초록 ▼

A method for encapsulating an electrical component or forming a resin based filler reinforced composite article which comprises providing a rigid mold having a cavity and an opening in one surface of the mold connected to the cavity, and a chamber in which the mold is placed for applying heat and va

A method for encapsulating an electrical component or forming a resin based filler reinforced composite article which comprises providing a rigid mold having a cavity and an opening in one surface of the mold connected to the cavity, and a chamber in which the mold is placed for applying heat and varying pressure to the mold contents. The chamber is preheated to the curing temperature of the resin and is maintained at this temperature. The component or filler is loaded into the mold cavity and the mold is placed in the preheated chamber. Then the mold cavity is filled with a low viscosity heat curable, thermosetting resin such as an epoxy resin. Next, the mold cavity is evacuated to a subatmospheric pressure to impose a vacuum on the mold to impregnate the component or filler with the resin, degas the mold cavity contents, and expand any voids in the resin. The vacuum is released to atmospheric pressure to collapse any gas bubbles remaining in the mold contents. Then, a superatmospheric pressure is applied to the mold to burst any gas bubbles and cause the resin to compact and encapsulate the component or filler. The temperature and the superatmospheric pressure are maintained for a time sufficient to partially cure the resin and form a unitary structure which can be ejected from the mold. The ejected structure is then subjected to further heating to completely cure the resin. The method may be performed in cyclic fashion to form continuously in sequence a plurality of encapsulated components or composite articles. Composite articles so formed are useful as structures, such as antenna waveguides, for space applications. Electrical components encapsulated by the process of the present invention have high voltage resistance.

대표청구항 ▼

A method for forming a resin based filler reinforced composite article which comprises the steps of: (a) providing a rigid mold having a cavity therein and an opening in one surface of said mold and communicating with said cavity; (b) providing a chamber for containing said mold and for applying hea

A method for forming a resin based filler reinforced composite article which comprises the steps of: (a) providing a rigid mold having a cavity therein and an opening in one surface of said mold and communicating with said cavity; (b) providing a chamber for containing said mold and for applying heat and varying pressures to said cavity of said mold; (c) heating said chamber to a predetermined temperature and maintaining said temperature in said chamber; (d) loading a quantity of a particulate filler material in said cavity of said mold; (e) loading said mold containing said filler into said heated chamber; (f) filling the mold cavity with a low viscosity heat curable themosetting resin which cures at said predetermined temperature; (g) evacuating the mold cavity to a subatmospheric pressure within the range of about 1 to 200 millimeters of mercury for about 1 to 5 minutes, to impose a vacuum on the mold to thereby impregnate the filler material with the resin, degas the mold contents, and expand any remaining voids in the resin; (h) releasing the vacuum to atmospheric pressure to collapse any gas bubbles remaining in the mold contents; (i) applying a superatmospheric pressure within the range of about 100, to 1000 pounds per square inch (about 6.90×105 to 6.90×106 pascals) for about 1 to 2 hours, to the mold to burst any said gas bubbles and cause the heat curable resin to compact and encapsulate particles of the filler loaded in the mold, the temperature and the superatmospheric pressure being maintained for a time sufficient to partially cure the resin and form a unitary structure; (j) ejecting the structure from the mold cavity; and (k) subjecting the ejected structure to a further heating cycle to completely cure the resin. A method for encapsulating an electrical component which comprises the steps of: (a) providing a rigid mold having a cavity therein and an opening in one surface of said mold and communicating with said cavity; (b) providing a chamber for containing said mold and for applying heat and varying pressures to said cavity of said mold; (c) heating said chamber to a predetermined temperature and maintaining said temperature in said chamber; (d) loading the component in said cavity of said mold; (e) loading said mold containing said component into said heated chamber; (f) filling the mold cavity with a low viscosity heat curable thermosetting resin which cures at said predetermined temperature; (g) evacuating the mold cavity to a subatmospheric pressure within the range of about 1 to 4 millimeters of mercury for about 1 to 5 minutes, to impose a vacuum on the mold to thereby impregnate the component with the resin, degas the mold contents, and expand any remaining voids in the resin; (h) releasing the vacuum to atmospheric pressure to collapse any gas bubbles remaining in the mold contents; (i) applying a superatmospheric pressure within the range of about 50 to 100 pounds per square inch (about 3.45×105 to 6.90×105 pascals) for about 30 minutes to 3 hours, to the mold to burst any said gas bubbles and cause the heat curable resin to encapsulate the component loaded in the mold, the temperature and the superatmospheric pressure being maintained for a time sufficient to partially cure the resin and form a unitary structure; (j) ejecting the structure from the mold cavity; and (k) subjecting the ejected structure to a further heating cycle to completely cure the resin.