l Iimfuno zobushushu obuphezulu obungenalo lead kwizixhobo zezixhobo
Imveliso engenalothe ifuna izixhobo zokumelana namaqondo obushushu aphezulu kunemveliso enelothe.Ukuba kukho ingxaki ngezixhobo zezixhobo, uthotho lweengxaki ezifana ne-warpage ye-furnace cavity, ukuguqulwa komkhondo, kunye nokusebenza kakubi kokutywinwa kuya kwenzeka, okuya kuthi ekugqibeleni kuchaphazele kakhulu imveliso.Ngoko ke, umzila osetyenziswe kwi-oven yokubuyisela i-lead-free-reflow kufuneka uqiniswe kunye nolunye unyango olukhethekileyo, kwaye i-sheet metal joint joints kufuneka ihlolwe nge-X-ray ukuqinisekisa ukuba akukho zintanda kunye namaqamza ukuphepha umonakalo kunye nokuvuza emva kokusetyenziswa kwexesha elide. .
l Ukuthintela ngokufanelekileyo i-warpage yesithando somlilo kunye nokuguqulwa kwesiporo
Umgodlo wesithando somlilo esine-lead-free reflow soldering kufuneka senziwe ngeqhekeza elipheleleyo lesinyithi.Ukuba umngxuma udityaniswe ngamaqhekeza amancinci esinyithi, ithanda ukuba ne-warpage kwiqondo lobushushu elingenalo lead.
Kuyimfuneko kakhulu ukuvavanya ukuhambelana kweereyili phantsi kweqondo lokushisa eliphezulu kunye nokushisa okuphantsi.Ukuba umzila ukhubazekile kwiqondo lokushisa eliphezulu ngenxa yempahla kunye noyilo, ukwenzeka kwe-jamming kunye nokuhla kwebhodi kuya kuphepheka.
l Kuphephe ukuphazamisa amalungu e-solder
I-solder yangaphambili ye-Sn63Pb37 yi-alloy eutectic, kwaye indawo yayo yokunyibilika kunye neqondo lomkhenkce liyafana, zombini kwi-183 ° C.I-lead-free solder joint of SnAgCu ayikho i-eutectic alloy.Indawo yayo yokunyibilika isuka kuma-217°C ukuya kuma-221°C.Iqondo lobushushu lingaphantsi kwe 217°C kwimo eqinileyo, kwaye iqondo lobushushu lingaphezulu kwe 221°C kwimo yolwelo.Xa ubushushu buphakathi kwe-217 ° C ukuya kwi-221 ° C I-alloy ibonisa imeko engazinzanga.Xa i-solder joint ikule meko, ukungcangcazela komatshini wesixhobo kunokutshintsha ngokulula i-solder joint shape kwaye kubangele ukuphazamiseka kwe-solder joint.Esi sisiphene esingamkelekanga kumgangatho we-IPC-A-610D yeemeko ezamkelekileyo zeemveliso zombane.Ke ngoko, inkqubo yokuhanjiswa kwezixhobo ze-lead-free reflow soldering kufuneka ibe noyilo oluhle lwesakhiwo esingena-vibration ukuphepha ukuphazamisa amalunga e-solder.
Iimfuno zokunciphisa iindleko zokusebenza:
l Ukuqina kwe-oven cavity
I-warpage yesithando somlilo kunye nokuvuza kwezixhobo kuya kubangela ngokuthe ngqo ukunyuka komgca kwisixa senitrogen esetyenziselwa umbane.Ngoko ke, ukutywinwa kwezixhobo kubaluleke kakhulu kulawulo lweendleko zemveliso.Uqheliselo lubonakalise ukuba ukuvuza okuncinci, nokuba ngumngxuma ovuzayo olingana nomngxuma wesikrufu, unokunyusa ukusetyenziswa kwenitrogen ukusuka kwi-15 cubic metres ngeyure ukuya kuma-40 eetyhubhic metres ngeyure.
l Ukusebenza kwe-thermal insulation yezixhobo
Chukumisa umphezulu we-oven reflow (isikhundla esihambelana nendawo yokubuyisela kwakhona) akufanele uzive ushushu (ubushushu bomhlaba kufuneka bube ngaphantsi kwama-60 degrees).Ukuba uziva ushushu, kuthetha ukuba ukusebenza kwe-thermal insulation ye-oven reflow ihlwempuzekile, kwaye umthamo omkhulu wamandla ombane uguqulwa ube ngubushushu kwaye ulahlekile, obangela inkunkuma yamandla engadingekile.Ukuba ehlotyeni, amandla obushushu alahlekileyo kwi-workshop aya kubangela ukuba ukushisa kwe-workshop kuphakame, kwaye kufuneka sisebenzise isixhobo somoya-moya ukukhupha amandla okushisa ngaphandle, okukhokelela ngokuthe ngqo kwi-double inkunkuma yamandla.
l Ukukhupha umoya
Ukuba izixhobo azikho inkqubo yokulawula i-flux efanelekileyo, kwaye ukukhutshwa kwe-flux kwenziwa ngokukhupha umoya, ngoko ke izixhobo ziya kukhupha ukushisa kunye ne-nitrogen ngelixa zikhupha i-residu ye-flux, ebangela ngokuthe ngqo ukwanda kokusetyenziswa kwamandla.
l Iindleko zokugcina
I-oven yokubuyisela imveliso iphezulu kakhulu kwimveliso eqhubekayo, kwaye inokuvelisa amakhulu eebhodi zeesekethe zeselfowuni ngeyure.Ukuba iziko linexeshana elifutshane lokulungisa, umsebenzi omkhulu wokulungisa, kunye nexesha elide lokulondolozwa, ngokuqinisekileyo liya kuthatha ixesha elingakumbi leMveliso, nto leyo ekhokelela kwinkcitho yokusebenza kakuhle kwemveliso.
Ukuze kuncitshiswe iindleko zokulungiswa, izixhobo zokuthengisela i-lead-free reflow soldering kufuneka zifakwe kwimodyuli kangangoko kunokwenzeka ukubonelela lula ukugcinwa kwezixhobo kunye nokulungiswa (Umfanekiso 8).
Ixesha lokuposa: Aug-13-2020