Enhanced copper posts for wafer level chip scale packaging
US7932601B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 2010 |
| Grant date | Apr 26, 2011 |
| Priority date | — |
| Expiry date | Oct 6, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/181
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An enhanced wafer level chip scale packaging (WLCSP) copper electrode post is described having one or more pins that protrude from the top of the electrode post. When the solder ball is soldered onto the post, the pins are encapsulated within the solder material. The pins not only add shear strength to the soldered joint between the solder ball and the electrode post but also create a more reliable electrical connection due to the increased surface area between the electrode post/pin combination and the solder ball. Moreover, creating an irregularly shaped solder joint retards the propagation of cracks that may form in the intermetal compounds (IMC) layer formed at the solder joint.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.