锡膏印刷工艺培训教材.pdf

SolderPastePrintingProcess

PL-6TechnologyProcessSharing

PreparedBy:RhodericM.delaCuesta

SMTENGINEER

5’SOFSOLDERPASTEPRINTING

•SolderPaste-Ahomogeneouscombinationofsolderparticles

(rangingindiameterfromabout4to40microns)Solderpasteis

commonlyappliedbyprinting,dispensing,pre-forms,andmanual

methods.

•Stencil-Athinsheetofbrassorstainlesssteelwithopeningsthat

matchthelandpatternoftheprintedcircuitboard.Typically,solderpaste

areforceappliedthroughtheseopeningsontotheprintedcircuitboard

componentpads.

•Squeegee-Ametalorrubberbladeusedinscreenorstencilprinting

towipeacrossthescreen(stencil)toforcesolderpastethrough

openingsinthescreen(stencil).

•Support-AmetalassistanceofPWBthatactasanundersidebraceto

holditinparticularlocation.

•Spatula-Atoolcommonlymadeofmetal,plasticorceramicusedfor

mixing,spreading,cleaninganddistributingsolderpastepriorprinting

THESOLDERPASTE

•Solderpastehasbeenusedinelectronicassemblyformorethan30yearsnow

anditisacomplexmixtureofatleastfiveelements:solderpowder,fluxvehicle

;(rosins/resins,activator,rheologicalcontrolagentsandsolvent).

1.0SolderPowder-generally,theyarewidelyavailableeverywhereinthe

world.Alloycompositiondependsontheneedofmanufacturing.Material

scienceconsiderationareakeyfactorfortheselectionofalloy.

•Alloys-Asubstancewhicharemadeofbymeltingtwoormore

element/materialswithdifferentcombinationtogether.Iftwo

elementarealloyedtogether,theyarecalledbinaryalloy.Ifthree,