Menene fadin layin?

Bari mu fara da kayan yau da kullun. Menene daidai faɗin faɗin? Me yasa yake da mahimmanci a tantance takamaiman faɗin faɗin? Manufar PCB wayoyi shine haɗa kowane nau’in siginar lantarki (analog, dijital ko iko) daga kumburi zuwa wani.

Wani kumburi na iya zama fil na wani sashi, reshe na babban alama ko jirgin sama, ko kushin fanko ko wurin gwaji don bincike. Ana auna ma’aunin faɗin a mil ko dubban inci. Daidaitattun faɗin wayoyi don sigina na yau da kullun (babu buƙatun musamman) na iya zama inci da yawa a tsawon a cikin mil mil 7-12, amma yakamata a yi la’akari da abubuwa da yawa lokacin da ake bayyana faɗin wayoyi da tsayin su.

Aikace -aikacen yawanci yana motsa faɗin wayoyi da nau’in wayoyi a cikin ƙirar PCB kuma, a wani lokaci, yawanci yana daidaita farashin masana’antar PCB, yawa/girman allo, da aiki. Idan hukumar tana da takamaiman buƙatun ƙira, kamar haɓakawa da sauri, hayaniya ko murƙushe haɗin gwiwa, ko babban halin yanzu/ƙarfin lantarki, faɗin da nau’in alama na iya zama mafi mahimmanci fiye da haɓaka ƙimar ƙirar PCB mara ƙima ko girman girman hukumar.

Ƙayyadewa dangane da wayoyi a cikin masana’antar PCB

Yawanci, waɗannan ƙayyadaddun bayanai masu alaƙa da wayoyi suna fara haɓaka ƙimar kera PCBS mara ƙima.

Dangane da tsauraran haƙƙoƙin PCB da babban kayan aikin da ake buƙata don ƙira, dubawa ko gwajin PCBS, farashi ya yi yawa:

L Faɗin faɗin ƙasa da mil 5 (0.005 in.)

L Trace tazara ƙasa da mil mil 5

L Ta ramuka kasa da mil 8 a diamita

L Trace kauri kasa ko daidai da oza 1 (daidai yake da mil mil 1.4)

L Bambanci daban -daban da tsawon sarrafawa ko hana wayoyi

Tsarin ƙira mai yawa wanda ya haɗu da ɗaukar sararin PCB, kamar BGA mai tazara sosai ko ƙimar siginar siginar a layi daya, na iya buƙatar faɗin layin mil mil 2.5, kazalika da nau’ikan ramuka na musamman tare da diamita har zuwa mil 6, irin wannan kamar yadda Laser ya haƙa microthrough-ramuka. Sabanin haka, wasu ƙirar ƙira mai ƙarfi na iya buƙatar babban wayoyi ko jiragen sama, suna cinye duka yadudduka da zub da oza waɗanda suka fi kauri. A cikin aikace-aikacen da ke taƙaita sararin samaniya, ana iya buƙatar faranti masu bakin ciki waɗanda ke ɗauke da yadudduka da yawa da kaurin jan ƙarfe na rabin oza (kaurin mil 0.7).

A wasu lokuta, ƙira don sadarwa mai sauri daga gefe ɗaya zuwa wani na iya buƙatar wayoyi tare da hana sarrafawa da takamaiman faɗaɗa da tazara tsakanin juna don rage girman tunani da haɗin kai. Ko ƙirar na iya buƙatar wani tsayin don dacewa da wasu sigina masu dacewa a cikin bas. Manyan aikace -aikacen wutar lantarki suna buƙatar wasu fasalulluka na aminci, kamar rage girman tazara tsakanin sigina daban -daban da aka fallasa don hana arcing. Ba tare da la’akari da halaye ko fasali ba, fassarar mahimmancin yana da mahimmanci, don haka bari mu bincika aikace -aikace daban -daban.

Wayoyi iri -iri da kauri

PCBS yawanci yana ƙunshe da faɗin layin iri -iri, saboda sun dogara da buƙatun sigina (duba Hoto 1). Alamar mafi kyau da aka nuna don siginar matakin TTL ce (transistor-transistor logic) kuma ba ta da buƙatu na musamman don babban halin yanzu ko kariyar amo.

Waɗannan za su zama nau’ikan wiring na yau da kullun a kan jirgin.

An inganta wayoyi masu kauri don ƙarfin ɗaukar nauyi na yanzu kuma ana iya amfani da shi don keɓewa ko ayyuka masu alaƙa da wutar lantarki waɗanda ke buƙatar ƙarfi mafi girma, kamar magoya baya, injin, da canja wurin wutar lantarki na yau da kullun zuwa ƙananan matakan. Hagu na hagu na adadi har ma yana nuna siginar banbanci (USB high-speed) wanda ke ayyana takamaiman tazara da faɗi don saduwa da buƙatun rashin ƙarfi na 90 ω. Hoto na 2 yana nuna allon kewaye mai ɗanɗano wanda ke da yadudduka shida kuma yana buƙatar taro na BGA (grid grid array) wanda ke buƙatar mafi ƙarancin wayoyi.

Yadda ake lissafin faɗin layin PCB?

Bari mu bi hanyar aiwatar da lissafin wani faɗin faɗin alama don siginar wutar da ke canja wurin yanzu daga ɓangaren wutar lantarki zuwa naúrar gefe. A cikin wannan misalin, zamu lissafa mafi ƙarancin faɗin layin layin wutar don motar DC. Hanyar wutar tana farawa a cikin fuse, ta ƙetare H-gada (ɓangaren da ake amfani da shi don gudanar da watsa wutar lantarki a cikin iskar motar DC), kuma ta ƙare a mai haɗa motar. Matsakaicin matsakaicin matsakaicin halin yanzu da motar DC ke buƙata shine kusan amperes 2.

Yanzu, wayoyin PCB suna aiki azaman mai tsayayya, kuma mafi tsayi da ƙuntata wayoyi, ana ƙara ƙarin juriya. Idan ba a ayyana wayoyi daidai ba, babban halin yanzu na iya lalata wayoyi da/ko haifar da raguwar ƙarfin lantarki zuwa motar (wanda ke haifar da rage saurin gudu). NetC21_2 da aka nuna a cikin Hoto na 3 ya kai kusan inci 0.8 kuma yana buƙatar ɗaukar matsakaicin halin yanzu na amperes 2. Idan muka ɗauki wasu yanayi na gabaɗaya, kamar 1 oza na zubin tagulla da zafin ɗaki yayin aiki na yau da kullun, muna buƙatar ƙididdige ƙaramin layin layi da raguwar matsin lamba da ake tsammanin a wannan faɗin.

Yadda ake lissafin juriya na PCB?

Ana amfani da lissafin da ke biyowa don gano wuri:

Yanki [Mils ²] = = (na yanzu [Amps] / (K * (Temp_Rise [° C]) ^ b)) ^ (1 / C), wanda ke bi IPC Layer na waje (ko sama / kasa), k = 0.048, b = 0.44, C = 0.725. Lura cewa kawai madaidaicin da muke buƙatar sakawa shine na yanzu.

Amfani da wannan yanki a cikin lissafin da ke gaba zai ba mu faɗin da ake buƙata wanda ke gaya mana faɗin layin da ake buƙata don ɗaukar halin yanzu ba tare da wata matsala ba:

Nisa [Mils] = yanki [Mils ^ 2] / (kauri [oz] * 1.378 [mils / oz]), inda 1.378 ke da alaƙa da daidaiton 1 oz mai kauri.

Ta shigar da amperes 2 na yanzu a cikin lissafin da ke sama, muna samun mafi ƙarancin mil mil 30 na wayoyi.

Amma wannan ba ya gaya mana menene raguwar ƙarfin lantarki zai kasance. Wannan ya fi shiga saboda yana buƙatar lissafin juriya na waya, wanda za a iya yi bisa ga tsarin da aka nuna a cikin Hoto na 4.

A cikin wannan dabarar, ρ = resistivity na jan ƙarfe, α = coefficient na jan ƙarfe, T = alamar kauri, W = faɗin faɗin, L = tsayin tsayi, T = zazzabi. Idan an saka duk ƙimar da ta dace a cikin tsayin 0.8 “na faɗin mil mil 30, za mu ga cewa juriya na wayoyi kusan 0.03 ne? Kuma yana rage ƙarfin lantarki ta kusan 26mV, wanda yayi kyau don wannan aikace -aikacen. Yana da amfani mu san abin da ke shafar waɗannan dabi’u.

Tazarar kebul na PCB da tsayinsa

Don ƙirar dijital tare da sadarwa mai saurin gudu, ana iya buƙatar takamaiman tazara da tsayin tsayin don rage girman sifa, haɗa kai, da tunani. A saboda wannan dalili, wasu aikace-aikacen gama gari sune keɓaɓɓun siginar kebul na USB da siginar bambance-bambancen tushen RAM. Yawanci, USB 2.0 zai buƙaci jujjuyawar banbanci a 480Mbit/s (kebul mai saurin gudu na USB) ko sama. Wannan wani bangare ne saboda kebul mai saurin gudu yawanci yana aiki da ƙananan ƙarfin lantarki da bambance-bambance, yana kawo matakin siginar gabaɗaya kusa da amo na baya.

Akwai muhimman abubuwa guda uku da za a yi la’akari da su yayin tuƙa kebul na USB mai sauri: faɗin waya, tazarar gubar, da tsayin kebul.

Duk waɗannan suna da mahimmanci, amma mafi mahimmanci na ukun shine tabbatar da cewa tsawon layin biyu yayi daidai gwargwado. A matsayin babban yatsan yatsa, idan tsawon igiyoyin sun bambanta da juna ta hanyar da ba ta wuce mil mil 50 (don kebul mai saurin gudu), wannan yana ƙara haɗarin yin tunani, wanda na iya haifar da rashin sadarwa mara kyau. 90 ohm impedance madaidaiciya shine takamaiman bayani don wayoyi biyu daban. Don cimma wannan burin, yakamata a inganta hanyar zirga -zirga a cikin nisa da tazara.

Hoto na 5 yana nuna misalin ma’aurata daban-daban don keɓaɓɓun keɓaɓɓun kebul na USB waɗanda ke ɗauke da madaidaitan mil 12 a cikin tazarar mil 15.

Ƙarfafawa don abubuwan da ke tushen ƙwaƙwalwar ajiya waɗanda ke ɗauke da musaya masu kama da juna (kamar DDR3-SDRAM) za su fi ƙuntatawa dangane da tsawon waya. Yawancin software na ƙirar PCB mafi girma za su sami damar daidaita tsayin tsayi wanda ke haɓaka tsayin layin don dacewa da duk siginar da ta dace a cikin bas ɗin. Hoto na 6 yana nuna misalin ƙirar DDR3 tare da wayoyin daidaitawa.

Burbushi da jirage na cika ƙasa

Wasu aikace-aikace tare da abubuwan da ke tattare da hayaniya, kamar kwakwalwan kwamfuta mara waya ko eriya, na iya buƙatar ƙarin kariya kaɗan. Zayyana wayoyi da jirage tare da ramuka na ƙasa da aka haɗa na iya taimakawa ƙwarai rage haɗe-haɗe na wayoyin da ke kusa ko ɗaukar jirgin sama da siginar jirgin da ke rarrafe zuwa gefunan jirgin.

Hoto na 7 yana nuna misalin tsarin Bluetooth wanda aka sanya kusa da gefen farantin, tare da eriyarsa (ta allon da aka buga alamar “ANT”) a waje da layin mai kauri wanda ke kunshe da ramukan da aka haɗa da tsarin ƙasa. Wannan yana taimakawa ware eriya daga sauran hanyoyin jirgi da jirage.

Za’a iya amfani da wannan madadin hanyar juyawa ta cikin ƙasa (a wannan yanayin jirgin polygonal) don kare da’irar jirgi daga siginar mara waya ta waje. Hoto na 8 yana nuna PCB mai hayaniyar amo tare da jirgin da aka saka a cikin rami tare da gefen jirgin.

Mafi kyawun ayyuka don wayoyin PCB

Abubuwa da yawa suna tantance halayen wayoyi na filin PCB, don haka tabbatar da bin mafi kyawun ayyuka lokacin haɗa PCB na gaba, kuma za ku sami daidaituwa tsakanin ƙimar PCB fab, yawa kewaye, da kuma aikin gaba ɗaya.