Sidewall-Mounted SMDs on Embedded Leadframe SiPs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing microelectronic packaging technologies face challenges in efficiently producing compact and cost-effective System-in-Packages (SiPs) with robust sidewall interconnections, as they often require additional space for surface-mounted devices and may need Organic Solderability Preservation (OSP) coatings for sidewall conductors.
Innovation Solution
The method involves embedding leadframes within molded package bodies, exposing leads through the sidewalls, and mounting Surface Mount Devices (SMDs) directly to these leads for ohmic contact, allowing for compact SiP design without OSP coatings and enabling multiple SMDs in a compact manner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If surface mount devices are mounted on the topside or bottomside of the package, then the package can achieve functional requirements, but the package size increases and space is consumed on the topside and bottomside
Solution Approach 1:
The patent moves surface mount devices from the traditional topside/bottomside mounting locations to the sidewalls of the package. This dimensional relocation allows SMDs to be mounted on the vertical surfaces rather than horizontal surfaces, thereby freeing up the topside and bottomside areas for larger contact arrays or heat sinks while maintaining all necessary functional requirements.
2Area of stationary object
If sidewall conductors are used for interconnections, then space is saved on the topside and bottomside, but OSP coatings are required to ensure solderability
Solution Approach 1:
The patent removes the requirement for OSP coatings by using leadframe leads with existing solderable finishes (such as tin, nickel, or gold plating) that are exposed through the sidewalls. This extraction of the OSP coating requirement simplifies the manufacturing process while maintaining solderability, as the leadframe leads inherently possess solderable surfaces without requiring additional protective coating layers.
3Volume of moving object
If leadframes are embedded within molded package bodies with leads exposed through sidewalls, then compact SiP design is achieved, but additional manufacturing steps are required
Solution Approach 1:
The patent combines multiple functions into the leadframe structure: the leadframe serves as both the structural support for the semiconductor die and as the interconnection carrier with exposed leads for sidewall mounting. By integrating the die support function and the interconnection function into a single leadframe component, the overall device complexity is reduced despite the compact packaging approach.
Data Source
AI summary
Embodiments of a method for fabricating System-in-Packages (SiPs) are provided, as are embodiments of a SiP. In one embodiment, the method includes producing a first package including a first molded package body having a sidewall. A first leadframe is embedded within the first molded package body and having a first leadframe lead exposed through the sidewall. In certain implementations, a semiconductor die may also be encapsulated within the first molded package body. A Surface Mount Device (SMD) is mounted to the sidewall of the first molded package body such that a first terminal of the SMD is in ohmic contact with the first leadframe lead exposed through the sidewall.