Method for fabricating an electronic device and a stacked electronic device
A method for fabricating an electronic device includes fixing a rear face of an integrated-circuit chip to a front face of a support wafer. An infused adhesive is applied in the form of drops or segments that are separated from each other. A protective wafer is applied to the infused adhesive, and the infused adhesive is cured. The infused adhesive includes a curable adhesive and solid spacer elements infused in the curable adhesive. A closed intermediate peripheral ring is deposited on the integrated-circuit chip outside the cured infused adhesive, and an encapsulation block is formed such that it surrounds the chip, the protective wafer and the closed intermediate peripheral ring.
1. A method, comprising:
fixing a rear face of an integrated-circuit chip to a front face of a support wafer;
depositing on a front face of the integrated-circuit chip an infused adhesive in a form of drops or segments at a distance from one another and positioned outside a central region of the front face of the integrated-circuit chip, the infused adhesive comprising a curable adhesive and solid spacer elements infused in the curable adhesive;
placing a protective wafer on the infused adhesive so that a free space remains between the front face of the integrated-circuit chip and a rear face of the protective wafer;
curing the curable adhesive to fix the protective wafer to the integrated-circuit chip;
producing an intermediate peripheral ring between the front face of the integrated-circuit chip and the rear face of the protective wafer after curing the curable adhesive; and
producing an encapsulation ring around the integrated-circuit chip, the protective wafer, and the intermediate peripheral ring on a peripheral zone of the front face of the support wafer.
2. The method of claim 1 , wherein producing the intermediate peripheral ring comprises curing a resin using ultraviolet radiation without releasing gas.
3. The method of claim 1 , wherein producing the encapsulating ring comprises supplying a coating material and curing the coating material.
4. The method of claim 1 , wherein curing the curable adhesive comprises heating to polymerize the curable adhesive and releasing gas.
5. The method of claim 1 , wherein producing the encapsulation ring comprises applying a liquid material in an area which surrounds a stack formed by the integrated-circuit chip and the protective wafer.
6. The method of claim 5 , further comprising curing the liquid material and dicing the support wafer and the cured liquid material to form an electronic device.
7. The method of claim 1 , wherein the intermediate peripheral ring completely surrounds the free space.
8. The method of claim 1 , wherein the intermediate peripheral ring completely surrounds the protective wafer along a peripheral edge of the protective wafer.
9. The method of claim 8 , wherein the intermediate peripheral ring is produced to be in contact with the peripheral edge of the protective wafer.