Direct chip attach structure and method
US6835580B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 2003 |
| Grant date | Dec 28, 2004 |
| Priority date | — |
| Expiry date | Jun 26, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/13091
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for forming a direct chip attach (DCA) device (1) includes attaching a chip (3) to a lead frame (2). Conductive studs (22) are attached to bonding pads (13) on the chip (3) and a flag (18) on lead frame (2). The chip (3) and flag (18) are enclosed with an encapsulating layer (4), and openings (6) are formed in an upper surface (7) to expose conductive studs (22). In one embodiment, a masking layer (51) is applied to the lead frame (2), and the structure is then placed in an electroless plating apparatus (61). While in the plating apparatus (61), an injection device (66) injects plating solution (71) towards the upper surface (7) and openings (6) to enhance the formation of barrier layers (24) on the conductive studs (22). Solder bumps (9) are then attached to barrier layers (24) through the openings (6).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.