PCB bolodi vuto lalifupi lozungulira

Choyambitsa chachikulu cha PCB yaying’ono ndi mapangidwe osayenera a pad. Panthawiyi, pad yozungulira ikhoza kusinthidwa kukhala mawonekedwe a elliptical kuti awonjezere mtunda pakati pa mfundo, kuti ateteze maulendo afupikitsa.

Kukonzekera kosayenera kwa zigawo za bolodi za PCB kudzachititsanso kuti chigawo chachifupi cha bolodi la dera chisagwire ntchito. Ngati pini ya SOIC ikufanana ndi mafunde a malata, ndizosavuta kuyambitsa ngozi yayifupi. Pankhaniyi, mayendedwe a gawolo amatha kusinthidwa kukhala perpendicular to mafunde a malata.

Chifukwa china ndi chakuti bolodi la PCB ndi lalifupi-circuited, ndiko kuti, basi pulagi-mu unit ndi akupindika. Monga IPC imanena kuti kutalika kwa waya ndi osachepera 2mm, pamene mbali yopindika ndi yaikulu kwambiri, gawolo ndi lalikulu kwambiri ndipo n’zosavuta kuyambitsa dera lalifupi. Cholumikizira cha solder ndi choposa 2mm kutali ndi dera.

Kuwonjezera pazifukwa zitatu pamwamba, pali zifukwa zina zimene zingachititse yochepa dera zolephera pa bolodi PCB. Mwachitsanzo, dzenje la gawo lapansi ndi lalikulu kwambiri, kutentha kwa ng’anjo ya malata ndikotsika kwambiri, kusungunuka kwa bolodi kumakhala koyipa, chigoba cha solder ndi chopanda pake, ndi bolodi. Kuwonongeka kwapamtunda ndi zina ndizomwe zimayambitsa kulephera. Wopangayo amatha kuchotsa ndikuyang’ana zomwe zili pamwambazi ndi zolakwika chimodzi ndi chimodzi.

Njira 4 zosinthira PCB yokhazikika yokhazikika

Kupititsa patsogolo kwafupipafupi kwafupipafupi kwafupipafupi kwa PCB kumachitika makamaka chifukwa cha mikwingwirima pa mzere wopangira mafilimu kapena kutsekeka kwa zinyalala pazenera zokutira. Chophimba chotsutsana ndi plating chimawululidwa ndi mkuwa ndipo chimayambitsa kagawo kakang’ono mu PCB. Zowonjezera ndi izi:

Firimu pafilimuyi sayenera kukhala ndi mavuto monga trachoma, zokopa, ndi zina zotero. Akayika, pamwamba pa filimuyo ayenera kuyang’ana mmwamba ndipo sayenera kupukuta ndi zinthu zina. Pokopera filimuyo, filimuyo imayang’ana pamwamba pa filimuyo, ndipo filimu yoyenera imayikidwa mu nthawi. Sungani mu thumba la filimu.

Pamene filimu ikuyang’ana, ikuyang’anizana ndi PCB pamwamba. Pojambula filimu, nyamulani diagonal ndi manja onse awiri. Osakhudza zinthu zina kuti mupewe kukanda pamwamba pa filimuyo. Mbale ikafika pa nambala inayake, filimu iliyonse iyenera kusiya kugwirizanitsa. Chongani kapena kusintha pamanja. Ikani mu thumba loyenera la filimu ndikulisunga.

Oyendetsa sayenera kuvala zokongoletsera zilizonse, monga mphete, zibangili, ndi zina zotero. Misomali iyenera kudulidwa ndikusungidwa m’munda. Palibe zinyalala zomwe ziyenera kuikidwa pamwamba pa tebulo, ndipo pamwamba patebulo payenera kukhala yoyera komanso yosalala.

Pamaso kupanga chophimba Baibulo, ayenera mosamalitsa kufufuzidwa kuonetsetsa kuti palibe mavuto. Mtundu wazenera. Mukamagwiritsa ntchito filimu yonyowa, nthawi zambiri zimakhala zofunikira kuyang’ana pepala kuti muwone ngati pali kupanikizana kwa pepala pawindo. Ngati palibe kusindikiza kwakanthawi, muyenera kusindikiza chinsalu chopanda kanthu kangapo musanasindikize kuti chocheperako mu inki chithe kusungunula inki yolimba kuti chitseko chitseguke bwino.

PCB board yochepa yoyendera njira

Ngati ndi kuwotcherera pamanja, ndikofunikira kukhala ndi zizolowezi zabwino. Choyamba, yang’anani bolodi la PCB musanayambe kugulitsa, ndipo gwiritsani ntchito multimeter kuti muwone ngati mabwalo ovuta (makamaka magetsi ndi nthaka) ndi ofupikitsidwa. Kachiwiri, gulitsani chip nthawi zonse. Gwiritsani ntchito ma multimeter kuti muyese ngati magetsi ndi nthaka ndizofupikitsidwa. Kuonjezera apo, musagulitse chitsulo pamene mukugulitsa. Ngati solder imagulitsidwa kumapazi a solder a chip (makamaka zigawo zokwera pamwamba), sizovuta kupeza.

Tsegulani PCB pakompyuta, yanikirani ma netiweki afupipafupi, ndiyeno muwone ngati ili pafupi kwambiri ndi chosavuta kulumikiza. Chonde tcherani khutu kufupipafupi kwapakati pa IC.

Dera lalifupi linapezedwa. Tengani bolodi kuti mudule mzere (makamaka gulu limodzi/lawiri). Pambuyo podula, gawo lililonse la chipikacho limapatsidwa mphamvu padera, ndipo mbali zina siziphatikizidwa.

Gwiritsani ntchito makina osanthula malo aafupi, monga: Singapore PROTEQ CB2000 short-circuit tracker, Hong Kong Ganoderma QT50 short-circuit tracker, British POLAR ToneOhm950 multilayer board short-circuit detector.

Ngati pali chipangizo cha BGA, popeza zida zonse za solder sizikuphimbidwa ndi chip, ndipo ndi bolodi lamitundu yambiri (zoposa 4 zigawo), ndi bwino kugwiritsa ntchito mikanda ya maginito kapena 0 ohm kuti mulekanitse mphamvu ya aliyense. chip mu kapangidwe. Chotsutsacho chimalumikizidwa kotero kuti mphamvu ikadutsa pang’onopang’ono pansi, mikanda ya maginito imadziwika ndipo zimakhala zosavuta kupeza chip china. Chifukwa BGA ndizovuta kugulitsa, ngati sizikuwotchera makina, mphamvu zoyandikana ndi mipira ya solder pansi idzafupikitsidwa mosamala.

Samalani pamene ma soldering maola-akuluakulu ndi ang’onoang’ono okwera pamwamba, makamaka ma capacitor amagetsi (103 kapena 104), amatha kuyambitsa dera lalifupi pakati pa magetsi ndi pansi. Inde, nthawi zina ndi tsoka, capacitor yokha idzakhala yochepa, choncho njira yabwino ndiyo kuyang’ana capacitor musanayambe soldering.