Ishicilelwe yiBhodi yeSekethe (PCB), eyaziwa ngokuba yiBhodi yeSekethe eShicileleyo (PCB), isetyenziselwa ukudibanisa nokusebenza amacandelo e-elektroniki kwaye iyinxalenye ebalulekileyo yoyilo lweSekethe yamandla. Eli nqaku liza kwazisa imithetho esisiseko yoyilo lwePCB kunye neengcingo.

Iinkcukacha imithetho esisiseko PCB ibhodi layout kunye nocingo

Basic rules of component layout

1. According to the layout of circuit modules, the related circuit to achieve the same function is called a module, the components in the circuit module should adopt the principle of nearby concentration, and the digital circuit and analog circuit should be separated;

2. Izixhobo, izixhobo kunye nezikrufu aziyi kufakwa ngaphakathi kwe-3.5mm (ye-M2.5) kunye ne-4mm (ye-M3) malunga nemingxuma enganyukiyo njengemingxuma yokubeka kunye nemingxuma eqhelekileyo ngaphakathi kwe-1.27mm;

3. Horizontal resistance, inductor (plug-in), electrolytic capacitor and other components under the cloth hole, so as to avoid the wave soldering hole and component shell short circuit;

4. Inxalenye yangaphandle yecandelo i-5mm kude nomda weplate;

5. The distance between the outer side of the pad of mounting element and the outer side of the adjacent inserting element is greater than 2mm;

6. Izixhobo zegobolondo zensimbi kunye nentsimbi (iibhokisi zokukhusela, njl.) azikwazi ukuchukumisa ezinye izinto, azikwazi ukusondela kumgca oprintiweyo, ipad, isithuba kufuneka sibe ngaphezu kwe-2mm. The size of positioning holes, fastener mounting holes, elliptic holes and other square holes in the plate is greater than 3mm from the plate side;

7. Izinto ezifudumalayo akufanele zisondele kwiingcingo kunye nezixhobo ze-thermal; Izixhobo zokushisa okuphezulu kufuneka zihanjiswe ngokulinganayo;

8. Isokethi yamandla mayicwangciswe ijikeleze ibhodi eprintiweyo kangangoko kunokwenzeka, kwaye i-wiring terminal yesokethi yamandla kunye nebhasi yebhasi edityaniswe kuyo kufuneka icwangciswe kwicala elinye. Ngokukodwa, musa ukubeka iisokethi zamandla kunye nezinye izihlanganisi ze-welding phakathi kwezihlanganisi ukuququzelela ukuwelda kwezi sokethi kunye nezihlanganisi kunye noyilo kunye nocingo lweentambo zombane. Ukwahlukana kweziseko zamandla kunye nezixhumi ze-welding kufuneka ziqwalaselwe ukuququzelela ukufakwa kunye nokususwa kweeplagi zamandla;

9. Uyilo lwamanye amalungu:

All IC components should be aligned unilaterally, and polarity marks of polar components should be clear. Polarity marks on the same printed board should not be more than two directions. When two directions appear, the two directions should be perpendicular to each other.

10, the surface wiring should be properly dense, when the density difference is too large should be filled with mesh copper foil, the grid is greater than 8mil (or 0.2mm);

11, the patch pad can not have through holes, so as to avoid the loss of solder paste resulting in virtual welding components. Umgca wesiginali obalulekileyo awuvumelekanga ukuba udlule kunyawo olusisiseko;

I-12, ulungelelwaniso olusecaleni, isikhokelo somlinganiswa esingaguqukiyo, indlela yokupakisha engaguqukiyo;

13. Polar devices should be marked in the same direction as far as possible on the same board.

Emibini, imithetho yecandelo locingo

1. Dweba indawo yocingo ngaphakathi kwendawo ≤1mm ukusuka kumda webhodi yePCB, kwaye ngaphakathi kwe-1mm ejikeleze umngxuma wokunyuka, kwaye unqande i-wiring;

2. Umtya wombane ubanzi kangangoko, awufanele ube ngaphantsi kwe-18mil; Ububanzi bomgca womqondiso akufunekanga bube ngaphantsi kwe-12mil; CPU incoming and outgoing lines should not be less than 10mil (or 8mil); Isithuba somgca singabi ngaphantsi kwe-10mil;

3. Umngxuma oqhelekileyo awukho ngaphantsi kwe-30mil;

4. Faka umgca ophindwe kabini: pad 60mil, indawo yokuvula i-40mil;

1 / 4W ukumelana: 51 * 55mil (0805 sheet); I-pad yokufaka ngokuthe ngqo 62mil, indawo yokuvula i-42mil;

I-capacitor engekho-polar: 51 * 55mil (iphepha le-0805); I-pad yokufaka ngokuthe ngqo 50mil, indawo yokuvula i-28mil;

5. Qaphela ukuba iintambo zamandla kunye neentambo zomhlaba kufuneka zibe yi-radial kangangoko kunokwenzeka, kwaye iintambo zesignali akufanele ziboshwe.

Indlela yokuphucula amandla okuthintela ukuphazamiseka kunye nokuhambelana kwe-electromagnetic?

Ungabuphucula njani ubuchule bokuchasana nokuphazamiseka kunye nokuhambelana kombane xa usenza iimveliso zombane kunye neprosesa?

1. Ezinye zezisistim zilandelayo kufuneka zinike ingqwalasela eyodwa kuphazamiseko lwe-anti-electromagnetic:

(1) i-microcontroller clock frequency iphezulu kakhulu, umjikelo webhasi yinkqubo ekhawulezayo ngokukodwa.

(2) Inkqubo iqulethe i-high-power, i-high-current drive circuit, efana ne-spark generating relay, i-high-current switch, njl.

(3) inkqubo enesiphaluka somqondiso we-analog obuthathaka kunye nokuchaneka okuphezulu kwe-A / D yokuguqulwa kwesiphaluka.

2. La manyathelo alandelayo athatyathiweyo ukwandisa isakhono sokuphazamiseka kwe-anti-electromagnetic interference yesixokelelwano:

(1) Khetha isilawuli esincinci esinefrikhwensi ephantsi:

I-microcontroller enexesha eliphantsi lewotshi yangaphandle inokunciphisa ngokufanelekileyo ingxolo kwaye iphucule amandla okuthintela ukuphazamiseka kwenkqubo. I-square wave kunye ne-sine wave ene-frequency efanayo, icandelo le-frequency ephezulu ye-square wave ingaphezulu kakhulu kune-sine wave. Nangona ukuphakama kwento ephezulu yokujikeleza kwesikwere incinci kunaleyo yentsimbi esisiseko, kokukhona iphindaphindwayo, kokukhona kulula ukukhupha kwaye ube ngumthombo wengxolo. Eyona ngxolo inempembelelo kwisantya esiphezulu esiveliswa yi-microcontroller imalunga namaxesha ama-3 amaxesha ewotshi.

(2) Nciphisa ukuphazamiseka ekuhanjisweni komqondiso

IiMicrocontroller ikakhulu zenziwe ngetekhnoloji ye-CMOS ephezulu. Static input current signal input at about 1 ma, around ten pf in the input capacitance, high input impedance, high speed CMOS circuit outputs are fairly on load capacity, namely the considerable output value, the output end of a door through a very long lead to the high input, the input impedance reflection problem is very serious, it will cause the signal distortion, Yandisa ingxolo yenkqubo. Xa i-Tpd “Tr”, iba yingxaki yomgca wothumelo, kufuneka ithathele ingqalelo ukubonakaliswa kwesignali, ukulinganisa i-impedance kunye nokunye.

Ixesha lokulibaziseka kwesignali kwibhodi eprintiweyo ihambelana ne-impedance yeempawu zokukhokela, oko kukuthi, kwi-dielectric constant of the material board eprinted. Iimpawu zinokucingelwa ukuba zihamba phakathi kwe-1/3 kunye ne-1/2 isantya sokukhanya ngaphezulu kwesikhokelo sePCB. I-Tr (ixesha eliqhelekileyo lokulibaziseka) lezinto zefowuni ze-logic ezisetyenziswa rhoqo kwiinkqubo ezenziwe nge-microcontrollers ziphakathi kwe-3 kunye ne-18ns.

Kwibhodi yesiphaluka eprintiweyo, umqondiso udlula kwi-resistor ye-7W kunye ne-25cm ehamba phambili, kunye nokulibaziseka kwe-intanethi malunga ne-4 ukuya kwi-20ns. That is to say, the signal on the printed line lead as short as possible, the longest should not exceed 25cm. Kwaye inani lemingxuma kufuneka libe lincinci kangangoko kunokwenzeka, lingabi ngaphezu kwe-2.

Xa ixesha lokunyuka komqondiso likhawuleza kunexesha lokulibaziseka komqondiso, kusetyenziswa i-elektroniki ekhawulezayo. Ngeli nqanaba, ukuhambelana kwe-impedance yomgca wothumelo kufuneka kuthathelwe ingqalelo. Ukuhanjiswa komqondiso phakathi kweebhloko ezidibeneyo kwibhodi yesiphaluka eprintiweyo, i-Td Trd kufuneka igwenywe. Inkulu ibhodi yesekethe eprintiweyo, ngokukhawuleza inkqubo ayikwazi ukukhawuleza.