Printed circuit board having epoxy barrier around a throughout slot and ball grid array semiconductor package
US5767446A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Oct 24, 1996 |
| Grant date | Jun 16, 1998 |
| Priority date | — |
| Expiry date | Oct 24, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/351
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A printed circuit board (PCB) having an epoxy barrier disposed around its throughout slot in a semiconductor chip mounting region, and a BGA semiconductor package using such a PCB, thereby exhibiting a high moisture discharge characteristic. The epoxy barrier includes a copper layer and a solder resist layer both disposed around the throughout slot and is defined by a groove which is disposed around the throughout slot while spacing apart from the periphery of the throughout slot by a desired distance. Alternatively, the epoxy barrier includes a solder resist layer formed to a desired width around the throughout slot on the uppermost layer laminated on the PCB. By virtue of the epoxy barrier, the throughout slot is not closed by epoxy resin coated over the PCB. As a result, it is possible to externally discharge moisture which expands in the PCB upon carrying out a series of processes for the fabrication of the package at a high temperature or mounting the package on a mother board. Accordingly, it is possible to eliminate interface peeling-off and formation of cracks. This results in an improvement in reliance of final products.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.