Process for the production of entry sheet for drilling and use thereof
US7641934B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 2007 |
| Grant date | Jan 5, 2010 |
| Priority date | — |
| Expiry date | Jul 9, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/265
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
There are provided a process for the production of an entry sheet for drilling, comprising preparing a water-soluble resin composition solution by using a mixed solvent containing water and isopropyl alcohol in a specific ratio as a solvent of a water-soluble resin composition, then applying the solution to a sheet-like base material and drying the resultant base material to form a resin layer on the base material, and a method of drilling a printed wiring board material using the above entry sheet. According to the present invention, the problems of remaining bubbles in the resin layer and a decrease in surface flatness and smoothness due to the occurrence of a ridge, which are caused because the melting point of the water-soluble resin is lower than the boiling point of water, are overcome, and an entry sheet for drilling excellent in hole position accuracy is provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.