Apparatus for applying a sintering force via a compressible film
A sintering apparatus for simultaneously sintering an electronic device onto a substrate, and a metallic sheet onto the electronic device includes a sinter tool and a compressible film positionable onto the metallic sheet and the electronic device. A thickness of the compressible film is greater than a height of the metallic sheet. The compressible film is adapted to conform to a shape of the metallic sheet and the electronic device to simultaneously cover the metallic sheet and at least a part of the electronic device when the sinter tool applies a sintering force onto the compressible film during a sintering process.
1 . Sintering apparatus for simultaneously sintering an electronic device onto a substrate, and a metallic sheet onto the electronic device, the sintering apparatus comprising:
a sinter tool; and
a compressible film positionable onto the metallic sheet and the electronic device, the compressible film comprising a fibrillated membrane expanded at a predetermined stretch ratio to form a porous structure having a lower density than a similar membrane that is unexpanded;
wherein a thickness of the compressible film is greater than a height of the metallic sheet, and the compressible film is adapted to conform to a shape of the metallic sheet and the electronic device to simultaneously cover an exposed area of the metallic sheet and at least a part of an exposed area of the electronic device when the sinter tool applies a sintering force onto the compressible film during a sintering process, and
wherein a volume of the compressible film is configured to change when the sintering force is applied onto the compressible film so as to apply a uniform sintering pressure distribution on the exposed areas of the metallic sheet and the electronic device, which are located at different heights.
2 . Sintering apparatus as claimed in claim 1 , wherein the sintering apparatus is adapted to receive a carrier on which at least one substrate is supportable during sintering, such carrier being configured to fit a piece of the compressible film for covering the metallic sheet and electronic device prior to conducting the sintering process.
3 . Sintering apparatus as claimed in claim 2 , further comprising a compressible film input station for placing the piece of compressible film onto the metallic sheet and electronic device supported by the carrier.
4 . Sintering apparatus as claimed in claim 2 , wherein the carrier has a plurality of pockets, each pocket being configured to hold a respective substrate, and having a through-hole through which a bottom sinter tool may be insertable for supporting the substrate.
5 . Sintering apparatus as claimed in claim 1 , wherein the thickness of the compressible film is sufficient to further cover the metallic sheet and an entire exposed area of the electronic device during the sintering process.
6 . Sintering apparatus as claimed in claim 1 , wherein the compressible material is adapted to conform to and cover a bottom surface and parts of the sidewalls of the sinter tool when the sinter tool is applying a sintering force onto it during the sintering process.
7 . Sintering apparatus as claimed in claim 1 , wherein the compressible film comprises expanded PTFE.
8 . Sintering apparatus as claimed in claim 7 , wherein the expanded PTFE has a density of 0.5 to 0.9 g/cm 3 and a compressibility of 50 to 90%.
9 . Sintering apparatus as claimed in claim 8 , wherein the expanded PTFE further has a specific gravity of 0.1 to 1.9 g/cm 3 and a porosity of 25 to 96%.
10 . Sintering apparatus as claimed in claim 1 , wherein the compressible film comprises expanded graphite film.
11 . Sintering apparatus as claimed in claim 10 , wherein the expanded graphite film has a density of 0.5 to 1.5 g/cm 3 and a compressibility of 15 to 70%.
12 . Sintering apparatus as claimed in claim 1 , wherein the compressible film comprises multiple separate conformable layers of compressible film.