Fairchild Semiconductor AN9046 Assembly Guidelines for Dual Power56 Packaging

About this manual

The document is an Application Note (AN9046) by Dennis Lang focusing on the assembly of the Fairchild Semiconductor Dual Power56 package. This component utilizes Molded Leadless Packaging (MLP) technology, featuring two large die attach pads for high and low side MOSFETs in synchronous buck DC-DC circuits.

The text details critical board mounting considerations, including PWB design tolerances, pad finishes (specifically NiPdAu lead-free), and the use of vias. It also covers stencil design parameters, solder paste selection (recommending SAC 305), and reflow profiles rated for a peak temperature of 260°C.

What's inside

• Introduction
• Board Mounting
• PWB Design Considerations
• Pad Finish
• Using Vias with Dual Power56
• Stencil Design
• Solder Paste
• Reflow Profile
• Voiding
• Rework

Specifications

Frequently asked questions

What solder alloy is recommended for the Dual Power56?

SAC 305 (96.5 Sn/3.0Au/0.5Cu) is the lead free solder paste alloy of choice.

What is the maximum recommended voiding percentage?

Fairchild recommends a guideline of 25% maximum voiding for MLP type packages.

Can the Dual Power56 be reused after rework?

No, it is recommended that this component not be reused if rework becomes necessary.