SOLDER PASTE JETTING, AN INTEGRAL APPROACH

摘要

Solder paste is a very common material used in SMT processes. Typical methods for applying solder paste to devices are needle dispensing or screen printing, each one has benefits and drawbacks that will be covered. Jetting of solder pastes enable higher throughputs than needle dispensing while eliminating the material waste generated by screen printing. To achieve these results an integral approach starts at the machine focusing on high speed and accuracy, then the software where true jetting on the fly algorithms must be designed and finally, the jet valve itself focusing on volumetric repeatability without damaging the solder balls. Volumetric repeatability of the jetted solder paste is critical to enable the versatility of a screen printer on a dispenser. Data will be presented demonstrating equipment accuracy for jetting solder paste, jetted process capability for a given output and jetting process capability for varying outputs within a single board. Throughput comparisons will be presented to understand how jetting fares against both needle dispensing and screen printing.