A packaging engineer supporting a multi-function aerospace electronics module faced increasing assembly complexity as system integration advanced. The design incorporated RF die, control electronics, optical components, and high-power devices — each requiring different attachment methods and metallurgical interfaces.
To complete the module, the assembly flow required a combination of:
Traditional substrate platforms forced tradeoffs between these assembly methods. Metallization systems optimized for one attach type often degraded performance or reliability in another. Secondary plating, pad modifications, and localized processing were frequently required to accommodate mixed assembly flows.
These workarounds introduced risk:
The program required a platform that could support multiple assembly methods without compromising reliability, manufacturability, or qualification stability.
Thin Film Designed for Assembly Integration
To simplify manufacturing, the engineering team transitioned to a thin-film substrate platform engineered for assembly flexibility and process stability.
Metallization Systems for Mixed Assembly
Thin-film metallization stacks were configured to support multiple attachment methods on a single surface. An EPIG finish enabled solder attach alongside the gold wire bonds without requiring selective plating.
Sputtered AuSn metallization provided tightly controlled eutectic bonding for laser and high-power device attach, eliminating paste handling, voiding, and bond line variation.
For high-density interconnects, solder and solid metal bump structures supported flip-chip assembly and vertical interconnect architectures.
Mechanical and Interconnect Integration
Solid filled vias, castellated edges, and precision slots simplified module-to-board attachment and vertical signal routing. Sidewall metallization enabled optical component attachment at the package edge, supporting compact system integration.
These features reduced the need for secondary hardware, brackets, and manual assembly fixturing.
Process-Stable, Qualification-Friendly Execution
Through build-to-print discipline, materials, metallization finishes, and inspection processes were locked early in the program lifecycle. Design for Manufacturability (DFM) reviews, First Article Inspections (FAIs), controlled travelers, and full traceability ensured repeatable production after qualification.
By stabilizing both the physical design and assembly metallurgy, the platform minimized requalification risk over long program lifecycles.
Simplified Assembly and Improved Manufacturing Yield
After transitioning to the thin-film platform:
Assembly flows became more streamlined, qualification processes stabilized, and manufacturing yield improved without sacrificing electrical or mechanical performance.
Programs moved from complex, multi-process assembly workarounds to integrated, production-ready packaging platforms.
[Engineering Takeaway]
“Our design required wire bond, solder, eutectic, and flip-chip attach on the same module. Thin film gave us a metallization platform that supported every assembly path without secondary processing or qualification risk.”
— Aerospace Electronics Packaging Engineer
This is our general contact form. If you have more specific questions or needs please select from the options below.
