Cov txheej txheem tseem ceeb ntawm cov khoom siv tooj liab muaj xws li kev npaj pob tooj liab, nickel electroplating thiab solder plating (nickel plating 2-3 μm, solder plating 3-30 μm xws li SAC305), reflow soldering kub profile thiab plating ua ke tsim. Tag nrho cov txheej txheem yuav tsum sib npaug cov qauv precision thiab soldering kev ntseeg tau.
Kev tsim khoom ntawm tooj liab core solder balls (CCSBs) yog qhov siab -cov txheej txheem sib xyaw ua ke, feem ntau suav nrog cov kauj ruam tseem ceeb hauv qab no:
Copper Ball Preparation: High Sphericity is the Primary Challenge Micron -loj tooj liab pob, feem ntau yog 0.03–0.5 mm inch, yog npaj siv atomization molding los yog electrolytic deposition txoj kev.
Yuav tsum muaj qhov siab tshaj plaws (sphericity).<1 μm) to ensure uniform contact with the pads during ball placement, avoiding cold solder joints or misalignment. The surface needs cleaning and activation treatment to improve the adhesion of subsequent plating layers.
Cov txheej txheem electroplating: Kauj ruam-los ntawm- kauj ruam tso cov txheej txheem ua haujlwm
Nickel Plating Layer (2–3μm): Ib txheej npib tsib xee yog tsim rau saum npoo ntawm lub pob tooj liab los ntawm cov tshuaj plating lossis electroplating. Nws lub luag haujlwm tseem ceeb yog txhawm rau tiv thaiv kev sib cuam tshuam ntawm tooj liab thiab tin ntawm qhov kub thiab txias, tiv thaiv kev loj hlob ntau dhau ntawm brittle intermetallic compounds (IMCs), thiab txhim kho kev ruaj ntseg interface. Cov txheej no yog xaiv tau thiab nyob ntawm cov khoom siv substrate thiab kev ntseeg tau.
Solder Plating Layer (3–30μm): Cov txheej txheej txheej yog plated nrog solderable alloy, feem ntau yog cov hlau lead- dawb solders xws li SAC305 (Sn-3.0Ag-0.5Cu). Lub thickness yog hloov kho raws li qhov sib koom ua ke qhov siab thiab qhov xav tau ntub dej. Cov txheej no melts thaum reflow soldering, ua kom tiav kev sib txuas nrog PCB lossis interposer pads.
