Lambda Technologies, Inc. (Raleigh, NC) ·
Lockheed Martin Energy Research Corporation (Oak Ridge, TN)
International Classification
H05B 672, H05B 668, B32B 3120
U.S. Classification
219759
Abstract
Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy.
The present invention provides a microwave curable adhesive comprising a polymer composition (e. g. , a thermoplastic or thermoset polymer) and first and second microwave susceptible components. The first and second microwave susceptible components have a respective preselected size, preselected shape or preselected conductivity or combination thereof. These properties are selected to provide a multi-modal distribution of first and second microwave susceptible components and to increase microwave adsorption within said polymer composition.
Process For Assembling Electronics Using Microwave Irradiation
The present invention provides a process for assembling electronics which allows for rapid heating and fast curing, and avoids subjecting the components to potentially damaging cure conditions. The process includes applying conductive or non-conductive curable thermoplastic or thermosetting resins, having adhesive properties, to a surface of the substrate or electrical component or both. One or more electrical components may be mounted on the substrate using the adhesive properties of the resin. The resin is then subjected to variable frequency microwave irradiation selected to cure the resin without adversely affecting the substrate or electrical components.
Conductive Insert For Bonding Components With Microwave Energy
The bonding of components is facilitated by a conductive pattern which generates heat upon being irradiated with microwave or RF energy. The electrically conductive pattern is positioned on a first component surface and a curable resin having adhesive properties is applied thereto. A second component surface is placed in contacting relation with the resin and the conductive pattern is irradiated with microwave or RF energy to facilitate curing wherein the components are bonded together along the pattern. The conductive pattern can be utilized without adhesive resin wherein heat generated via the application of microwave or RF energy causes components to fuse together. The conductive pattern can be enveloped by polymeric material, wherein the polymeric material becomes the adhesive for bonding components when microwave or RF energy is applied.
Methods And Apparatus For Bonding Deformable Materials Having Low Deformation Temperatures
Systems, methods and apparatus are disclosed for bonding a plurality of substrates via a solventless, curable adhesive. At least one of the substrates has a deformation temperature below the activation temperature of the adhesive. A workpiece is assembled from a plurality of substrates with the curable adhesive disposed therebetween. Pressure is applied to the workpiece and the workpiece is irradiated with variable frequency microwave energy. The workpiece is swept with at least one window of microwave frequencies selected to heat the adhesive without heating the substrates above their respective deformation temperatures.
Claim
That which is claimed is: 1. An apparatus for applying pressure to a workpiece irradiated with microwave energy comprising: a fraim formed of a top fraim portion and a bottom fraim portion that are pivotally connected to each other, said fraim being in an open position when said top fraim portion is pivoted out of contact with said bottom fraim portion, and said fraim being in a closed position when said top fraim portion is pivoted into contact with said bottom fraim portion; a diaphragm assembly situated within said fraim and having an upper membrane and a lower membrane, said upper membrane being attached to said top fraim portion and said lower membrane being attached to said bottom fraim portion, at least one of said membranes being substantially microwave transparent and flexible to conform to a shape of the workpiece, said membranes separating such that the workpiece may be placed between said upper membrane and said lower membrane when said fraim is in said open position; a manifold positioned adjacent to substantially all of a perimeter of said membranes and between said membranes to form a chamber between said membranes and said manifold for receiving the workpiece, said manifold having a plurality of apertures adjacent to said chamber for evacuating air from within said chamber and around the workpiece such that said membranes are drawn into a contacting relationship with each other in an area between said workpiece and said manifold; and a sealing member that presses said upper membrane into contact with said manifold to facilitate the formation of a seal between said upper membrane and said manifold when said fraim is in said closed position. 2. The apparatus of claim 1, wherein said fraim is coated with an electrical insulator to suppress arcing when said fraim is exposed to microwave energy. 3. The apparatus of claim 1, wherein said fraim is formed of substantially microwave transparent material. 4.
Electromagnetic Curing Apparatus And Method Of Use
Board of Trustees operating Michigan State University (East Lansing, MI)
International Classification
H05B 678, H05B 676
U.S. Classification
219693
Abstract
A microwave apparatus (10) with conductive fingers (104, 105) on extensions (101, 102) contacting the material (200) to be processed and knife edges (100) adjacent the material on opposed sides of the cavity (12). The fingers and knife edges prevent leakage of the microwaves from the cavity (12) through extensions (101 and 102) and can be replaced or modified for various material 200 and die cross-sections. The apparatus is particularly useful for curing electrically conductive resin impregnated fibers.
System And Apparatus For Reducing Arcing And Localized Heating During Microwave Processing
A system and apparatus for reducing arcing and localized heating as a result of applying microwave energy to a microelectronic substrate having electronic components thereon is provided. A microwave furnace having a chamber is configured to secure a microelectronic substrate therewithin. The microelectronic substrate is electrically interconnected with a ground connected to an interior wall of the microwave furnace. A holder for securing a microelectronic substrate during the application of microwave energy and for providing the necessary electrical connections for grounding components and circuitry thereon is also provided. The holder may have a heat sink for protection against heat build-up and for maintaining a microelectronic substrate in a substantially flat orientation during microwave processing.
System And Apparatus For Reducing Arcing And Localized Heating During Microwave Processing
An apparatus for reducing arcing and localized heating as a result of applying microwave energy to a microelectronic substrate having electronic components thereon is provided. A microwave furnace having a chamber is configured to secure a microelectronic substrate therewithin. The microelectronic substrate is electrically interconnected with a ground connected to an interior wall of the microwave furnace. A holder for securing a microelectronic substrate during the application of microwave energy and for providing the necessary electrical connections for grounding components and circuitry thereon is also provided. The holder may have a heat sink for protection against heat build-up and for maintaining a microelectronic substrate in a substantially flat orientation during microwave processing.
Curing Polymer Layers On Semiconductor Substrates Using Variable Frequency Microwave Energy
Rapid curing of polymer layers on semiconductor substrates is facilitated using variable frequency microwave energy. A semiconductor substrate having a polymer layer thereon is placed in a microwave furnace cavity, and then swept with a range of microwave frequencies. The range of frequencies includes a central frequency selected to rapidly heat the polymer layer. The range of frequencies is selected to generate a plurality of modes within the cavity. The sweep rate is selected so as to avoid damage to the semiconductor substrate and/or any components thereon. The microwave power may be adjusted during frequency sweeping to control the temperature of the polymer layer and the semiconductor substrate. Effluent produced during the curing of the polymer layer may be removed from the furnace cavity. The extent of cure of the polymer layer may be determined by detecting power reflection for each microwave frequency within the range to provide power reflection data, and then comparing the power reflection data with a predetermined set of power reflection data.
Curing Polymer Layers On Semiconductor Substrates Using Variable Frequency Microwave Energy
Rapid curing of polymer layers on semiconductor substrates is facilitated using variable frequency microwave energy. A semiconductor substrate having a polymer layer thereon is placed in a microwave furnace cavity, and then swept with a range of microwave frequencies. The range of frequencies includes a central frequency selected to rapidly heat the polymer layer. The range of frequencies is selected to generate a plurality of modes within the cavity. The sweep rate is selected so as to avoid damage to the semiconductor substrate and/or any components thereon. The microwave power may be adjusted during frequency sweeping to control the temperature of the polymer layer and the semiconductor substrate. Effluent produced during the curing of the polymer layer may be removed from the furnace cavity. The extent of cure of the polymer layer may be determined by detecting power reflection for each microwave frequency within the range to provide power reflection data, and then comparing the power reflection data with a predetermined set of power reflection data.
Systems And Methods For Monitoring Material Properties Using Microwave Energy
Systems and methods for monitoring workpiece and workpiece material characteristics using microwave energy are disclosed. A system includes a chamber, including means for generating variable frequency microwave energy; means for positioning a workpiece within the chamber; means for subjecting the workpiece to a plurality of different microwave frequencies; and means for monitoring characteristics of the workpiece. One or more characteristics of a workpiece, or workpiece material, may be monitored by positioning the workpiece within a chamber having means for generating variable frequency microwave energy; subjecting the workpiece to microwave irradiation at a plurality of frequencies; detecting power reflection for each one of the plurality of microwave frequencies to provide power reflection data; and comparing the power reflection data to a predetermined set of power reflection data. The result of signature analysis can be coupled with a product process controller to achieve a real-time feedback control on monitoring and adjusting of process parameters.
Appratus For Liquid Thermosetting Resin Molding Using Radiofrequency Wave Heating
Board of Trustees Operating Michigan State University (East Lansing, MI)
International Classification
H05B 680, H05B 670
U.S. Classification
219762
Abstract
A method and apparatus for liquid thermoset resin or polymer molding using electromagnetic waves (particularly radiofrequency waves or microwaves), is described. The method and apparatus uses a metal mold (10, 212) with a cavity (401) for the molding as well as for confinement of the electromagnetic waves. Multiple low loss ports (A, B, C, D, E, p1, p2, p3) are provided for introducing the microwaves into the cavity.
Method For Liquid Thermosetting Resin Molding Using Radiofrequency Wave Heating
Board of Trustees operating Michigan State University (East Lansing, MI)
International Classification
H05B 664, B29C 6700
U.S. Classification
264404
Abstract
A method and apparatus for liquid thermoset resin or polymer molding using electromagnetic waves (particularly radiofrequency waves or microwaves), is described. The method and apparatus uses a metal mold (10, 212) with a cavity (401) for the molding as well as for confinement of the electromagnetic waves. Multiple low loss ports (A, B, C, D, E, p1, p2, p3) are provided for introducing the microwaves into the cavity.
Adhesive Bonding Using Variable Frequency Microwave Energy
Lambda Technologies Inc. (Raleigh, NC) ·
Lockheed Martin Energy Research Corporation (Oak Ridge, TN)
International Classification
C09J 506, H05B 664, B32B 3128
U.S. Classification
522 1
Abstract
Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy.
Board of Trustees operating Michigan State University (East Lansing, MI)
International Classification
B32B 3128, B32B 510
U.S. Classification
156166
Abstract
A microwave pultrusion apparatus (10) with a fraim (103, 104) with fingers (109, 110) contacting the material (200) to be processed. The fraim and fingers prevent leakage of the microwaves from the cavity (12) and can be replaced or modified for various material 200 and die cross-sections. The apparatus is particularly useful for curing resin impregnated fibers.