Lead Frame Packaging

PackagePrep Solderable Finish

solder flank.jpgQFN Packages:  Small, Thin, and Now Inspection Friendly

QFN’s have become the preferred high density leadframe-based surface mount package. But the advantage of this versatile package comes at a price. Exposed copper at the singulated edge of the package solders poorly, preventing conventional solder fillets from forming. The lack of a visible solder fillet inhibits recognition by automated optical inspection (AOI). Furthermore, the smaller solder footprint creates reliability risk, limiting the end-use applications that designers will consider.

PackagePrep solves these problems. PackagePrep deposits an easily soldered metal finish on the exposed copper edges. After paste reflow, solder wicks up the side of the QFN flanks. The new QFN fillets are easily inspected by existing top-down AOI as well as visual inspection, supplementing x-ray inspection.

Planning to use QFN’s in your high reliability application, but concerned about reliability and inspectability? Let PackagePrep be your solution.

shutterstock_129319766.jpgComponents that operate in harsh environments, such as automotive and aerospace assemblies, must meet more stringent demands than other components. They must endure high temperatures, mechanical stress and corrosive conditions.  While meeting reliability standards, components for automotive applications also require high density performance.  The leadframe based QFN surface mount component has been a preferred product to meet both the reliability and higher density requirements and continues to show significant market growth.  A past limitation has been the inspection difficulty of the assembled QFN. Before PackagePrep, terminal solder joints on QFN’s were hidden under the package and could only be inspected by x-ray. Exposed copper alloy on the outer QFN edges was often missing a visible solder fillet on the flank.  PackagePrep enables AOI inspection of the singulated copper flanks and provides quality solder fillets through a simple plating process with the lowest overall cost among competing technologies.


PackagePrep callout.jpgPackagePrep prepares and plates  the exposed copper alloy edges of QFN packages. The metal coating preserves solderability, meeting JEDEC standards. The soldered coating allows for a three dimensional solder joint that is stronger and more easily inspected than alternative technologies.

Adhesion Promotion for Lead Frames

PackageBond

Proven Reliability At MSL-1 Without Delamination

MacDermid Enthone’s PackageBond is the no risk new_leadframes.jpgadhesion promotion system specifically engineered for reliability at today’s intense lead-free circuit assembly temperatures. Production proven in high-volume at premier semiconductor manufacturing facilities, our advanced laboratory innovations deliver extreme heat tolerance.

PackageBond features patented chemistries that prevent delamination failure of molded packages due to moisture/reflow sensitivity. The process roughens copper alloy leadframes to maximize resin and encapsulant adhesion, plus deposits a thin adhesion booster for long-term delamination protection. PackageBond does not degrade Ag or Ni/Pd/Au plated leadframes, leaving these surfaces clean for predictably strong wire bonds. Production results confirm consistent compatibility with die attach adhesives and no adverse effects on resin bleed.

For exceptional reliability at all moisture sensitivity levels without delamination and the risk of damage to leadframe platings, choose PackageBond.

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Resin Bleed on
Untreated Surface   

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Reduced Resin Bleed with  
PackageBond Anti-Bleed

PackageBond is the advanced leadframe adhesion technology that is designed to overcome delamination problems to achieve MSL-1 reliability. The result of rigorous testing with consistent in-market success, PackageBond is the optimum choice for high density, complex packages and can be run in strip-to-strip or reel-to-reel mode.

MacDermid Enthone, a world leader in advanced surface finishes, is dedicated to satisfying the evolving needs of the semiconductor industry and continuing its tradition of providing benchmark customer and technical support.

No Surface Treatment of Leadframe

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Red illustrates cracks from popcorning
effect during reflow cycle

Packagebound Surface Treatment

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No red illustrates no separation
during reflow cycle

non_surface_leadframe.png
Leadframe surface
before treatment
Treated Alloy.JPG
Leadframe surface
after treatment


PackagePrep Key Features

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PackageBond Key Features

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