Diffusion patterned C4 bump pads
US5924623A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 30, 1997 |
| Grant date | Jul 20, 1999 |
| Priority date | — |
| Expiry date | Jun 30, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/3452
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A development process of C4 bump pads is for advanced microelectronic integrated circuit connection technology. This approach involves the laying down of conductor lines on a substrate and an encapsulation over the lines, plus the making of openings for making the bump pads. The bump pads are for situating solder balls for connections with a flip chip or integrated circuit. The openings are made by application of a diffusing material that is patterned on the glass encapsulation to define the areas of the bump pads. After the material is dried and diffused into the encapsulation layer, the diffused material is washed out with water to leave open areas for the bump pads. Then solder balls may be placed on the bump pads and heated to adhere to the conductor lines and form rounded bumps on the respective pads. Flux may then be applied to the solder bumps, and the flip chip is placed with its terminals on the solder bumps which are heated for connection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.