The present invention relates generally to circuit protection apparatuses and methods for making circuit protection apparatuses. More particularly, the present invention relates to circuit protection apparatuses and methods for making the same, where the circuit protection apparatuses include electrical transient material, such as voltage variable material (VVM).
Electrical transients produce high electric fields and usually high peak power that can render circuits or the highly sensitive electrical components in the circuits, temporarily or permanently non-functional. Electrical transients can include transient voltages capable of interrupting circuit operation or destroying the circuit outright. Electrical transients may arise, for example, from an electromagnetic pulse, an electrostatic discharge, lightning, a build-up of static electricity or be induced by the operation of other electronic or electrical components. An electrical transient can rise to its maximum amplitude in sub-nanosecond to microsecond times and have repeating amplitude peaks.
Materials exist for the protection against electrical transients, which are designed to respond very rapidly (ideally before the transient wave reaches its peak) to reduce the transmitted voltage to a much lower value for the duration of the electrical transients. Electrical transient materials are characterized by high electrical resistance values at low or normal operating voltages. In response to an electrical transient, the materials switch very rapidly to a low electrical resistance state. When the electrical transient dissipates, these materials return to their high resistance state. Electrical transient materials also recover very rapidly to their original high resistance value upon dissipation of the electrical transient.
Circuits, devices and apparatuses, such as a surge protection device, employing electrical transient materials can shunt a portion of the excessive voltage or current due to the electrical transient to ground, protecting the electrical circuit and its components. VVM may be used as electrical transient material in conventional circuit protection devices. Conventional VVM's have typically been of a consistency and composition requiring some form of housing or encapsulation that covers the VVM. This housing or encapsulation is used to prevent malfunction of the VVM, which may be caused by ambient moisture and/or contaminants (e.g., dust). However, use of the housing or encapsulation increases the cost of manufacturing conventional surge protection devices that use VVM. Furthermore, the housing or encapsulation may constrain manufacturing of miniaturized surge protection devices that use VVM.
Other problems with conventional surge protection devices will become apparent in view of the disclosure below.
Circuit protection devices and apparatuses that employ structurally resilient electrical transient material are disclosed. Methods for providing such circuit protection devices and apparatuses are also disclosed. In some implementations, the structurally resilient electrical transient material is a structurally resilient voltage variable material (VVM).
In some implementations, an apparatus may include a support structure, and an electrical transient material at least partially covering the support structure to thereby provide the support structure at least partially integrated in the electrical transient material.
In further implementations, a method may include providing a support structure, and at least partially covering the support structure with an electrical transient material to thereby provide the support structure at least partially integrated in the electrical transient material.
In yet further implementations, a circuit protection apparatus may include a support structure, an electrical transient material at least partially covering the support structure to thereby provide the support structure at least partially integrated in the electrical transient material, a first electrically conductive layer disposed over a first surface of the electrical transient material, and a second electrically conductive layer disposed over a second surface of the electrical transient material.
Circuit protection devices and apparatuses that employ structurally resilient electrical transient material are disclosed herein. Furthermore, methods to provide circuit protection devices and apparatuses that employ structurally resilient electrical transient material are disclosed herein. In some implementations, circuit protection devices and apparatuses employ structurally resilient electrical transient material that includes a support structure that is at least partially covered by an electrical transient material. In some implementations, the electrical transient material includes a binder material. The binder material may include therein a mixture of conductive and semi conductive particles. Furthermore, the binder material may include therein a mixture of insulative particles or nonconductive particles. In another example, the electrical transient material includes a binder material that comprises conductive and semi conductive particles. At least some of the conductive and semi conductive particles may be coated with an insulative oxide film.
In some implementations, the electrical transient material is a voltage variable material (VVM). In one example, the VVM includes an epoxy or resin material. The epoxy resin material may be a polymer-based material. The epoxy resin material may include particles. The particles may include: conductive particles (including core and shell conductive particles), insulating particles, semiconductive particles, doped semiconductive particles (including core and shell doped semiconductive particles) and any combination thereof.
The VVM may at least partially cover the support structure. In one example, the support structure is a mesh or lattice material. In another example, the support structure is at least one spacer material that includes a plurality of through holes, apertures, or through ways. In another example, the support structure is a plurality of single hole spacers. The holes or through ways of the aforementioned support structures may be square shaped, circular shaped, rectangle shaped, tetrahedral shaped, pyramidal shaped, triangular shaped, hexagon shaped, or the like.
The support structure 104 may be an electrically nonconductive material. For example, the support structure 104 may be glass, Kevlar, polymer, ceramic, carbon fiber, insulated metal, nonconductive material, fabric, or the like. Similarly, as discussed in the foregoing, the support structure 104 may comprise at least one spacer material (see
The strands 106 of the support structure 104 may have a diameter of approximately 6 μm. However, the diameter of the strands 106 may be less than or greater than 6 μm. For example, the diameter of the strands 106 may be 1 mil. Alternatively, the diameter of the strands 106 may be 0.6 mil. The apertures 108 of the support structure 104 may have a width and/or length of at least 115 μm. In one example, at least one of the apertures 108 is defined by an opening of 115×145 μm. The size of the apertures 108 may be less than or greater than 115 μm. In one particular implementation, the support structure 104 has a material free open area of approximately 55% and a thermal stability of approximately 250° C. In some implementations, the free open area is between 1-95%. In addition, in some implementations, the support structure 104 is thermally stable at least up to a hardening temperature of the electrical transient material 102. Therefore, in one implementation, the support structure 104 resists melting, softening, and the like up to approximately 250° C. In one implementation, the support structure 104 is inert to organic solvents. Furthermore, the support structure 104 may have a compression strength capable of tolerating a force of approximately 150 kg/cm2. In particular, the support structure 104 may be structurally stable up to at least a force of approximately 150 kg/cm2. Therefore, the support structure 104 resists cracking, breaking, deformation, or the like up to at least a force of approximately 150 kg/cm2. The support structure 104 may have a compression strength capable of tolerating a force of less than or greater than 150 kg/cm2.
In some implementations, the circuit protection apparatus 500 is coupled to the PCB 502 to protect one or more electrical components (not illustrated) associated with the PCB 502 from transient voltages capable of interrupting circuit operation or destroying the one or more electrical components. To that end, the structurally resilient electrical transient material 100 has a high electrical resistance value at low or normal operating voltages associated with the PCB 502. However, the structurally resilient electrical transient material 100 is functional to switch very rapidly to a low electrical resistance state when a transient voltage occurs. Therefore, the circuit protection apparatus 500 may be implemented on the PCB 502 in a manner that shunts transient voltages to ground, thereby protecting the one or more electrical components associated with the PCB 502.
In some implementations, the circuit protection apparatus 600 includes a first via 610 and a via 612. Cu may be disposed in the via 610. The Cu disposed in the via 610 is electrically coupled to the second electrode 608. Similarly, Cu may be disposed in the via 612. The Cu disposed in the via 612 is electrically coupled to the first electrode 606. Cu layers 614 and 616 may be disposed on a surface of the substrate 602. Similarly, Cu layers 618 and 620 may be disposed on a surface of the substrate 604. The layers and 614 and 618 may be electrically coupled by the Cu disposed in the via 610. Similarly, the layers 616 and 620 may be electrically coupled by the Cu disposed in the via 612. Tu 622 may be applied to the layers 614-620.
In some implementations, the circuit protection apparatus 600 may protect one or more electrical components (not illustrated) from transient voltages capable of interrupting circuit operation or destroying the one or more electrical components. To that end, the structurally resilient electrical transient material 100 has a high electrical resistance value at low or normal operating voltages. However, the structurally resilient electrical transient material 100 is functional to switch very rapidly to a low electrical resistance state when a transient voltage occurs. Therefore, the circuit protection apparatus 600 may be implemented on a PCB or the like in a manner that shunts transient voltages to ground, thereby protecting the one or more electrical components associated with the PCB.
At block 704, a support structure is provided. In one example, the support structure is a mesh or lattice material. In another example, the support structure is at least one spacer material that includes a plurality of through holes, apertures, or through ways. In another example, the support structure is a plurality of single hole spacers. The holes or through ways of the aforementioned support structure materials may be square shaped, circular shaped, rectangle shaped, tetrahedral shaped, pyramidal shaped, triangular shaped, hexagon shaped, or the like. The support structure may be an electrically nonconductive material. For example, the support structure may be glass, Kevlar, polymer, ceramic, carbon fiber, insulated metal, nonconductive material, fabric, or the like. In one example, one or more of the strands (e.g., strands 106) of the support structure may comprise electrically nonconductive material. Similarly, as discussed in the foregoing, the support structure may comprise at least one spacer material (see
The strands 106 of the support structure 104 may have a diameter of approximately 6 μm. However, the diameter of the strands 106 may be less than or greater than 6 μm. For example, the diameter of the strands 106 may be 1 mil. Alternatively, the diameter of the strands 106 may be 0.6 mil. The apertures of the support structure may have a width and/or length of at least 115 μm. In one example, at least one of the apertures is defined by an opening of 115×145 μm. The size of the apertures may be less than or greater than 115 μm. In one particular implementation, the support structure has a material free open area of approximately 55% and a thermal stability of approximately 250° C. In some implementations, the free open area is between 1-95%. In addition, in some implementations, the support structure 104 is thermally stable at least up to a hardening temperature of the electrical transient material 102. In one implementation, the support structure is inert to organic solvents. Furthermore, support the structure may have a compression strength capable of tolerating a force of approximately 150 kg/cm2. The support structure may have a compression strength capable of tolerating a force of less than or greater than 150 kg/cm2.
At block 706, the electrical transient material and the support structure are combined. In one example, combining the electrical transient material and the support structure provides at least a partially integrated structure that includes the electrical transient material and the support structure in the electrical transient material. In one embodiment, the support structure is placed on a rigid surface, such as a conductive substrate or a plate, and the electrical transient material is applied over the support structure. Electrical transient material in powdered form may be sprayed over the support structure. Electrical transient material in ink form may also be sprayed over the support structure. Alternatively, electrical transient material in ink form may be applied over the support structure using an application blade. Electrical transient material in powdered form may be combined with the support structure by way of compression using a press or roll press to achieve a desired thickness of the structurally supported electrical transient material. Electrical transient material in ink form may be combined with the support structure using an application blade (e.g., Doctor Blade) to achieve a desired thickness of the structurally supported electrical transient material. In one or more embodiments, the process of combining the electrical transient material and the support structure may include providing one or more electrically conductive surface over a surface or surfaces of the structurally supported electrical transient material.
At block 708, the combined electrical transient material and support structure, which provide the structurally supported electrical transient material, is allowed to harden by drying, if necessary as part of the process of forming the structurally supported electrical transient material. In one implementation, the combined electrical transient material and support structure are hardened in an oven.
While structurally enhanced/supported electrical transient material and a method for manufacturing structurally enhanced/supported electrical transient material have been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the claims of the application. Other modifications may be made to adapt a particular situation or material to the teachings disclosed above without departing from the scope of the claims. Therefore, the claims should not be construed as being limited to any one of the particular embodiments disclosed, but to any embodiments that fall within the scope of the claims.
Filing Document | Filing Date | Country | Kind |
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PCT/CN2017/078955 | 3/31/2017 | WO | 00 |