Nzvimbo Yokunyungudutsa Yekunyungudutsa: Gwaro Rekupisa kweAlloy

Nzvimbo yekunyunguduka kwe solder inoenderana zvachose ne alloy yayo. Eutectic tin-lead solder (Sn63/Pb37) inonyunguduka pa 183 °C imwe chete, yakapinza (361 °F) , nepo SAC305 inonyanya kunyunguduka pa 217–220 °C (423–428 °F) . Mumhuri yese ye soldering alloys nhamba dzinotangira pa 138 °C ye tin-bismuth ine tembiricha yakaderera kusvika 300 °C zvichikwira kune high-lead solders. Gwaro iri rinopa nhamba chaiyo ye alloy yega yega, rinotsanangura musiyano uripo pakati pe melting point ne melting range, uye rinoratidza kuti nei madhigirii mashoma iwayo achisarudza kana PCB joint yakanaka kana kuti isina kunaka.

Chii chinonzi melting point ye solder?

Nzvimbo yekunyunguduka ndiyo tembiricha iyo solder alloy inoshanduka kubva pakuva yakasimba kuenda kune mvura kuitira kuti inyorovese pamusoro pesimbi yogadzira jointi. Dambudziko nderekuti eutectic alloys chete ndiyo ine nzvimbo imwe chete yekunyunguduka. Musanganiswa we eutectic — Sn63/Pb37 ndiwo muenzaniso wekare — unonyunguduka wooma nechando patembiricha imwe chete isina hunyoro pakati. Kuchinja uku kwakakomba ndosaka eutectic solder ichigadzira majointi akachena uye inokanganwira kushanda nayo.

Mazhinji ma alloys asiri eutectic panzvimbo pezvo anonyunguduka padanho rakaganhurirwa nekupisa kuviri:

• Solidus — tembiricha iyo alloy inotanga kuti inyungudike. Pasi payo inenge yakasimba zvakakwana.
• Liquidus — tembiricha iyo alloy iri zvakazara Pamusoro payo inoyerera zvakasununguka.

Pakati pe solidus ne liquidus, solder inenge yakasimba zvishoma uye imwe inenge iri mvura - iri slushy "pasty" kana "plastic". Majoini akakanganiswa ari mu range iyoyo anowanzobuda asina kusimba uye asina simba (chinowanzokonzera kukanganiswa kana kutonhora kwejoin), ndicho chimwe chikonzero nei eutectic alloys dzisina plastic range dzichinyanya kufarirwa pakusonesa nemaoko.

Nzvimbo yekunyunguduka kwe solder ine lead (tin-lead)

Muchina weTin-lead (SnPb) solder waishandiswa zvakanyanya mumagetsi kwemakumi emakore uye uchiri kushandiswa mumabasa emuchadenga, ekudzivirira, uye ekurapa uko kuvimbika kwawo uye kusavapo kwetsvina dzetin kunokosha. Maitiro ayo ekunyunguduka anoenderana nehuwandu hwetin-to-lead, uye ese maSnPb alloys ane 183 °C solidus (tembiricha ye eutectic):

Chinhu chinobatsira ndechekuti Sn63/Pb37 ndiyo alloy yekusarudza kana uchida majoini akachena zvakanyanya, nekuti haipfuure huwandu hwepasty hunopfuura nemamwe ma ratios.

Nzvimbo inonyunguduka yekunyungudutsa isina mutobvu

RoHS nemitemo yakafanana yakaita seizvi yakasunda maelektroni mazhinji ekutengeserana kuti ashandise solder isina mutobvu, iyo inonyanya kuvakirwa patini ine sirivha, mhangura, uye dzimwe nguva bismuth kana nickel. Ma alloys asina mutobvu anonyunguduka 30–45 °C kupisa kupfuura tin-lead, inova ndiyo mhedzisiro huru yeswitch - inokwidza tembiricha yepamusoro uye kushushikana kwekupisa pamabhodhi nezvikamu.

SAC305 ndiyo inonyanya kushandiswa kugadzira PCB isina mutobvu. Pane mhando dzesirivha yakaderera uye dzakasanganiswa nedoped dzinobatsira kuderedza mutengo kana kuvandudza mashandiro e drop-shock uye thermal-cycling, asi nzvimbo dzadzo dzekunyunguduka dzinogara dziri pedyo ne217 °C SAC nharaunda.

Zvishongedzo zvinopisa zvishoma uye zvinopisa zvakanyanya

Kupfuura maalloys makuru, mapoka maviri ehunyanzvi ari padanho repamusoro rekupisa.

Zvishongedzo zvekupisa zvishoma

Tin-bismuth (Sn42/Bi58) inonyunguduka pa138 °C (281 °F) chete , uye indium-tin (In52/Sn48) pa118 °C (244 °F) . Izvi zvinoshandiswa kana zvikamu kana substrates dzisingakwanise kushivirira kupisa kwakajairwa — ma LED anonzwa kupisa, mamwe ma sensor, substrates dzinochinjika, uye step-soldering apo chikamu chechipiri chinofanira kugadzirwa pasina kunyungudutsa chekutanga. Chinhu chakanaka ndechekuti bismuth alloys dzinowanzova dzakapfava.

Zvishongedzo zvinopisa zvakanyanya

Zvishandiso zvine lead-lead zvakaita seSn10/Pb88/Ag2 (inenge 268–290 °C) uye Sn5/Pb95 (inenge 308–312 °C) zvinoramba zvakasimba patembiricha inonyungudutsa solder yakajairika. Zvinoshandiswa mukati memagetsi e semiconductor die attach, mumagetsi emafuta negesi ari pasi pegomba, uye mune dzimwe nzvimbo dzinopisa. Kuti tiwane ruzivo, pure tin inonyunguduka pa232 °C uye pure lead pa327 °C.

Chati yekufananidza nzvimbo yekunyunguduka kweSolder

Chati iyi yakabatanidzwa inoisa ma alloys akajairika padivi nepadivi, kubva panzvimbo yakaderera yekunyunguduka kusvika pakakwirira.

Nzvimbo yekunyunguduka vs tembiricha yekunyungudutsa uye tembiricha yekuyererazve

Chinhu chinowanzo vhiringidza ndechekuona tembiricha yekunyunguduka kwesimbi kana ovheni yako sekupisa kwaunoisa paaroni yako. Hazvina kudaro. Kunyunguduka kwesimbi kunokuudza kana solder yava mvura; kuti unyorovese mapedhi uye ifambe zvakanaka, unoshanda zvakanyanya kupfuura mvura.

• Tembiricha yemuromo wesimbi inosungirirwa inoiswa pamusoro penzvimbo inonyunguduka kuti ipinde mujoini nekukurumidza muromo usati watonhora. Maitiro akajairika anenge ari pamusoro penzvimbo inonyunguduka. 315–370 °C (600–700 °F) ye lead solder uye 350–400 °C (660–750 °F) kuti isashandise mutobvu, yakagadziriswa zvichienderana nehukuru hwemuromo wayo uye huremu hwemajoini.
• Tembiricha yepamusoro inodzokororwa inoiswa padanho re20–40 °C pamusoro pemvura iri mu alloy. Kune SAC305 (mvura ~220 °C) peak yakajairika ndeye 235–250 °Ckune Sn63/Pb37 ine lead, peak yakatenderedza 210–225 °C zvakajairika.

Musiyano uripo pakati penzvimbo yekunyunguduka netembiricha yekushanda ndewemaune: muganho mudiki uye solder hainyatsoyerera zvakanaka (majoini anotonhora, kunyorova kusina kunaka); wakawandisa uye unogona kuisa panjodzi yekusimudza mapedhi, kukuvadza zvikamu zvinonzwa kupisa, kana kudarika tembiricha yegirazi yebhodhi.

Nei nzvimbo yekunyungudutsa solder ichikosha muPCB assembly

Mukugadzirwa, nzvimbo yekunyunguduka ndiyo nhamba iyo tembiricha yega yega inogadzirwa. Kana ukakanganisa wobva warasikirwa negoho. Nzvimbo dzinonyanya kukosha:

• Kudzokorora ruzivo. Iyo four-zone reflow profile (preheat, soak, reflow, cool) yakagadzirwa kubva pa paste alloy's solidus ne liquidus. Iyo peak inofanira kubvisa liquidus nemuganhu wakachengeteka pasina kubika zvikamu - ndosaka iyo process yakagadzirirwa SAC305 yakasiyana neiyo ye leaded process.
• Zvinhu zvebhodhi (Tg). Kupisa kwakanyanya kwepasina mutobvu kunoswedera pedyo nekupisa kwegirazi re laminate, saka Tg yakakwira. FR-4 inowanzo tsanangurwa kuti igadzire zvinhu zvisina mutobvu kudzivirira kupatsanurwa kana kukanganiswa.
• Zviumbwa zvakasanganiswa. Kuisa mabhora ane lead kuburikidza neprofile isina lead (kana kuti zvinopesana) kunoita kuti pave nemajoini asingavimbike. Kuenderana kwealloy kunofanirwa kudzorwa muBOM yese, kunyanya ne BGAs.
• Solder paste nemastencil. Namatidza inoenderana ne alloy, uye huwandu hwakakodzera hwe deposit kubva ku stencil yakachekwa nelaser inoita kuti joini ive nesimbi yakakwana kana flux yapera.
• Sarudzo dzekupisa kushoma. Kana bhodhi riine zvikamu zvisingakwanise kurarama panguva yekudziya kwe245°C, pane kusarudzwa kwechinhu chinopisa zvishoma kana nzira yekusarudza.

Highleap Electronics , kambani inogadzira PCB nePCBA iri kuChina, inoshandisa nzira dze lead nedzisina lead dzine ma profiles e reflow anoenderana ne paste alloy uye thermal mass yebhodhi, zvakasimbiswa neAOI neX-ray pazvikamu zve area-array. Kana usina chokwadi chekuti ndeipi alloy kana finish inokodzera dhizaini yako, ongororo yeDFM inovhara solder alloy, surface finish, uye thermal considerations bhodhi risati ravakwa - chikamu che standard turnkey PCB assembly uye SMT work.

Mibvunzo Inowanzo bvunzwa Pamusoro Pekunyunguduka Kwemuchina Wekunyungudutsa

Ndeipi nzvimbo yekunyunguduka kwe solder muCelsius neFahrenheit?

Zvinoenderana nechinhu chinoshandiswa musanganiswa wesimbi. Chinonyungudika chinowanzo shandiswa nesimbi, Sn63/Pb37, chinonyungudika pa183 °C (361 °F). Chinonyungudika chinowanzo shandiswa nesimbi, SAC305, chinonyungudika pa217–220 °C (423–428 °F).

Ndeipi nzvimbo inonyunguduka yesolder isina mutobvu?

Zvizhinji zvemagetsi zvisina lead zvinonyunguduka pakati pe217 °C ne227 °C. SAC305 iri 217–220 °C, eutectic tin-silver iri 221 °C, uye tin-copper (Sn99.3/Cu0.7) iri 227 °C — inopisa kupfuura 30–45 °C kupfuura tin-lead solder.

Sei eutectic solder ine nzvimbo imwe chete yekunyunguduka?

Chiumbwa che eutectic chakaita seSn63/Pb37 ndicho chinhu chinonyungudutsa uye chinooma patembiricha imwe chete pasina nzvimbo iri pakati pe pasty. Kuchinja uku kwakasimba kunoita kuti pave nemajoini akachena uye kunoita kuti pave nekukwanisa kusungirirana nemaoko.

Ndinofanira kuisa tembiricha yakadii pasimbi yangu yekusonesa?

Pamusoro penzvimbo yekunyunguduka kwesolder saka kupisa kunofambiswa nekukurumidza: inenge 315–370 °C (600–700 °F) yesolder ine lead uye 350–400 °C (660–750 °F) yeisina lead, yakagadziriswa saizi yemuromo uye huremu hwemajoini. Nhamba chaiyo itembiricha inoshanda, kwete nzvimbo yekunyunguduka pachayo.

Tembiricha yekunyungudutsa yakafanana here nenzvimbo yekunyunguduka?

Kwete. Nzvimbo yekunyunguduka ndeye apo solder inova mvura; tembiricha yekusonesa kana yekudzoserwa kwemvura inoiswa pamusoro payo. Mapeji ekudzoserwa kwemvura anowanzova 20–40 °C pamusoro pemvura ye alloy saka solder inonyorova zvakanaka.

Ndinogona here kusanganisa solder ine lead neisina lead?

Zviri nani kudzivirirwa. Kusanganisa ma alloys — semuenzaniso kumhanyisa mabhora eBGA asina lead kuburikidza ne lead profile — kunoita kuti pave nekusawirirana pakati pemetallic ne melting-point izvo zvinokonzera majoini asina kuvimbika. Mukugadzirwa, kuenderana kwe alloy kunodzorwa muunganidzwa wese.

Chii chinonzi solder ine poindi yakaderera yekunyunguduka?

Pakati pezvinhu zvinosanganiswa, indium-tin (In52/Sn48) inonyunguduka pa118 °C uye tin-bismuth (Sn42/Bi58) pa138 °C. Izvi zvinoshandiswa pakupisa kushoma zvinoshandiswa pakugadzira zvinhu zvinonzwa kupisa uye kugadzira step-soldering, kunyange zvazvo bismuth alloys dzichinyanya kuputsika.