Reflow soldering ndiyo inonyanya kushandiswa pamusoro pechikamu welding nzira muSMT indasitiri.Imwe nzira yewelding ndeye wave soldering.Reflow soldering inokodzera chip zvikamu, nepo wave soldering yakakodzera pini yemagetsi zvikamu.
Reflow soldering zvakare iri reflow soldering maitiro.Nheyo yayo ndeyekudhinda kana kujekiseni yakaringana yesolder paste paPCB pad uye kunamira iyo inoenderana SMT chigamba chekugadzirisa zvikamu, wobva washandisa inopisa mhepo inopisa yekupisa yevira reflow kunyungudutsa solder paste, uye pakupedzisira kuumba yakavimbika solder joint. kuburikidza nekutonhodza.Batanidza izvo zvikamu nePCB pad kuti uite basa rekubatanidza mechaniki uye kubatanidza magetsi.Kazhinji kutaura, reflow soldering yakakamurwa kuita nhanho ina: preheating, kugara tembiricha, kuyerera uye kutonhora.
1. Preheating zone
Preheating zone: ndiyo yekutanga kupisa nhanho yechigadzirwa.Chinangwa chayo ndechekukurumidza kupisa chigadzirwa pakupisa kwekamuri uye kumisa solder paste flux.Panguva imwecheteyo, ihwowo nzira yekudziya inodiwa kuti udzivise kushayikwa kwekupisa kwezvikamu zvinokonzerwa nepamusoro-tembiricha yekukurumidza kupisa panguva yekunyudzwa kwetin kunotevera.Naizvozvo, pesvedzero yekukwira kwekushisa pachigadzirwa yakakosha zvakanyanya uye inofanirwa kudzorwa mukati mehumwe hunoenderana.Kana ikanyanya kukurumidza, inoburitsa kuvhunduka kwemafuta, PCB uye zvikamu zvinokanganiswa nekushushikana kwekupisa uye kukonzera kukuvara.Panguva imwecheteyo, iyo inonyungudutsa mune solder paste inoputika nekukurumidza nekuda kwekupisa nekukurumidza, zvichikonzera kupuruzira uye kuumbwa kwe solder bead.Kana ikanyanya kunonoka, solder paste solvent haizonyungudika zvizere uye inokanganisa kunaka kwewelding.
2. Constant tembiricha zone
Constant tembiricha zone: chinangwa chayo ndechekudzikamisa tembiricha yechinhu chimwe nechimwe paPCB uye kusvika pachibvumirano nesezvinogoneka kudzikisa mutsauko wekushisa pakati pechinhu chimwe nechimwe.Panguva ino, nguva yekudziya yechikamu chimwe nechimwe chakareba, nekuti zvidiki zvinotanga kusvika pachiyero nekuda kwekupisa kushoma kunyura, uye zvikamu zvakakura zvinoda nguva yakakwana yekubata nezvikamu zvidiki nekuda kwekupisa kukuru, uye kuve nechokwadi chekuti flux. mu solder paste yakanyungudika zvizere.Panguva ino, pasi pekuita kwekuyerera, iyo oxide pane padhi, solder bhora uye chikamu chepini ichabviswa.Panguva imwecheteyo, iyo inoyerera ichabvisawo kusvibiswa kwemafuta pamusoro pechikamu uye padhi, kuwedzera nzvimbo yewelding uye kudzivirira chikamu kuti chisave oxidized zvakare.Mushure meichi nhanho, zvese zvinongedzo zvinofanirwa kuchengetedza zvakafanana kana zvakafanana tembiricha, kana zvisina kudaro welding inogona kuitika nekuda kwekunyanya kupisa mutsauko.
Iyo tembiricha uye nguva yekugara tembiricha zvinoenderana nekuoma kwePCB dhizaini, mutsauko wezvikamu zvemhando uye huwandu hwezvikamu.Kazhinji inosarudzwa pakati pe120-170 ℃.Kana iyo PCB yakanyanya kuomarara, tembiricha yekugara tembiricha tembiricha inofanirwa kutariswa nerosin inopfavisa tembiricha sereferensi, kuitira kudzikisa nguva yewelding yereflow zone muchikamu chinotevera.Iyo inogara tembiricha nzvimbo yekambani yedu inowanzosarudzwa pa160 ℃.
3. Reflux nzvimbo
Chinangwa cheiyo reflow zone ndechekuita kuti solder paste inyunguduke uye kunyorovesa padhi pamusoro pechinhu chinosungirirwa.
Kana iyo PCB board ichipinda munzvimbo yekuyerera, tembiricha inokwira nekukurumidza kuita kuti solder paste isvike pakunyungudika.Nzvimbo yakanyunguduka ye lead solder paste SN: 63 / Pb: 37 is 183 ℃, uye inotungamira-isina solder paste SN: 96.5/ag: 3 / Cu: 0. Iyo inonyunguduka ye5 i217 ℃.Muchikamu chino, iyo heater inopa kupisa kwakanyanya, uye tembiricha yevira ichaiswa kune yakakwirira kwazvo, kuitira kuti solder paste tembiricha ikwire nekukurumidza kusvika pakakwirira tembiricha.
Iyo tembiricha yepamusoro yereflow soldering curve inowanzo tsanangurwa nenzvimbo yekunyunguduka yesolder paste, PCB bhodhi uye tembiricha inodzivirira kupisa kwechikamu chacho.Iyo yepamusoro tembiricha yezvigadzirwa munzvimbo inoyerera inosiyana zvichienderana nerudzi rwesolder paste inoshandiswa.Kazhinji, tembiricha yepamusoro ye lead-isina solder paste inowanzo 230 ~ 250 ℃, uye iyo ye lead solder paste inowanzo 210 ~ 230 ℃.Kana tembiricha yepamusoro yakanyanya kuderera, zviri nyore kugadzira inotonhora welding uye kusakwana kunyorova kwemasolder joints;Kana yakanyanya kukwirisa, iyo epoxy resin type substrate uye mapurasitiki anowanzo kubikira, PCB inopupuma uye delamination, uye zvakare zvinotungamira mukuumbwa kweakawandisa eutectic simbi makomisheni, zvichiita kuti solder joint brittle uye simba rewelding rishaye simba, zvichikanganisa mechanical properties yechigadzirwa.
Zvinofanira kusimbiswa kuti flux mu solder paste munzvimbo ye reflow inobatsira kukurudzira wetting pakati pe solder paste uye chikamu chekugadzirisa kuguma uye kuderedza kushushikana kwepamusoro kweiyo solder paste panguva ino, asi kukurudzirwa kwekuyerera kuchaita. kudziviswa nekuda kweokisijeni yasara uye masimbi epamusoro oxides muvira reflow.
Kazhinji, yakanaka tembiricha tembiricha curve inofanira kusangana kuti tembiricha yepamusoro penzvimbo imwe neimwe paPCB inofanirwa kuenderana nepazvinobvira, uye mutsauko haufanirwe kudarika 10 madhigirii.Nenzira iyi chete tinogona kuve nechokwadi chekuti zviito zvese zvekushongedza zvakapedzwa zvakanaka kana chigadzirwa chapinda munzvimbo inotonhorera.
4. Nzvimbo yekutonhora
Chinangwa chenzvimbo yekutonhodza ndechekukurumidza kutonhorera yakanyungudutswa solder paste zvimedu uye nekukurumidza kugadzira majoini anopenya emasoja ane inononoka radian uye yakazara tin.Naizvozvo, mafekitori mazhinji anozodzora nzvimbo yekutonhora zvakanaka, nekuti inokodzera solder kuumba majoini.Kazhinji, kukurumidza kutonhora kutonhora kuchaita kuti inonoke kuti yakanyungudutswa solder paste itonhore uye bhafa, zvichikonzera kukwenya, kurodza uye kunyange maburrs eakagadzirwa solder joint.Kunyanya kutonhora kutonhora kuchaita kuti base base yePCB pad pamusoro ibatanidzwe mune solder paste, ichiita iyo solder joint rough, isina chinhu welding uye yakasviba solder joint.Uyezve, magazini ose simbi pachikamu solder kuguma achanyunguduka panguva solder akabatana chinzvimbo, zvichiguma nyoro kuramba kana murombo nomoto pachikamu solder kuguma, Zvinokanganisa nomoto unhu, saka yakanaka kutonhora mwero inokosha zvikuru solder majoini kuumba. .Kazhinji, mutengesi wepaste anokurudzira chiyero chekutonhodza chejoint ≥ 3 ℃ / s.
Chengyuan indasitiri ikambani inoshanda mukupa SMT uye PCBA yekugadzira mutsara michina.Inokupa iwe sarudzo yakakodzera kwazvo.Iyo ine makore mazhinji ekugadzira uye R & D ruzivo.Nyanzvi dzehunyanzvi dzinopa nhungamiro yekuisa uye mushure mekutengesa-musuo nesuo sevhisi, kuitira kuti usanetsekane kumba.
Nguva yekutumira: Kubvumbi-09-2022