PCB wiring yakakosha mune yese PCB dhizaini. Maitiro ekuwana nekukurumidza uye inoshanda waya uye kuita kuti PCB yako wiring itaridzike kureba yakakodzera kudzidza. Ronga zvinhu zvinomwe zvinoda kutariswa muPCB wiring, uye huya kuzoona zvakasiiwa uye kuzadza zvinzvimbo!

1. Zvakajairika kugadziriswa kwepasi kwedhijitari wedunhu uye dunhu reanalogog

MaPCB mazhinji haachisiri ega-basa maseketi (dhijitari kana analogi maseketi), asi anoumbwa nemusanganiswa wemaseketi edhijitari neanalogi. Nokudaro, zvakakosha kufunga nezvekupindirana pakati pavo kana wiring, kunyanya kupindira kweruzha patambo yepasi. Iyo yakawanda yedhijitari yedhijitari yakakwirira, uye kunzwisiswa kweiyo analog yedunhu yakasimba. Kune mutsara wechiratidzo, iyo yakakwira-frequency siginecha mutsara unofanirwa kunge uri kure sezvinobvira kubva kune inonzwisa analog yedunhu mudziyo. Kune yepasi mutsara, iyo PCB yese ine node imwe chete kune yekunze, saka Dambudziko redhijitari uye analog yakajairika inofanirwa kugadziriswa mukati mePCB, uye iyo yedhijitari pasi uye analogi pasi mukati mebhodhi zvakapatsanurwa chaizvo uye ivo vari. isina kubatana kune mumwe nemumwe, asi pane iyo interface (yakadai semapulagi, nezvimwewo) inobatanidza PCB kune kunze kwenyika. Pane hukama hupfupi pakati pedhijitari pasi uye iyo analog pasi. Ndapota cherechedza kuti pane imwe nzvimbo yekubatanidza. Kune zvakare zvikonzero zvisiri zvakajairika paPCB, iyo inotemerwa nehurongwa hwekugadzira.

2. Mutsara wechiratidzo wakaiswa pamutsara wemagetsi (pasi)

Mu-multi-layer yakadhindwa bhodhi wiring, nokuti hapana waya dzakawanda dzakasara mumutsara wechiratidzo chemutsara usina kuiswa kunze, kuwedzera mamwe mapeji kunokonzera tsvina uye kuwedzera basa rekugadzira, uye mutengo uchawedzera maererano. Kuti ugadzirise kupokana uku, unogona kufunga nezve wiring pamagetsi (pasi) layer. Iyo tambo yesimba inofanirwa kutariswa kutanga, uye pasi pechipiri. Nokuti zvakanakisisa kuchengetedza kuvimbika kwekuumbwa.

3. Kurapa kwekubatanidza makumbo munzvimbo huru conductors

Munzvimbo huru yepasi (magetsi), makumbo ezvikamu zvakajairika akabatanidzwa kwairi. Kurapa kwemakumbo ekubatanidza kunoda kuongororwa zvakakwana. Mukutaura kwekushanda kwemagetsi, zviri nani kubatanidza mapedhi echikamu chemakumbo kune mhangura yemhangura. Kune dzimwe njodzi dzisingadiwe dzakavanzwa muwelding uye kusangana kwezvikamu, senge: ① Welding inoda maheater ane simba guru. ②Zviri nyore kukonzera chaiwo solder majoini. Naizvozvo, zvese zvemagetsi kuita uye zvinodiwa pakuita zvinogadzirwa kuita muchinjika-pattered pads, anonzi heat shields, anowanzozivikanwa se thermal pads (Thermal), kuitira kuti majoini anotengeswa anogona kugadzirwa nekuda kwekunyanya kupisa-chikamu kupisa panguva yekutengesa. Bonde rakaderedzwa zvakanyanya. Kugadziriswa kwesimba (pasi) gumbo re multilayer board rakafanana.

4. Basa re network network mu cabling

Mune akawanda maCAD masisitimu, wiring inotemerwa zvichienderana netiweki system. Iyo grid yakanyanyisa uye nzira yakawedzera, asi danho rakanyanya kudiki, uye huwandu hwe data mumunda hwakakurisa. Izvi zvichave zvisingadzivisiki zvine zvakakwirira zvinodiwa zvekuchengetedza nzvimbo yechishandiso, uye zvakare kumhanya kwekombuta yekombuta-yakavakirwa zvigadzirwa zvemagetsi. Pesvedzero huru. Mamwe makwara haashandi, seaya anogarwa nemapedhi echikamu chemakumbo kana nemakomba ekukwira nemakomba akaiswa. Magetsi mashoma uye mashoma machanera ane simba guru pachiyero chekugovera. Saka panofanira kunge paine inonzwisisika grid system yekutsigira wiring. Chinhambwe chiri pakati pemakumbo ezvimiro zvakajairwa i0.1 inches (2.54 mm), saka hwaro hwegridi system inogaroiswa kuita 0.1 inches (2.54 mm) kana kuverengera kusingasviki 0.1 inches, senge: 0.05 inches, 0.025 inches, 0.02 inches nezvimwe.

5. Kurapa kwekupa simba uye tambo yepasi

Kunyange kana wiring muPCB bhodhi yose yakapedzwa zvakanaka kwazvo, kupindira kunokonzerwa nekufungisisa kusina kunaka kwemagetsi uye tambo yepasi kunoderedza kushanda kwechigadzirwa, uye dzimwe nguva kunyange kukanganisa kubudirira kwechigadzirwa. Nokudaro, iyo wiring yemagetsi uye tambo yepasi inofanira kutorwa zvakakomba, uye kukanganiswa kweruzha kunokonzerwa nemagetsi uye pasi pasi kunofanira kuderedzwa kuti kuve nechokwadi chehutano hwechigadzirwa. Injiniya yega yega inobata mukugadzira zvigadzirwa zvemagetsi inonzwisisa chikonzero cheruzha pakati petambo yepasi uye waya yemagetsi, uye iko zvino chete kuderedzwa kweruzha kunoratidzwa: inozivikanwa kuwedzera ruzha pakati pesimba rekupa uye pasi. waya. Lotus capacitor. Wedzesa hupamhi hwesimba uye waya dzepasi zvakanyanya sezvinobvira, zviri nani waya yepasi yakafara kupfuura waya yemagetsi, hukama hwavo ndehwe: waya yepasi “simba waya” chiratidzo chewaya, kazhinji chiratidzo chewaya upamhi ndeye: 0.2 ~ 0.3mm, iyo yakanakisa hupamhi inogona kusvika 0.05 ～0.07mm, tambo yemagetsi ndeye 1.2 ~ 2.5mm. Kune PCB yedhijitari yedhijitari, waya yakafara yepasi inogona kushandiswa kugadzira loop, ndiko kuti, mambure evhu anogona kushandiswa (pasi redunhu reanalog harigone kushandiswa nenzira iyi). Nzvimbo yakakura yemhangura yemhangura inoshandiswa sewaya yepasi, isingashandiswe pabhodhi rakadhindwa. Yakabatanidzwa pasi sewaya yepasi munzvimbo dzese. Kana kuti inogona kugadzirwa kuita multilayer board, uye magetsi uye waya dzepasi dzinotora imwe layer imwe neimwe.

6. Kuongorora mutemo wekugadzira (DRC)

Mushure mekunge dhizaini yapera, zvinodikanwa kunyatso tarisisa kana iyo wiring dhizaini inoenderana nemitemo yakagadzirwa nemugadziri, uye panguva imwecheteyo, zvinodikanwa kusimbisa kana iyo yakatemerwa mitemo inosangana nezvinodiwa zveyakadhindwa bhodhi kugadzirwa. . Kuongorora kwese kune zvinotevera: mutsetse uye mutsetse, mutsetse Kana chinhambwe chiri pakati pechikamu padhi, mutsetse uye kuburikidza negomba, chikamu padhi uye kuburikidza negomba, uye kuburikidza negomba uye kuburikidza negomba zvinonzwisisika uye kana zvichisangana nezvinodiwa zvekugadzira. Iko hupamhi hwetambo yemagetsi uye mutsara wepasi wakakodzera, uye pane kusungirirwa kwakasimba pakati petambo yemagetsi uye mutsara wepasi (low wave impedance)? Pane chero nzvimbo muPCB umo waya yepasi inogona kukwidziridzwa? Kunyangwe matanho akanakisa akatorwa kune akakosha masaini mitsara, senge ipfupi kureba, mutsara wekudzivirira unowedzerwa, uye mutsara wekupinza uye mutsara wekubuda wakaparadzaniswa zvakajeka. Kunyangwe paine akapatsanurwa pasi waya dzeanalogi sedunhu uye dijitari redunhu. Kunyangwe magiraidhi (akadai sezvidhori uye zvirevo) akawedzerwa kuPCB achakonzera chiratidzo chipfupi chedunhu. Shandura mamwe maumbirwo emitsara asingadiwi. Pane mutsetse wekuita paPCB? Kunyangwe iyo solder mask inosangana nezvinodiwa zvekugadzira maitiro, ingave solder mask size yakakodzera, uye kana iyo logo yemhando yakatsikirirwa padhidhi yemudziyo, kuti isakanganisa kunaka kwemidziyo yemagetsi. Kunyangwe iyo yekunze furemu kumucheto kwesimba repasi pasi mu-multi-layer board yakaderedzwa, kana iyo mhangura yemhangura yesimba repasi pasi yakaburitswa kunze kwebhodhi, zviri nyore kukonzera pfupi pfupi.

7. Kuburikidza nekugadzira

Via ndechimwe chezvinhu zvakakosha zvePCB yakawanda-layer, uye mari yekuchera inowanzoita 30% kusvika 40% yePCB yekugadzira mutengo. Zvichitaurwa zviri nyore, gomba rega rega paPCB rinogona kunzi via. Kubva pakuona kwebasa, vias inogona kukamurwa kuva mapoka maviri: imwe inoshandiswa pakubatanidza magetsi pakati pezvikamu; imwe yacho inoshandiswa kugadzirisa kana kuisa midziyo. Panyaya muitiro, vias kazhinji akakamurwa muzvikamu zvitatu, kureva bofu vias, akavigwa vias uye kuburikidza vias.

Mabofu maburi anowanikwa pamusoro uye pasi pepamusoro pebhodhi redunhu rakadhindwa uye ane humwe hudzamu. Izvo zvinoshandiswa kubatanidza mutsara wepamusoro uye mutsara uri pasi wemukati. Kudzika kwegomba kazhinji hakupfuuri imwe chiyero (aperture). Gomba rakavigwa rinoreva gomba rekubatanidza riri muchikamu chemukati chebhodhi redunhu rakadhindwa, risingapfuuri kumusoro kwebhodhi redunhu. Mhando mbiri dzataurwa pamusoro apa dzemaburi dziri muchikamu chemukati chebhodhi redunhu, uye dzinopedzwa neburi-gomba rekugadzira nzira isati yave lamination, uye akati wandei emukati akaturikidzana anogona kupindirana panguva yekuumbwa kweiyo via. Rudzi rwechitatu runodanwa kuburikidza negomba, iro rinopinda mubhodhi rose redunhu uye rinogona kushandiswa mukati mekubatana kana sechikamu chekuisa chinzvimbo chegomba. Nekuti iyo kuburikidza neburi iri nyore kuona mukuita uye mutengo wakaderera, unoshandiswa mune akawanda akadhindwa edunhu mabhodhi pachinzvimbo chemamwe marudzi maviri epaburi. Zvinotevera nemaburi, kunze kwekunge zvatsanangurwa neimwe nzira, zvinotorwa semaburi.

1. Kubva pane imwe nzvimbo yekuona, via via inonyanya kuumbwa nezvikamu zviviri, imwe igomba rekuchera pakati, uye imwe inzvimbo yepadhi yakakomberedza gomba rekuchera. Saizi yezvikamu zviviri izvi inosarudza saizi yevia. Zviripachena, mune yakakwirira-kumhanya, yakakwirira-density PCB dhizaini, vagadziri vanogara vachitarisira kuti diki kuburikidza negomba, zviri nani, kuitira kuti yakawanda wiring nzvimbo inogona kusiiwa pabhodhi. Mukuwedzera, iyo diki iyo via gomba, iyo parasitic capacitance yayo. Iyo diki iyo, iyo inonyanya kukodzera kune yakakwirira-speed circuits. Zvisinei, kuderedzwa kwegomba kukura kunounzawo kuwedzera kwemutengo, uye saizi yevias haigoni kuderedzwa nekusingaperi. Inodziviswa nehunyanzvi hwekuita senge kuchera uye plating: iyo diki gomba, kuwedzera kuchera Iyo yakareba gomba inotora, zviri nyore kutsauka kubva panzvimbo yepakati; uye kana kudzika kwegomba kuchipfuura 6 nguva yehupamhi hwegomba rakacherwa, haigoni kuvimbiswa kuti rusvingo rwegomba runogona kuiswa zvakafanana nemhangura. Semuyenzaniso, ukobvu (kuburikidza negomba kudzika) kweyakajairwa 6-layer PCB board inenge 50Mil, saka hudiki hwekuchera dhayamita hunogona kupihwa nevagadziri vePCB hunogona kungosvika 8Mil.

Chechipiri, iyo parasitic capacitance ye via hole pachayo ine parasitic capacitance pasi. Kana zvichizivikanwa kuti dhayamita yegomba rekuzviparadzanisa riri pazasi pedhiza iri D2, iyo dhayamita yepadhi iri D1, uye ukobvu hwePCB board ndiT, Iyo dielectric inogara yebhodhi substrate ndeye ε, uye iyo parasitic capacitance yeVia inenge: C = 1.41εTD1 / (D2-D1) Mhedzisiro huru yeparasitic capacitance ye via padunhu ndeyekuwedzera nguva yekusimuka kwechiratidzo uye kuderedza Kukurumidza kwedunhu.

3. Parasitic inductance of vias Saizvozvowo, pane parasitic inductances pamwe parasitic capacitances mu vias. Mukugadzirwa kwepamusoro-kumhanya dhijitari maseketi, kukuvadzwa kunokonzerwa neparasitic inductances ye vias kazhinji kwakakura kupfuura kukanganisa kweparasitic capacitance. Yayo parasitic series inductance inoderedza mupiro weiyo bypass capacitor uye inonetesa kusefa kweiyo yese simba system. Tinogona kungoverenga fungidziro yeparasitic inductance ye via neinotevera fomula: L=5.08h[ln(4h/d)+1] apo L inoreva kudhonzwa kwenzira, h kureba kwenzira, uye d. ndiro pakati The dhayamita yegomba. Iyo inogona kuoneka kubva kuformula kuti dhayamita yeVia ine diki pesvedzero pane inductance, uye kureba kweiyo via kune pesvedzero huru pane inductance.

4. Via dhizaini mune yakakwirira-kumhanya PCB. Kuburikidza pamusoro ongororo pamusoro parasitic unhu vias, tinogona kuona kuti mukuru-nokukurumidza PCB magadzirirwo, sokuti nyore vias kazhinji kuunza zvakaipa zvikuru kuti redunhu magadzirirwo. effect.