Halogens mu polychlorinated bipheny

Mukafunsa opanga ambiri komwe zinthu za halogen mu a PCB zapezeka, n’zokayikitsa akadakuuzani. Ma halojeni amapezeka kawirikawiri mu brominated flame retardants (BFR), chlorinated solvents ndi polyvinyl chloride (PVC). Ma halojeni sali owopsa mwanjira iliyonse kapena kukhazikika, ndipo palibe mavuto azaumoyo pokhala ndi mapaipi a PVC kapena kumwa madzi apampopi. Mukadawotcha chubu ija ndikupumira mpweya wa chlorine womwe umatulutsidwa pulasitiki ikatha, ikhoza kukhala nkhani ina. Ili ndiye vuto lalikulu ndi ma halojeni mumagetsi. Atha kusindikizidwa kumapeto kwa moyo wa PCB. Chifukwa chake, mumapeza kuti ma halogen mozungulira mu board?

Monga mukudziwa, PVC siyigwiritsidwa ntchito kupopera kokha, komanso kutchingira waya, chifukwa chake ikhoza kukhala gwero la ma halojeni. Zosungunulira za chlorinated zitha kugwiritsidwa ntchito kuyeretsa PCBS panthawi yopanga. BFR imagwiritsidwa ntchito pa PCB laminates kuti achepetse chiopsezo chamoto. Tsopano popeza tafufuza gwero lalikulu la ma halogen mu dera, tiyenera kuchita chiyani?

Halogen yaulere PCB

Monga zofunikira zopanda kutsogola za RoHS, miyezo yaulere ya halogen imafuna kuti CM igwiritse ntchito zida zatsopano ndi njira zopangira. Monga malire aliwonse “opanda halogen” okhazikitsidwa ndi mabungwe osiyanasiyana. Kutanthauzira kwa IEC kwa ma halojeni kulibe chlorine ndi bromine yochepera 900 PPM ndi ma halojeni okwana osakwana 1500 PPM, pomwe RoHS ili ndi malire ake.

Tsopano bwanji mukubwereza “opanda halogen”? Izi ndichifukwa choti kukwaniritsa miyezo sikutanthauza kuti gulu lanu lilibe halogen. Mwachitsanzo, IPC imayang’anira mayeso ozindikira ma halogen mu PCBS, omwe nthawi zambiri amazindikira ma halogen omangidwa ndi ionic. Komabe, ma halogen ambiri omwe amapezeka mu flux amakhala omangika, kotero mayeso sangathe kuwazindikira. Izi zikutanthauza kuti kuti mupange pepala lopanda halogen, muyenera kupitilira zofunikira.

Ngati mukuyang’ana gwero linalake la ma halogens, imodzi ndi TBBPA, yomwe ndi BFR yomwe imagwiritsidwa ntchito kwambiri pamagetsi. Kuchotsa poyambira, muyenera mwachindunji halogen wopanda laminates, monga yogwira phosphorous m’munsi laminates. Flux yanu ndi solder zitha kubweretsanso ma halogen mu PCB, ndiye muyenera kukambirana ndi CM njira zina zomwe zingakhalepo pamenepo. Zingakhale zopweteka kugwiritsa ntchito zida zatsopano ndi matekinoloje pamatabwa, koma ma circuits opanda halogen ali ndi maubwino ena. PCBS yopanda ma halogen nthawi zambiri imakhala yodalirika yoziziritsa kutentha, zomwe zikutanthauza kuti ndiyoyenererana ndi njira zotentha kwambiri zomwe zimafunikira mabwalo opanda lead. Amakhalanso ndi chilolezo chochepa ngati mukufuna kusunga kukhulupirika kwa chizindikiro.

Mapangidwe opanda bolodi a Halogen

Ubwino wa matabwa opanda halogen umabwera pamtengo wowonjezereka wovuta osati pakupanga kokha komanso pakupanga. Chitsanzo chabwino ndi ogulitsa opanda halogen komanso ma fluxes. Mitundu yopanda halogen nthawi zina imatha kusintha kuchuluka kwa solder kukhala flux ndikuyambitsa zokala. Apa ndipamene solder imaphatikizana kukhala mpira waukulu m’malo mogawidwa molumikizana. Njira imodzi yothetsera vutoli ndikutanthauzira bwino pedi ndi filimu yotchinga. Izi zidzakulitsa phala la solder ndikuchepetsa zolakwika.

Zida zambiri zatsopano zili ndi mapangidwe awoawo, ndipo mungafunike kulumikizana ndi wopanga kapena kuchita kafukufuku musanagwiritse ntchito. Mabungwe opanda ma Halogen akukwera, koma osati konsekonse. Muyeneranso kulankhula ndi CM yanu kuti muwone ngati ali ndi kuthekera kopanga PCBS kuchokera ku zida zaulere za halogen.

M’kupita kwa nthawi, timawoneka kuti zinthu zambiri zomwe timagwiritsa ntchito tsiku lililonse zimaika pachiwopsezo paumoyo wathu. Ichi ndichifukwa chake mabungwe ngati IEC amapanga miyezo yama board yopanda ma halogen. Kumbukirani kumene ma halogen amapezeka (BFR, zosungunulira, ndi zosungunulira), kotero ngati mukufuna ma halogen opanda halogen, mukudziwa ma halogen omwe mungalowe m’malo. Miyezo yosiyanasiyana imalola ma halojeni osiyanasiyana, ndipo mitundu ina ya ma halojeni itha kupezeka kapena mwina sichingapezeke. Muyenera kuchita kafukufuku pasadakhale kuti mumvetsetse komwe kuli mavuto pama PCB. Mukadziwa zomwe mungagwiritse ntchito, ndibwino kuti mufunsane ndi wopanga ndi CM kuti mudziwe njira yabwino yopitira patsogolo. Mungafunike kusintha kapangidwe kake kapena kugwira ntchito ndi CM panjira zina zopangira kuti muwonetsetse kuti bolodi lanu limalizidwa bwino.