Lead vs Lead-Mahara Soldering uye Solder Melting Points muPCB

solder melting point

Indasitiri yezvemagetsi yepasi rose iri kuita shanduko huru yakanangana nemaitiro anochengetedza nharaunda. Chimwe chinhu chakakosha chekuchinja uku kusimuka kubva pachinyakare lead-based soldering kuenda kune lead-yemahara solder muPrinted Circuit Board Assembly (PCBA). Kunzwisisa nuances pakati peidzi nzira mbiri dzekutengesa kwakakosha pakuona kuvimbika, kuita, uye kutevedza kwezvakatipoteredza kwezvigadzirwa zvemagetsi. Ichi chinyorwa chakazara chinotarisa mune tekinoroji maficha, zvinonetsa, uye zvinobatika zvinotariswa zveese maviri matekiniki ekutengesa, zvichipa ruzivo rwakakosha kune nyanzvi muPCB indasitiri.

Kukosha kweSolder Joints

Solder majoini ndiwo musana wemagungano emagetsi, kumisikidza zvese zvemakanika uye magetsi kubatana pakati pezvikamu nePCB. Kutendeseka kwemajoini aya kwakakosha; kunyange imwe yakashata solder joint inogona kukanganisa kushanda kwechigadzirwa chemagetsi. Naizvozvo, kunzwisisa zvivakwa uye maitiro emhando dzakasiyana dzekutengesa kwakakosha kuti uwane kuvimbika kwepamusoro mukugadzirwa kwemagetsi.

Traditional Lead Soldering

Kuumbwa uye Zvivakwa zveLead-Yakavakirwa Solder

Lead-based solder, inowanzoita tin-lead (SnPb) alloy, yanga iri chiyero cheindasitiri kwemakumi emakore. Iyo inonyanya kushandiswa kuumbwa, Sn37Pb, inopa akati wandei anobatsira zvivakwa:

• Kunyorera Point: Iyo eutectic kuumbwa kweSn37Pb inonyunguduka pane yakaderera tembiricha ye183 ° C.
• Kunyorova: Yakanakisa wettability inovimbisa yakasimba uye yakavimbika solder majoini.
• Mechanical Properties: Lead solder yakapfava, inopa kubatwa kwakanaka kwekuvhunduka uye kugovera kushushikana.

Zvakanakira Lead-Based Soldering

Mabhenefiti ekutanga ekushandisa lead solder anosanganisira:

• Low Melting Point: Inofambisa zviri nyore uye zvishoma-simba-yakanyanya-yakawanda solder maitiro.
• Superior Wettability: Inovimbisa kunamatira kwakasimba pakati pezvikamu uye PCBs.
• Kuvimbika Mechanical Performance: Kupfava kweiyo solder kunobatsira kutora ma mechanic stress, kuwedzera kusimba kwemajoini.

Njodzi Dzehutano Nezvakatipoteredza

Pasinei nehunyanzvi hwayo hwehunyanzvi, lead ine muchetura zvakanyanya, ichiunza njodzi huru dzehutano kuvashandi uye njodzi dzezvakatipoteredza. Izvi zvakaita kuti pave nemirau yakasimba uye kusundidzira kwepasirese kubvisa lead pamagungano emagetsi.

solder melting point

Lead-Yemahara Soldering

Kuumbwa uye Zvivakwa zveLead-Yemahara Solder

Lead-isina solder alloys, anonyanya kuumbwa netin-silver-copper (SAC) maumbirwo akaita seSAC305 (96.5% Sn, 3.0% Ag, 0.5% Cu), akabuda seimwe nzira inoenderana nenharaunda. Zvinhu zvakakosha zvinosanganisira:

• Kunyorera Point: SAC305 inonyunguduka panenge pa217°C, yakakwira kudarika lead-based solder.
• Kunyorova: Kazhinji hurombo kupfuura lead solder, zvichidikanwa zvakanyanya kushanda.
• Mechanical Properties: Majoini ekutengesa asina mutobvu anowanzova akaoma uye akawedzera brittle.

Zvinetso zveLead-Yemahara Soldering

Kuchinjira kune lead-isina soldering kunounza matambudziko akati wandei:

• Higher Melting Point: Inoda tembiricha yepamusoro yekugadzirisa, kuwedzera kupisa kushushikana pane zvikamu uye maPCB.
• Brittleness: Lead-isina solder majoini anowanzo putika uye kuneta, kunyanya pasi pemamiriro ekupisa kwebhasikoro.
• Wettability Issues: Kusanyorova kunyorova kunogona kutungamirira kumajoini asina kukwana kana asina kusimba, zvinoda kunyatso kudzora kwema parameter ekutengesa.

Kuenzanisa Kwakazara Pakati Pekutungamirira uye Kutungamira-Mahara Soldering

Melting Point uye Thermal Stress

Iko kushanduka kubva kune-lead-based to lead-free soldering kunosanganisira kuchinja kukuru muhuwandu hwekupisa kwekugadzirisa. Vatengesi vasina lead, vakaita seaya akavakirwa patin-silver-copper (SAC) alloys, ane mapoinzi ekunyungudika akakwira (anosvika 217°C) zvichienzaniswa neyekare tin-lead (SnPb) solder (183°C). Iyi nzvimbo yepamusoro yekunyungudika inowedzera kupisa kwemafuta panguva yekuungana, zvichitungamira kune akati wandei angangoita nyaya:

• Warping: Iyo tembiricha yepamusoro inogona kukonzera iyo PCB substrate kutenderera, kunyanya kana isina kupisa zvakafanana.
• Delamination: Iwo akaturikidzana ePCB anogona kupatsanura pasi pekunetseka kwekushisa kwepamusoro.
• Chikamu Kukuvadza: Sensitive zvikamu zvinogona kusamira nepamusoro tembiricha yekuyerera inodiwa kune lead-isina soldering.

Kuti uderedze njodzi idzi, kungwarira kutonga kwekupisa kwakakosha. Izvi zvinosanganisira kukwidziridza iyo reflow mbiri kuti ive nechokwadi chekudziya, kushandisa preheating nhanho kudzikisa kupisa kuvhunduka, uye kusarudza zvinhu zvine yakanyanya kugadzikana kwemafuta.

Mechanical Kuvimbika

Mechanical kuvimbika chinhu chakakosha mukuita solder joint performance. Majoini emasoja asina lead anowanzo kuoma uye akaonda zvakanyanya kana achienzaniswa neawo anotungamira-anotungamirwa nawo. Uyu mutsauko mune zvemakanika zvinhu une zvakawanda zvinorehwa:

• Kutsemuka: Iyo brittleness yemasoja asina mutobvu anoita kuti vanyanye kutsemuka pasi pekunetseka kwemichina.
• Kuneta: Kudzokororwa kupisa bhasikoro, kunowanikwa mumotokari uye aerospace zvemagetsi, zvinogona kutungamirira kuneta kukundikana mu lead-isina solder majoini.

Kugadzirisa matambudziko aya kunoda nzira dzakananga, dzakadai se:

• Alloy Selection: Kushandisa alloys ane zvidiki zvekuwedzera zvezvinhu zvakaita sebismuth kana nickel zvinogona kuvandudza ma mechanika emasoja asina lead.
• Yakabatana Dhizaini: Kugadzira majoini e solder kugovera kushushikana zvakanyanya zvakaenzana uye kuderedza nzvimbo dzekusimbisa.
• Reinforcement Techniques: Kushandisa underfill kana dzimwe nzira dzekusimbisa kutsigira majoini ekutengesa uye kuwedzera kusimba kwawo.

Wettability uye Joint Formation

Wettability chinhu chakakosha chinokanganisa kuumbwa uye kuvimbika kwemajoini ekutengesa. Lead-based solders vanoratidza kunyorova kwakanakisa, vachigadzira majoini akasimba uye akavimbika nekuedza kushoma. Kusiyana neizvi, vatengesi vasina lead vanowanzo tambura nekunyorova, zvichitungamira kune zvinogona kuitika:

• Kunyorova Kusina Kukwana: Kusadzika kwemvura kunogona kukonzera kuvhara kusina kukwana kwepadhi, zvichiita kuti zvive zvisina simba majoini.
• Voiding: Mhepo yakavharirwa kana masara emvura anogona kugadzira voids mukati mejoint ye solder, kukanganisa kutendeseka kwayo kwemagetsi nemagetsi.

Kuve nechokwadi chekugadzirwa kwemhando yepamusoro-soro nemasoja asina lead, nzira dzinoverengeka dzinogona kushandiswa:

• Active Fluxes: Kushandisa yakawanda inoshanda flux formulations inosimudzira kunyorova uye kuderedza oxidation.
• Optimized Soldering Parameters: Kugadzirisa tembiricha yekutengesa, nguva, uye mamiriro ekunze kuti uwedzere kunyorova.
• Pamusoro Kugadzirira: Kuve nechokwadi chekuti nzvimbo dzichatengeswa dzakachena uye hadzina okisidhi.

Environmental and Health Impact

Chinonyanya kukonzera kuti vanhu vashandukire kuita zvinhu zvisina mutobvu ndiko kudzikira kukuru kwenjodzi dzezvakatipoteredza nedzehutano dzine chekuita nekusangana neutobvu. Mutobvu chinhu chine chepfu chinokonzera njodzi huru kuhutano hwevanhu nenharaunda, zvichikonzera mitemo yakaoma yakaita semirairo yeRestriction of Hazardous Substances ( RoHS ). Kubatanidza zvinhu zvisina mutobvu kune mabhenefiti akati wandei panyaya iyi:

• Yakaderedzwa Toxicity: Kubvisa mutobvu kubva mukugadzira solder kunoderedza zvakanyanya njodzi yekufumurwa kune vashandi uye kunoderedza kusvibiswa kwezvakatipoteredza.
• Kuteerera Kwemitemo: Kugamuchira lead-isina soldering maitiro kunovimbisa kuteedzera kwepasirese mitemo yezvakatipoteredza.

Nekudaro, lead-isina soldering haina kutengeserana kwayo. Iwo epamusoro ekugadziridza tembiricha anodiwa kune vatengesi vasina-lead anowedzera kushandiswa kwesimba, izvo zvinogona kukanganisa iyo yakazara nharaunda tsoka. Kuti vaenzanise izvi zvinonetsa, vagadziri vanogona kushandisa maitiro ekushandisa simba, akadai se:

• Kushanda Kwekupisa Kwekupisa: Kugadziridza reflow ovheni uye zvimwe zvekudziya midziyo kuderedza kushandiswa kwesimba.
• Advanced Materials: Kugadzira uye kushandisa zvinhu zvinogonesa kudzika-tembiricha lead-isina soldering maitiro.
• Kudzokorodza uye Kutarisira Waste: Kuvandudza kuedza kudzokorodza uye kugadzirisa marara kuderedza kukanganisa kwezvakatipoteredza.

Kuenzanisa Kwakadzama Kwechimiro Chemuviri

Kutaridza mutsauko uripo pakati pemutobvu nekutengesa-isina lead, heino kuenzanisa kwakadzama kwezvimiro zvavo zvemuviri:

Kuenzanisa Kwakadzama Kwechimiro Chemuviri

Zvinetso muLead-Yemahara Soldering

Oxidation

Kupisa kwekushisa kwepamusoro kunowedzera njodzi ye oxidation, iyo inogona kukanganisa hutano hwemasolder joints. Dambudziko iri rinoda zvirinani magadzirirwo ekuyerera uye anodzorwa solder nharaunda kuchengetedza kubatana kutendeseka.

Component Compatibility

Zvimwe zvinhu, kunyanya zviya zvine mapakeji epurasitiki kana electrolytic capacitor, zvinogona kusamira netembiricha yepamusoro inodiwa pakusodha isina lead. Kunyatsosarudzwa kusarudzwa kwezvikamu uye zvingave zvigadziridzo zvekugadzirisa zvakakosha kuti zvive nechokwadi chekuenderana.

Tin Whiskers

Masoja asina mutobvu, kunyanya aya ane marata akakwirira, anokasika kukura ndebvu, izvo zvinogona kukonzera zvikabudura zvemagetsi. Mazano ekuderedza anosanganisira kushandisa zvipingamupinyi zvakasara se nickel uye kusarudza maumbirwo akakodzera alloy.

Conductive Anodic Filament (CAF)

Lead-yemahara soldering inogona kuwedzera kuumbwa kweCAF muPCBs, zvichitungamira kumapfupi maseketi uye kutadza. Zvinhu zvakasimba uye zvidzoreso zvemaitiro zvakakosha kudzivirira nyaya iyi, kunyanya mumagungano epamusoro-soro.

Mafungiro Anoshanda eKuchinjisa kune Lead-Yemahara Soldering

Process Adjustment

Kushandura kuenda kune lead-isina soldering kunoda kugadziridzwa mukupisa tembiricha, nguva profiles, uye chiyero chemidziyo kuti igamuchire nzvimbo dzakakwirira dzekunyungudika uye akasiyana ekuyerera maitiro easina lead-alloys.

Kusarudzwa Kwezvinhu

Kusarudza zvinhu zvakakodzera kwakakosha. Zvikamu zvinofanirwa kukwanisa kumira tembiricha yakakwira, uye maPCB anofanirwa kuve neakakodzera Tg (girazi shanduko tembiricha) kukosha. Izvi zvinoita kuti gungano rikwanise kutsungirira iyo lead-yemahara soldering maitiro pasina kukanganisa kuita.

Dhizaini Yekugadzira (Dfm)

Misimboti yeDFM inofanirwa kugadziridzwa kuti igadzirise kutonga kwekupisa, kuvimbika kwemubatanidzwa, uye kuiswa kwechikamu. Kugadziridza madhizaini epadhi uye kuve nechokwadi chekuzorora kwakaringana kwekupisa kwakakosha pakubudirira kusinga dhadhadha.

Quality Control

Matanho ekudzora hunhu akawedzerwa, anosanganisira kuongororwa kweX-ray uye kuongororwa kweotomatiki kwemaziso (AOI), anodiwa kuti aone nekugadzirisa zvikanganiso zvakanangana nekusungirirwa kwesimbi isina mutobvu. Kuongorora uku kunobatsira kuona kuvimbika kwemajoini esimbi uye mhando yese yesimbi.

Mafungiro Akakosha eCAM Injiniya

Surface Finish Type uye Impact paGerber File Kusikwa

Pakugadzira mabhodhi ane density yakakura, mainjiniya eCAM anofanirwa kufunga nezvemhando yekupedzisa pamusoro. Pamagadzirirwo epamusoro akapfapfaidzwa netini, kukosha kwekuboorwa nekufambiswa kwenzira kwakakwira zvichienzaniswa nemagadzirirwo epamusoro asina kupfapfaidzwa netini. Izvi zvinoda kunyatsofungisisa nezvemaitikiro epamusoro, saizi yekuboorwa, uye upamhi nenzvimbo yemavara. Pamusoro pezvo, kusungirirwa kwesimbi kusina lead, nekupisa kwayo kwakanyanya, kunokanganisa kuwedzera kwemavara ekupisa. Naizvozvo, upamhi hwemavara ekutevera hunofanirwa kugadzirwa kuti hubate mutoro wemagetsi unotarisirwa pasina kupisa zvakanyanya. Kureba kwakakodzera pakati pemavara ekutevera kwakakoshawo kudzivirira mapfupi, kunyanya mumagadzirirwo ane density yakawanda.

Magetsi uye Kupisa Kufunga

Mhando yekupedzisa kwepamusoro inokanganisa zvakananga bhodhi ukobvu uye solder mask clearance. Kupedzwa kwakasiyana kune siyana ukobvu zvinodiwa; semuenzaniso, kupfapfaidza tini kunoda kutarisisa kune thinnest board ukobvu kudzivirira bhodhi kuti risaputirwe mukati mekuita. Pamusoro pezvo, iyo yekumusoro kupera inokanganisa inodiwa solder mask clearance. Tin-sprayed finishes ane akasiyana emuviri zvimiro pane asiri-tin-sprayed finishes, zvichida kugadziridzwa kwakanangana nekugadziriswa kuti ive nechokwadi chekushanda kwakakwana uye kuvimbika.

Solder Mask Dhizaini uye Pad Layout

Mune solder mask dhizaini, zvakakosha kuti uve nechokwadi chekuwedzera kwakaringana kutenderedza mapedhi kuti ugare yakasarudzwa solder pamusoro pekupedzisira. Inotungamira-isina kupedzisa, iyo inowanzo sanganisira yakakwirira solder tembiricha, ingangoda kuwedzera zvishoma kuti utsungirire kushushikana kwekupisa. Kunyatsorongeka kweiyo solder mask kune pad kwakakosha, sezvo kusarongeka kunogona kutungamira kune solder bridging kana kushata majoini ekutengesa. Nezve padhi dhizaini, kuchengetedza saizi yepadhi inowirirana uye chimiro kwakakosha kune maunifomu solder majoini. Izvi zvinonyanya kukosha kune lead-isina soldering, uko yakaoma uye yakawanda brittle majoini inoda chaiyo padhi dhizaini kudzivirira kutadza kwemagetsi. Via-mu-pad madhizaini anofanirwa kudzivirirwa kunze kwekunge akanyatsozadzwa uye akavharirwa kudzivirira solder wicking uye voiding.

mhedziso

Kuchinja kubva pakusanganisa zvinhu zvisina mutobvu kuenda pakusanganisa zvinhu zvisina mutobvu muPCBA kunokonzerwa nepfungwa dzezvakatipoteredza nehutano, zvichikonzera matambudziko makuru ehunyanzvi. Kunzwisisa mutsauko uripo muhunhu hwemuviri, zvinodiwa pakuita zvinhu, uye nzira dzinogona kukundikana kwakakosha pakuwana majoini ekugadzira zvinhu akavimbika uye emhando yepamusoro mukubatanidza zvinhu zvisina mutobvu.

Nepo kutungamira-isina kushambadzira kunopa zvipingamupinyi senge tembiricha yepamusoro yekugadzirisa, kuwedzera oxidation, uye zvinogona kuvimbika nyaya, izvi zvinogona kudzikiswa kuburikidza nekuchenjerera maitiro ekudzora, kusarudzwa kwezvinhu, uye dhizaini inogadziriswa. Sezvo iyo indasitiri iri kuramba ichishanduka, kutsvagisa kuri kuramba kuchiitika uye kufambira mberi kwetekinoroji kuchawedzera kuvimbika uye kuita kwekutengesa-isina kutengesa mukugadzira zvemagetsi.