Method of cleaving a brittle material using a point heat source for providing a thermal stress
US6023039A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 29, 1997 |
| Grant date | Feb 8, 2000 |
| Priority date | — |
| Expiry date | Oct 29, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T225/304
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method of cleaving a strip by tensile stress applied by a pulse laser point heat source by shifting a pulse-heating position of the pulse laser point heat source on the basis of both an optimum distance "D" of a center position of a pulse beam spot of the pulse laser point heat source irradiated on the strip from a tip of a crack of the strip and an optimum pulse time "t" of the pulse laser point heat source, wherein the optimum distance "D" is determined by the steps of: selecting "t" to find a value of 4.kappa.t/W.sup.2 where ".kappa." is a thermal diffusivity of the strip, "W" is a width defined as a distance between a cleaving-intended line and a side edge of the strip; and finding an optimum value of D/W from the value of 4.kappa.t/W.sup.2 with reference to a previously obtained relationship between the optimum value of D/W and the value of 4.kappa.t/W.sup.2 thereby to find the optimum distance "D". The optimum distance "D" is found so that if the value of 4.kappa.t/W.sup.2 is in the range of 0.0001-0.05, then the optimum value of D/W is 0.1, if the value of 4.kappa.t/W.sup.2 is in the range of 0.05-1.0, then the optimum value of D/W is 0.2, and if the value of 4.kappa.t/W.s…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.