Umthamo Wamanje Wokulandelela I-PCB: Ububanzi, Isisindo Sethusi, kanye ne-IPC-2221

Yonke i-trace yethusi iyi-resistor encane efudumalayo lapho ugesi ugeleza kuyo. Yilinganise kahle bese ibhodi lihlala lipholile iminyaka eminingi; uyilinganise ibe mfushane bese i-trace ishisa kakhulu, iguge i-laminate, futhi ingavuleka njenge-fuse. Lo mhlahlandlela uphendula imibuzo onjiniyela abayifuna ngempela - ukuthi i-trace ithwala ama-amps amangaki, ukuthi ithusi elingu-1 oz lingakanani ngamamilimitha, ukuthi kufanele lishintshele nini kuthusi elisindayo - futhi ubonisa ukuthi i-Highleap Electronics iguqula kanjani lezo zinombolo zibe ibhodi engalikhiqiza futhi lihlanganiswe ngokwethembeka.

1. Zingaki ama-amps angathwalwa yi-trace yethusi?

Akukho mandla amakhulu kakhulu okulandela umkhondo – umkhawulo uwukuthi yikuphi ukunyuka kwezinga lokushisa okwamukelayo. Njengereferensi esheshayo, umkhondo ongu-1 mm (cishe amamililitha angu-40) ububanzi kuthusi elingu-1 oz osendlalelo sangaphandle uthwala cishe ama-2 A ekukhuphukeni okungu-10°C okulondolozayo, kanye nama-4 A ekukhuphukeni okungu-30°C. Ugesi ushisa umkhondo ngokulingana nokumelana nesikhathi esiphindwe kabili samanje, futhi umkhondo uhlala noma kuphi lapho ungakhipha khona lokho kushisa kuthusi elizungezile, i-laminate, kanye nomoya.

Izakhiwo ezintathu zokulandelela zibeka ukumelana ngakho-ke ukushisa. Indawo enqamulayo - ububanzi buphindaphinda ubukhulu bethusi - bubusa; buphindwe kabili noma bube yisigamu sokumelana. Ubude bunezela ukumelana okulinganiselayo kanye nokwehla kwamandla kagesi kodwa abushintshi izinga lokushisa eliphakeme kakhulu. Futhi ukumelana kwethusi kukhuphuka cishe ngo-0.4% nge-°C, ngakho-ke umkhondo oshisayo uyindlela yokumelana ephakeme kancane, ebuyela ekushiseni okwengeziwe. Izici ezintathu zemvelo zinquma ukuthi ukushisa kuphuma kalula kangakanani: ungqimba lwangaphandle uma kuqhathaniswa nolwangaphakathi, izinga lokushisa elingaphakathi ngaphakathi kwe-enclosure, kanye nanoma yikuphi ukugeleza komoya noma ukushisa. Uma umusha endleleni yokwakheka nokuchazwa kwezindlela zokulandelela ze-PCB, izisekelo zomklamo wokulandelela we-PCB ziyindlela ewusizo yokuqala ngaphambi kokulinganisa amandla.

2. Kuyini ukujiya kwethusi okungu-1 oz ngo-mm? (ishadi lesisindo sethusi)

Ithusi eliyi-1 oz lingama-microns angu-35 ubukhulu, okungama-0.035 mm noma cishe ama-mil angu-1.37. Ubukhulu bethusi bucashunwa ngesisindo ngefithi lesikwele – indlela endala ekhungathekisa abaqalayo – ngakho ukuguqulwa okufanele ukukhumbule yile:

Ngenxa yokuthi umthamo ulandela indawo enqamula ingxenye, uphatha ugesi omningi ngokwandisa umkhondo noma ngoku-oda ithusi elijiyile. Ebhodini eliqinile, ukukhuphukela ekwakheni ithusi elingu-3 oz kuvame ukuhlanzeka kunokusika isikhala sethrekhi ebanzi kakhulu, futhi ngomsebenzi onamandla amakhulu i -PCB egcwele ithusi elisindayo yakhelwe umsebenzi ngenhloso.

3. Ububanzi be-trace vs ishadi lamanje (ithusi elingu-1 oz kanye nethusi elingu-2 oz)

Ku-1 oz yethusi esendlaleloni sangaphandle ekukhuphukeni okulinganiselwe kwe-10°C, i-trace engu-1 A idinga cishe u-0.5 mm (20 mil) kanye ne-trace engu-3 A cishe u-1.8 mm (70 mil). Ishadi eligcwele elingezansi liyindawo yokuqala esekelwe ku-IPC-2221, hhayi indawo yokubala ngokumelene nethagethi yakho yokushisa; i-trace ye-inside-layer ngokuvamile idinga cishe ububanzi obuphindwe kabili.

Ububanzi bukhula ngokushesha ngogesi. Ngemva kwama-amps ambalwa, umzila owodwa uba yinto engasebenzi, futhi impendulo engcono kakhulu ukuthululwa kwethusi noma iplani yethusi, umzila ohambisanayo ezingqimbeni eziningana ezithungwe ngama-via, noma ithusi elisindayo – okuyilapho ubunjiniyela obunamandla omthamo wamandla ethusi elisindayo bugcina khona imisele yamandla aphezulu ipholile.

4. Ububanzi bomkhondo wangaphakathi nowangaphandle: kungani imikhondo yangaphakathi idinga ukuba banzi

I-trace yangaphakathi idinga cishe ububanzi obuphindwe kabili be-trace yangaphandle ukuze ithwale ugesi ofanayo, ngoba ifakwe ku-laminate futhi ayikwazi ukukhipha ukushisa emoyeni. I-IPC-2221 isebenzisa ama-constant ahlukene kulezi zimo ezimbili ngenxa yalesi sizathu - i-trace yangaphandle iphola ngokudluliselwa emoyeni, kuyilapho i-trace yangaphakathi igqunywa ngokushisa futhi igcina ukushisa okwengeziwe ngobubanzi obufanayo.

Umphumela osebenzayo: ububanzi obuqinisekisile belendlalelo langaphandle bungashisa kakhulu buthule uma inetha elifanayo lihanjiswa kwelendlalelo langaphakathi ebhodini elinezingqimba eziningi. Uma uhambisa amandla phakathi kwezingqimba, usayizi wekhesi lendlalelo langaphakathi, bese usebenzisa ama-vias amaningi ngokufanayo ekushintsheni ngakunye ukuze ushintsho lwendlalelo lungabi yibhodlela elishisayo.