Invention Grant
- Patent Title: Method for creating a wettable surface for improved reliability in QFN packages
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Application No.: US16027558Application Date: 2018-07-05
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Publication No.: US10916448B2Publication Date: 2021-02-09
- Inventor: Sadia Naseem , Vikas Gupta
- Applicant: Texas Instruments Incorporated
- Applicant Address: US TX Dallas
- Assignee: Texas Instruments Incorporated
- Current Assignee: Texas Instruments Incorporated
- Current Assignee Address: US TX Dallas
- Agent Dawn Jos; Charles A. Brill; Frank D. Cimino
- Main IPC: H01L23/495
- IPC: H01L23/495 ; H01L21/48

Abstract:
The disclosed principles provide for implementing low-cost and fast metallic printing processes into the QFN and other no-leads package assembly flow to selectively print solderable material in areas that would otherwise be susceptible to corrosion and thus pose reliability risks. The problem of copper corrosion and poor BLR performance in no-leads packages because of remaining exposed copper areas after package singulation is solved by employing selective metallic printing processes in the assembly flow to coat all risk-prone areas with solder material. For example, for no-leads packages that are formed using printed leadframes, solder can be deposited through inkjet, screen, stencil, or photonic printing into the grooves which are formed after passivating the packages at the strip level. The singulating occurs through the grooves having solder printed therein, and results in wettable upper and sidewall surfaces of the outer ends of the leadframe for each package.
Public/Granted literature
- US20200013634A1 METHOD FOR CREATING A WETTABLE SURFACE FOR IMPROVED RELIABILITY IN QFN PACKAGES Public/Granted day:2020-01-09
Information query
IPC分类: