Comprehensive Guide Kudzivirira PCB Corrosion

PCBs zvinhu zvakakosha mumagetsi emazuva ano, zvinopa musana wekubatanidza uye kutsigira zvinhu zvemagetsi mumidziyo yakasiyana. Nekudaro, ngura injodzi huru kune PCBs, zvinogona kutungamira mukusashanda kana kutadza. Kunzwisisa zvinokonzeresa uye nzira dzekudzivirira dzePCB corrosion kwakakosha kuchengetedza hupenyu hurefu hwechishandiso uye kushanda. Gwaro iri rinoongorora zvinokonzeresa, mhando, nzira dzekuchenesa, uye matanho ekudzivirira edunhu recorrosion, ichipa ruzivo rwakakosha kune nyanzvi dzemagetsi.

Kunzwisisa PCB Corrosion

Corrosion inzira yeoxidation apo oxygen inobatana nesimbi, ichikonzera ngura uye kuora. Tichifunga kuti maPCB ane simbi yakawanda uye anoratidzwa neokisijeni, anogona kutapukirwa nekufamba kwenguva.

Metals uye Corrosion Resistance

Simbi dzinoshandiswa muPCB dzinosiyana mukuramba kukora. Mamwe masimbi anoshingirira zvakanyanya, asi mamwe ari nyore kuita ngura. Heino rondedzero:

Noble Metals (Yakanyanya Kuramba)

• Graphite
• goridhe
• sirivha
• Copper-nickel alloy

Base Metals (Yakanyanya Kubatwa)

• Plated tin
• Tungamira
• mhangura
• Nickel yakarongedzwa

Mhando dzePCB Corrosion: Detailed Analysis uye Solutions

Kunzwisisa marudzi akasiyana ekuora anogona kukanganisa Madhindindi Edunhu Mabhodhi (PCBs) kwakakosha pakudzivirira, kuchengetedza, uye kuvimbika kwenguva refu kwemidziyo yemagetsi. Pazasi, isu tinonyura mune dzakasiyana siyana dzedunhu bhodhi corrosion, zvikonzero zvadzo, zvazvinoreva, uye nzira dzekudzikisa.

Atmospheric Corrosion

Atmospheric corrosion inoitika apo simbi inotarisana nePCB inofumurwa nehunyoro ine okisijeni, zvichitungamira pakuumbwa kwesimbi oxides, kunyanya pamhangura. Mhando iyi yekuora inowedzerwa nekusvibisa kwezvakatipoteredza senge sulfur dioxide (SO₂) uye chlorine, iyo inogona kugadzira maasidhi kana yasangana nehunyoro, ichiwedzera kukurumidza kuita oxidation. Corroded mhangura inorasikirwa zvakanyanya nemagetsi ayo, inokanganisa kutendeseka kwechiratidzo uye kuita kwese kwechishandiso. Mazano ekuderedza anosanganisira:

• Environmental Control: Kushandisa humidity uye tembiricha zvidzore mukugadzira nekuchengetedza nzvimbo kuchengetedza mamiriro akakwana.
• Dziviriro Coatings: Kuisa conformal coatings senge acrylics, polyurethanes, kana parylene, izvo zvinopa chipingamupinyi pakunyorova uye zvinosvibisa. Kushandisa corrosion-resistant surface inopedza seImmersion Silver (ImAg), Electroless Nickel Immersion Gold (ENIG), kana Organic Solderability Preservatives (OSP) kuchengetedza mhangura yakafumurwa.
• Regulant Maintenance: Kuita ongororo nguva nenguva uye kuchenesa uchishandisa isopropyl doro kana nyanzvi PCB yekuchenesa kubvisa chero marara angave akaunganidzwa nekufamba kwenguva.

Galvanic Corrosion

Galvanic corrosion inoitika apo simbi mbiri dzakasiyana dziri mumagetsi emagetsi pamberi pe electrolyte, ichigadzira galvanic cell. Izvi zvinoita kuti iyo inodic simbi (yakaderera) iparare pamwero wekukurumidza, nepo cathodic simbi (yakanyanya kunaka) inoramba yakachengetedzwa. Semuyenzaniso, kana macontacts akapfekwa negoridhe ari padhuze nemajoini ane tin-lead solder, tin-lead alloy inoora nekukurumidza nekuda kwehunhu hwayo hunodic kana ichienzaniswa negoridhe. Nzira dzakakosha dzekudzivirira galvanic corrosion dzinosanganisira:

• Kusarudzwa Kwezvinhu: Kusarudza simbi dzine zvakafanana galvanic zvinogona kuderedza zvingangosiyana kusiyana. Semuenzaniso, kushandisa nickel pachinzvimbo cherata pamwe chete negoridhe.
• Barrier Layers: Kuisa dielectric coatings kana kushandisa insulating zvinhu senge polyimide mafirimu kudzivirira kunanga simbi-kune-simbi kubata.
• Dhizaini Yekugadzirisa: Kuve nechokwadi chekuyerera kwakaringana uye kudzivirira mitsetse iyo electrolytes inogona kuungana, nekudaro kuderedza kuumbwa kwemasero egalvanic. Kushandisa nzira dzekugadzira dzakadai sepamatendi kuvhara mhangura yakashama.

Electrolytic Corrosion

Electrolytic corrosion, inozivikanwawo se dendritic kukura, inosanganisira kugadzirwa kwe conductive simbi filaments (dendrites) pakati pedyo nePCB traces nekuda kwekuvapo kweionic zvinosvibisa uye hunyoro. Iyi nzira inogona kufambiswa ne bias voltages inoiswa pamatehwe, zvichiita kuti maion simbi (eg, sirivheri, copper) ifambe uye igadzire mabhiriji anotungamira kune mapfupi maseketi. Matanho ekudzivirira anosanganisira:

• Yakachena Manufacturing Matanho: Kuve nechokwadi chehutsanana hwakasimba panguva yePCB yekugadzira kubvisa zvinosvibisa ionic. Izvi zvinosanganisira kushandisa deionized mvura yekusuka uye kuchengetedza nzvimbo yakachena yekamuri.
• Enhanced Kuchenesa: Kuita zvakakwana post-assembly yekuchenesa maitiro uchishandisa ultrasonic cleaners uye nyanzvi yekubvisa flux kubvisa chero yakasara flux uye zvimwe zvinosvibisa.
• Conformal Coating: Kuisa conformal coatings sesilicone, epoxy, kana urethane kugadzira chinodzivirira kubva mukunyorova ingress uye ionic kusvibiswa. Kushandisa machira akakora kana akawanda akaturikidzana mune yakakwirira-density interconnect (HDI) PCBs.

Fretting Corrosion

Fretting corrosion inoitika nekuda kwekudzokororwa micro-kufamba pakati pekusangana kwenzvimbo, senge solder-plated switch kana chinongedzo chekubatanidza. Kufamba uku kunobvisa zvidziviriro zveokisijeni, zvichiburitsa simbi iri pasi kukuvadzwa kweoxidative. Nokufamba kwenguva, izvi zvinogona kutungamirira mukuumbwa kweasina-conductive oxides, kuwedzera kupikisa kurambana, uye pakupedzisira kukundikana kwema mechanical switches uye connectors. Kuti udzikise corrosion:

• Kushandiswa Kwemafuta: Kuisa anti-corrosive lubricant, senge conductive girisi kana oiri, kuderedza kukweshera uye kupera. Mafuta aya anopawo chigadziko chekudzivirira kubva kune oxidation.
• Kuomesa zvinhu: Kushandisa zvinhu zvakaomarara kana kurapwa pamusoro, senge electroplating nesimbi dzakaoma segoridhe kana palladium, kuwedzera kuramba kupfeka uye kuderedza kushushikana.
• Madhizaini Magadzirirwo: Kudzikisira kufamba kwehukama mudhizaini nekushandisa yakachengeteka mechani yekumisikidza uye kuve nechokwadi chakasimba chekukwirana kutenderera. Kuita zvinoenderana nepini dhizaini kutora vibrations uye kuderedza micro-kufamba.

Kana chinodiwa ichi chichikanganisa kuwanikwa kana kuburitswa kwezvigadzirwa, chienzanise nekugadzirwa kwePCB yealuminium uye kugadzirwa kwePCB yelaminate ine low-loss usati watumira mafaira ekupedzisira kuti aongororwe.

Kuchenesa Corroded PCBs

Kana PCB ikaita ngura, kuichenesa kunogona kudzorera kushanda kwayo. Kuita uku kunoda zvinhu zvemumba zvakakosha uye kunzwisisa kwakakosha kwemagetsi kudzivirira kukuvadza bhodhi.

Zvinhu Zvinodiwa

• Soda yekubikisa: Inoshanda kune neutralizing corrosion nekuda kwe alkalinity uye abrasiveness.
• Deionized mvura: Inodzivirira imwe kukuvara nekuda kwekushaikwa kwayo kwemaion.
• Muchenesi wepamba: A phosphate-isina cleaner yakanakira kubvisa tsvina uye ngura.
• Soft-bristle brush: Bhuroshi remazino kana bhurashi repende rinoshanda zvakanaka pakukwesha zvinhu zvakapfava.
• Lint-free tauro: Microfiber kana mamwe machira asina-lint anoomesa bhodhi pasina kusiya zvimedu.
• Hovhoni: Inoshandiswa kuomesa PCB nekupisa kusina kunanga.

Kuchenesa Matanho

1. Rekodha iyo PCB's Layout: Tora manotsi akadzama kana mapikicha ekugadzirisa kwakakodzera.
2. Bvisa PCB: Kuparadzanisa bhodhi kubva kune tambo uye machipisi kuti unyatsocheneswa.
3. Shandisa Baking Soda Paste: Sakanidza kubika soda nemvura yakasvibiswa kuti uite paste. Geza nzvimbo dzine ngura nebhurasho uye bvumira kuti bhodhi riome risati rasuka.
4. Shandisa Muchenesa Mumba: Mwaya nzvimbo dzine ngura nemuchenesi, korobha zvakare, woomesa.
5. Dry muovheni: Preheat oven kusvika 170 ° F, bvisa, uye isa PCB mukati kuti iome.
6. Resemble uye Test: Unganidzazve bhodhi uye edza kushanda kwayo. Shandisa eraser kubvisa chero ngura yasara kana zvichidikanwa.

Kudzivirira PCB Corrosion

Kudzivirira corrosion kwakakosha pakuwedzera hupenyu hwePCBs. Kunyangwe zvisingaite kudzivirira ngura zvachose, mamwe matanho anogona kunonoka zvakanyanya.

Makiyi Ekudzivirira Matanho

• Dzivisa Ionic Kusvibiswa: Chengetedza maPCB nezvikamu zvawo zvakachena uye zvakaoma kudzivirira kuratidzwa kune ionic mwando.
• Manufacturing Maitiro: Vagadziri vanofanirwa kudzivirira zvigunwe kana zvinwiwa paPCB uye vogadzira munzvimbo dzakadzorwa.
• Kufunga Kwekugadzira: Dzivirira kuwanda kwehunyoro pamakondukita akafumurwa, kunyanya munzvimbo dzinowanzoita kuratidzwa kwemvura.

Mamwe Matanho Ekudzivirira

• Conformal Coating: Kuisa chivharo chekudzivirira chinodzivirira PCBs kubva kune zvakatipoteredza zvinosvibisa.
• Encapsulation: Kuisa maPCB mumidziyo yekudzivirira kunopa imwe dziviriro kubva kune hunyoro uye corrosive agents.
• Environmental Controls: Chengetedza nzvimbo dzakadzorwa panguva yekugadzira nekuchengetedza PCB kuti uderedze njodzi dzekuora.

mhedziso

Kunzwisisa uye kuderedza PCB corrosion kwakakosha pakuita kuti hupenyu hurefu uye kuvimbika kwemidziyo yemagetsi. Kuita matanho ekudzivirira epamusoro akadai sekutonga kwezvakatipoteredza, machira ekudzivirira, kusarudzwa kwezvinhu, uye kuchengetedza hutsanana hwakaomarara panguva yekugadzira kunogona kuderedza zvakanyanya njodzi yekutadza kunoenderana nekuora. Kugara uchigadzirisa, kuongorora nguva nenguva, uye kutora akanakisa dhizaini maitiro anowedzera kuve nechokwadi chekuita kwakasimba kwePCBs pasi pemamiriro akasiyana ekushanda. Nekugadzirisa matambudziko aya neruzivo rwehunyanzvi uye matekiniki, kuvimbika uye kushanda kwemidziyo yemagetsi kunogona kuchengetedzwa kwehupenyu hwakareba.