Method and installation for fracturing a composite substrate along an embrittlement plane
View Patent ↗A method of fracturing a composite structure along an embrittlement plane defined between two layers by producing a fracture in the structure along the embrittlement plane. During fracturing, the composite structure is disposed in a boat housing and held in contact against stiffeners disposed on both sides of the structure and aligned parallel to each other. Each stiffener has a diameter that is at least 40% to 300% of the diameter of the composite structure to be fractured.
1. A method of fracturing a composite structure along an embrittlement plane defined between two substrates, which comprises:
disposing stiffeners on both sides of the composite structure and spaced from it,
adjusting the spacing between the stiffeners and composite structure so that, during a subsequent fracturing step, the composite structure and the stiffeners on both sides of that structure are separated by a cumulative spacing that is greater than zero but less than 500 micrometers,
determining the cumulative spacing between the stiffeners and the composite structure to be adjusted according to the diameter of the composite structure and the difference in the thermal expansion coefficient between the substrates making up the structure, and
fracturing the composite structure along the embrittlement plane by thermal annealing while the structure is held between the stiffeners so that released energy is damped by stiffeners in held contact with the composite structure such that any shock waves are absorbed.
2. The method according to claim 1 , wherein each stiffener has a diameter that is at least 40% to 300% of the diameter of the composite structure.
3. The method according to claim 1 , wherein each stiffener has a diameter that is at least 50% to 200% of the diameter of the composite structure.
4. The method according to claim 1 , wherein each stiffener has a diameter that is 50%±5% or 95%±10% of the diameter of the composite structure.
5. The method according to claim 1 , which further comprises disposing the composite structure substantially vertically during the fracturing.
6. The method according to claim 1 , which further comprises disposing the composite structure substantially horizontally during the fracturing.
7. The method according to claim 1 , which further comprises forming the embrittlement plane of the composite structure by implantation of ions.
8. The method according to claim 1 , wherein the composite structure includes two substrates having different thermal expansion coefficients.
9. The method according to claim 1 , which further comprises making the composite structure by assembling two substrates against each other, wherein one of the substrates includes the embrittlement plane.
10. The method of claim 1 , wherein the thermal annealing is conducted in a housing for a thermal annealing installation boat, wherein the housing is configured to receive the composite structure to be fractured.
11. The method according to claim 1 , in which the stiffening elements are aligned parallel to each other.
12. The method according to claim 1 , wherein
the thermal annealing is conducted in an installation comprising a furnace, a boat able to receive a plurality of composite structures, and a housing with each composite structure located between a spaced apart pair of stiffeners.