TH23977A - The production of airtight cavities in an assembled container and the resulting product by this method. - Google Patents

Abstract

In the container The lid is welded to the base to create a cavity that is impervious to air. For the installation of semiconductor chips in a thermally cured alpha-stage epoxy. The lid has a slender edge inside the base. The base is heated to approximately 95 (formula) 5 ํ. The epoxy is applied on the base to fill the cavity. Free the edge and base when the lid Was placed on the base Very small amounts of epoxy seep out onto the outer walls of the base rim and the lid is heated to 95 (recipe) 5 ํ in an open oven for about an hour. To incubate the epoxy and then the container The stuffing was cured in an oven at 150 (recipe) 5 ํ for three hours to make it. Epoxy that has been cured and stabilized

Claims (23)

1. The method for creating an airtight cavity in an assembled container when such cavity is defined by a hollow lid covering the base. This method consists of the following steps: a) Applying a heat-curing alpha epoxy gel to the pre-defined area of the base to create the cavity; b) Heating the base to a pre-determined temperature; c) Placing the lid on the base so that the edge of the lid rests on the epoxy where it bonds to the pre-heated base; d) Heating and holding the assembled container at an increased temperature for a sufficient period in an open atmosphere to cure the epoxy, thereby sealing the atmosphere in the cavity. The pressure exerted on the epoxy by the expanding atmosphere escaping the cavity counteracts the surface tension of the curing epoxy. Once the epoxy is cured, the cavity is completely airtight, and the cavity is created in an airtight manner; and e) Heating the assembled container to an increased temperature in a closed oven for a sufficient period to further cure and stabilize the cured epoxy. 2. Method under Claim 1, where the base is preheated to an increased temperature before the epoxy is applied. 3. The method under claim 2 includes a procedure to wet the edges of the lid with epoxy before the lid is placed on the base to increase the amount of epoxy between the edge and the base. 4. Method according to Claim 1, when the lid includes a relatively thick protruding edge with a narrow end formed by a recess that tapers onto its inside. When the epoxy is applied to the base in the form of a closed ring, the closed ring matches the closed ring formed by the edge of the lid but is smaller, so that the smaller ring of epoxy fills the gap of the recess. 5. Method according to claim 2: The container was heated to 95(recipe)5°C for approximately one hour initially and then cured in an oven at 150(recipe)10°C for approximately three hours. 6. The assembled containers are manufactured using the method described in Claim 4. 7. A container assembled according to claim 6 where the cavity contains semiconductor chips and where the base is in the form of a conductive wire frame to which the chips on top are bonded and the lid is made of an insulating material. 8. Containers assembled in accordance with claim 7, where the lid is made of a material selected from ceramic and plastic. 9. Containers assembled according to claim 8 where the base is made of a pre-molded conductive wire frame with ceramic substrate or printed circuit board. 10. The container assembled according to claim 6, when the lid includes a relatively thick protruding rim with a narrow end formed by a tapered recess on its inside, epoxy is filled into the tapered recess and the space between the rim and the base, thus the epoxy bonding the rim to the base is firmly attached to the relatively thick base of the rim. Such epoxy forms a rigid wall with the rim and bonds the rim to the base. 11. Containers assembled according to claim 10, where the rigid walls are shaped by epoxy and are firmly bonded to the lid. 12. A container assembled in accordance with claim 11 where the cavity containing the semiconductor chip is designed to operate in gigaherz ranges. 13. Container assembled in accordance with claim 12 when the assembled GaAs chip is a power amplifier. 14. Container assembled in accordance with claim 12 when the assembled GaAs power chip is designed for GDMA applications. 15. Containers assembled in accordance with claim 12 when the MMIC cavity is filled. 16. Container assembled in accordance with claim 12 when the cavity contains the DAS chip. 17. Method for producing an airtight cavity in a constructed container when such cavity is used to contain components such as semiconductor chips, when such cavity is defined by an insulating hollow lid and a conductive wire frame made of a conductive sheet with pre-defined openings drilled from the sheet, the conductive wires are attached to the part. a) Applying a heat-curing alpha epoxy gel onto the conductive wires and over the gaps between the conductive wires in the wire frame in the form of a surrounding wall to form a shape that fits the edge of the lid. When the epoxy viscosity is at a predetermined amount, the surface tension of the epoxy prevents the epoxy from dripping and settling into the openings. b) Placing the lid over the wire frame so that its edge rests on the epoxy wall to form part of the cavity. c) Heating the wire frame and epoxy in an oven at a predetermined increasing temperature for a specified time. The process involves: d) Flipping the wire frame with the welded lid over; e) Heating and treating the wire frame at the specified temperature; f) Applying a heat-curing alpha epoxy layer with the specified viscosity to the preheated wire frame above the cavity opposite the specified area and surrounding it with the lid; g) Heating and treating the container in an open atmosphere at an increasing temperature for a specified period, as the epoxy gains viscosity and its surface tension resists the atmosphere escaping from the cavity through the opening and resists gravity that might cause the epoxy to fall through the opening into the cavity once the epoxy is applied over the opening, once the airtight cavity is created, and once the epoxy hardens to cure; and h) Heating and treating the container in an oven for the specified time at the specified temperature to allow the cured epoxy to set. 18. Method according to claim 17, when the lid includes a relatively thick protruding edge with a narrow end formed by a recess that tapers onto its inside, when the epoxy is applied to the base in the form of a closing ring, when such closing ring matches the closing ring formed by the lid edge but is smaller, so that the smaller ring of epoxy beads fills the gap. 19. Method according to claim 18: The container is heated in an open atmosphere at 95(formula)5°C for approximately one hour and incubation is carried out in a beacon oven at 150(formula)10°C for approximately three hours. 20. Method according to claim 18: When epoxy is applied to the frame, opposite the lid, the application is made covering the entire area enclosed by the lid edge. 21. A container assembled for a semiconductor component manufactured by the method of claim 17, where the lid includes a relatively thick protruding edge with a narrow end formed by a tapered recess on its inside. Epoxy fills the tapered recess between the edge and the conductive wire frame, thus bonding the edge to the base tightly to the relatively thick portion of the base of the edge and forming a thick wall. 22. A container assembled in accordance with claim 21, where the cavity contains a GaAs semiconductor chip designed to operate in the gigahertz range. 23. Container assembled in accordance with claim 21 when the cavity contains MMIC.