / I8 U7 h2 g5 e7 l1 Z" c    S # B4 x0 X.
] 7} [experience] 18: 20h rule and 3W rule should be applied in multi-layer anti electromagnetic interference design,To overcome the boundary radiation coupling and logic current flux interference    8 C0 r% ^% F* ?' D$ U% F7 W5 T3 P' B6 e4 y1 ? 0 y [experience] 19: it is better not to use double signal lines in the same current direction.
and the minimum parallel length should be controlled, such as jog line or sine and cosine line   $ W. G& j7 N3 Y" d4 h" e- T! ?$ o* l[experience] 20: the interference caused by the change of the upper and lower edges of the signal in the low-frequency line is much greater than that caused by the frequency.
therefore, we should also pay attention to the crosstalk problem.
in this paper, the crosstalk problem is analyzed   . 7 x$ W2 G6 Q1 L& S+ D: z' B    A! D / D9 n [experience] 21: high speed signal line should be added with appropriate termination matching.
it is better to keep its impedance unchanged during transmission, and widen the line width as much as possible.
in addition, it is better to keep the impedance unchanged during transmission   . 7 Q8 t+ }4 }    S% B6 ?( Z; g! S: L+ e# E# ].
n[experience] 22: don't forget to add filter and coupling capacitor between the power supply and the ground of the integrated circuit block to eliminate the interference.
in order to eliminate the interference, it is necessary to add filter and coupling capacitor between the power supply and the ground of the integrated circuit block( X" Y! o4 C: |1 c6 _ These are some tips for PCB design.
PCB proofing can be downloaded www.jiepei.com/g588 Register to order, first order free proofing   .. R. Z: \( r3 m: ]( J0 P0 u. u1 S: d2 w: G* \& l9 g; M with the increasing density of modern integrated devices, the layout of PCB directly affects the performance of products,Even the key to the success or failure of the design.
as an electronic expert said, there may be countless permutations for ten kinds of devices.
but if there is a little error, its performance may be 100 times apart! The importance and technicality of PCB layout can be seen.
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