MXPA00002842A - Core and coil structure and method of making the same - Google Patents

Abstract

An inductive device is comprised of a plurality of dielectric wafers (100) having conductive patterns (126) disposed thereon and being formed into a laminate structure. The laminate structure includes a ferromagnetic core (124) encased within the dielectric material (104). The conductive patterns (126) are interconnected using vias (122) to create a conductive structure, such as windings, about the core. During fabrication of the device, the core is pressurized to maintain high-permeability characteristics. As a result, inductive devices such as transformers and inductors can be made having small dimensions and high inductive values.

Description

STRUCTURE OF NUCLEUS AND COIL AND METHOD TO MANUFACTURE THE SAME BACKGROUND OF THE INVENTION FIELD OF THE INVENTION This invention relates generally to induction devices, and in particular to a multilayer laminated induction device and to a method for manufacturing same.

DESCRIPTION OF THE PREVIOUS TECHNIQUE The microcircuits and older designers avoided the induction components of surface mounting as transformers and inductors due to the relatively large physical size of such devices. Eventually, micro size induction components were developed, however, those components showed extremely low inductance values (for example from nano Henrys to a Henry micro). As a result, they could only be used at high frequencies, such as for microwave frequency circuits. A conventional solution, as illustrated in the patent of E.U.A. 3,765,082 to Zytez, tried to overcome these problems using a monolithic inductor chip. However, the coil design in said conventional solutions is inefficient and is unable to obtain such high induction levels as the present invention, because it only uses ferrite disks to form the laminated structure. As a result, highly permeable ferrite was not generally used, since it tends to short circuit the conduction lines (eg windings) of the device.

BRIEF DESCRIPTION OF THE INVENTION Accordingly, there has been a much felt need in the art for an inductor, transformer or other small size induction device having a high permeability core, which can be used in a wide range of frequency applications. In certain embodiments of the invention, the invention facilitates the construction of devices having relatively large permeability values and small physical size, and which are capable of operating at high energy levels within frequency ranges from low to microwave. In certain embodiments, the devices according to the invention are provided with dimensions of approximately 1.27 to 2.54 cm per side and 1270-1524 microns in thickness while maintaining a high level of inductance, such as, for example, 20mH. In another embodiment, the device can be provided with dimensions of approximately 2540 by 3048 microns with a similar thickness, while maintaining a high level of inductance, such as, for example, 100mH. In yet another embodiment, the device may be provided with measurements of approximately 1016 by 508 microns with a similar thickness, while maintaining a high level of inductance, such as, for example, 1 to 10mH. One aspect of the present invention is the unique winding and dimensioning of the inductor coil as to maximize the magnetic properties of the ferromagnetic materials being used. Another aspect of the present invention is the use of non-conductive, non-magnetic discs, such as alumina ceramic discs having first holes formed in their center and second holes formed in their periphery. Conductive ink, such as silver, copper, gold or some other suitable conductor, is then printed on the discs in a predetermined pattern. This can be done by a stencil printing process. The second holes (tracks) are also filled with the conductive ink. The first opening is filled with a ferromagnetic material, such as, for example, ferrite powder. The ferromagnetic material can also be prepared in the form of a printable ink and printed in the first opening. The predetermined patterns of the conductive ink and the position of the tracks are selected in such a way that when the ceramic discs are placed together in a layered mode so that the patterns and the tracks cooperate to form conductive windings around the first openings. As the first openings have been filled with the ferrite material, this results in a winding structure surrounding a ferromagnetic core. Once this laminated structure has been completed, the top and bottom ceramic discs adhere to the laminated structure. The tracks can be used to provide terminals to the outer portion of the laminated structure, such as, for example, to provide surface mounting contacts. The entire structure is heated, at a temperature sufficient to synthesize the ceramic. With the right choice of ceramic materials, the sintering process sinks the ceramic and pressurizes the ferromagnetic core. To form a toroidal structure, two core areas are provided in the discs. In this embodiment, the upper and lower discs include an area covered in ferromagnetic material to connect the two ferromagnetic cores in the upper and lower parts of the laminated structure with electrical matter. Because non-magnetic disks (such as alumina) are used in certain embodiments, highly permeable ferromagnetic material can be used to form the core, without concern that the conductive lines will be out of circuit by the ferromagnetic material. For example, the ferromagnetic material to be used can have a resistance of 50 ohms-centimeter while having, for example, a permeability of 10,000m. Suitable materials for such applications may include, for example, iron oxide with a manganese-zinc additive.

Additionally, in one embodiment, the structure is preheated to burn any organic material it contains and to naturally shrink the device thereby compressing the ferromagnetic core and achieving better permeability characteristics. In other embodiments, highly resistive ferromagnetic material is used to form the discs and no separate core is needed. For example, a zinc-nickel composition can be used to form the discs. In those embodiments, because there is no separate core structure and therefore no dielectric that forms an insulating barrier between the ferromagnetic material and the conductive windings, a ferromagnetic material of lower permeability and higher strength is used. For example, in one embodiment, the disks have permeability of up to 3000m and resistivity of 10"6 ohms-centimeter.Another aspect of the present invention is directed to a unique winding design that achieves improved inductance values. Single torodial or a transformer can be formed in accordance with this aspect of the invention In this embodiment, a plurality of discs are formed as follows: for a particular disc having a length and width, two ferrite receiving holes are formed which they extend parallel to each other and are arranged longitudinally along the disc Adjacent to the first of these ferrite receiving holes, a first conductive pattern of ink is formed thereon that extends substantially straight and parallel to the ferrite receiving hole. A second conductive ink pattern is formed between the first and second ferrite holes, the second conductive ink pattern is generally in the form of a U, in which its base is oximately parallel to the first conductive ink pattern, and its legs extend away from the first conductive ink pattern. The conductive ink patterns are formed in such a way that when two discs are joined together, such that the patterns are 180 ° apart from each other, they form two windings separately around each core. A plurality of said discs are joined together. In an end disk used to form an inductor, the winding around the first core is put out of circuit with respect to the winding of the second core. In addition, the upper and lower plates and the bridge plates are adhered to the stack. The bridge plates include ferromagnetic material disposed thereon such that the first and second cores are joined together to form a toroid and a single inductor is formed which is electrically equivalent to a single conductor being bent in a U-shape with a single winding revolving around the entire U. For a transformer, the windings on the disks in the center of the stack are out of circuit and disks are used to allow the core to continue between the winding sets. Regardless of the device being manufactured, the entire group of discs is laminated and sintered. For example, in one embodiment, the disk group is laminated at a pressure of about 210.90 Kg / cm2 at a temperature of 80-100 degrees Celsius to form the laminated structure. Then, the laminated structure is sintered at high temperature. This step pressurizes the core to improve its permeability. In one embodiment, the sintering step is carried out at such a high temperature that it can be used without melting the conductive windings. For example, for a silver or silver alloy conductor, the package is baked at oximately 920 degrees centigrade. This step causes the dielectric material to shrink and compress the core further, improving its permeability. In one embodiment, the sintering step is performed without added pressure (for example, to an atmosphere). An additional pre-baked step can be used to burn organic material on the discs. furtherAs a result of baking, the ferromagnetic core and any bridge plates, tie plates, and upper and lower plates used will be formed into a single structure. Consequently, only insignificant permeability losses are experienced at the junction between the upper and lower plates and the core. This is a great improvement over conventional devices in which the upper and lower plates are adhered to the core by rubber or other mechanical means. In yet another embodiment, post-heating densification can be used after the sintering step to provide additional densification of the structure of the device. In this mode, the device is heated to high temperatures and is pressurized (for example 920 ° C for silver conductors at 210.90 kg / cm2). This additional step improves the qualities of the materials in a single step by using isostatic pressure at high temperature. Because the disks used in the described devices are formed in a stack, the careful placement of the components printed thereon is crucial to provide proper alignment through the stack. The terms Atop @ and Abottom @ used in this document refer to relative locations of the ends of the laminated structure and do not command a particular spatial orientation of the device with respect to a fixed or variable reference frame.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is described below with reference to the appended drawings. It should be noted that the drawings are not necessarily drawn to scale. Figures 1A, 1B and 1C are diagrams illustrating three phases of a disc in manufacturing according to one embodiment of the invention. Fig. 2 is a diagram illustrating a method for making discs, such as the discs illustrated in Fig. 1, and for assembling the discs in a device according to an embodiment of the invention.

Figure 3 is a diagram illustrating an example of configuration of stacked disks according to an embodiment of the invention. Figure 4 illustrates an alternative configuration, in which the conductors surround approximately three sides of the core area according to one embodiment of the invention. Figure 5 is a diagram illustrating an example configuration for a disk according to an embodiment of the invention. Figure 6 is a diagram illustrating a schematic representation of a toroidal effect that can be achieved with the configuration example illustrated in Figure 5 according to one embodiment of the invention. Figure 7 is a diagram illustrating a bridge plate that includes an area of ferromagnetic material used to form a bridge in accordance with one embodiment of the invention. Figures 8A and 8B are diagrams illustrating additional alternate configurations for disks according to one embodiment of the invention. Figure 8C is a diagram illustrating an alternate configuration for the modes illustrated in Figures 8A and 8B. Figure 9 is a diagram illustrating an example of configuration of the discs illustrated in Figure 8B according to one embodiment of the invention.

Figure 10 is a diagram illustrating a tool that can be used to perform the operation of stacking discs and removing the substrate according to one embodiment of the invention. Fig. 11 is a flow diagram illustrating a method for using this tool illustrated in Fig. 10 to create a device according to an embodiment of the invention. Figures 12A and 12B are diagrams illustrating a transformer and inductor, respectively, that can be manufactured using disks 100 configured as illustrated in Figures 8A and 8B.

DETAILED DESCRIPTION OF THE INVENTION The present invention is described with respect to various modalities; however, it should be recognized that they are provided only as specific examples, and many other embodiments and designs are within the understanding of one skilled in the art and within the scope of the invention. According to one embodiment of the invention, an inductor, transformer or other induction device is formed with dielectric discs (for example, ceramic or other non-conductive material) having a ferrite or other ferromagnetic core. This mode provides advantages over conventional ferrite-laden ceramic devices in that it allows a highly permeable ferrite to be used without short-circuiting the conductive windings. A method for manufacturing a device according to an embodiment of the invention is described below. Figures 1A, 1B and 1C are diagrams illustrating three phases of a disc 100 in fabrication according to one embodiment of the invention. Fig. 2 is a diagram illustrating a method for manufacturing discs, such as discs 100 illustrated in Fig. 1, and for assembling discs 100 in a device. With reference immediately to FIGs. 1A, 1B, 1C and 2, in a step 204, a substrate medium, such as for example a dielectric material, is prepared as a printable ink by stenciling. In one embodiment, alumina is used as the dielectric material. In alternate modes, other dielectric materials are used. In this document, the material is referred to as an Anon-conductive material (non-conductive material). As would be evident to someone skilled in the art after reading this description, the resistivity and dielectric characteristics of the material can be chosen based on the desired characteristics of the device. In a step 208, the dielectric ink is melted in a die section 104. The pattern illustrated in Fig. 1A includes a dielectric die section 104 having a center or cavity vacuum 120 and a path 122. In the present embodiment in where the dielectric material is prepared as a printable ink, a die section 104 can be cast by printing the dielectric ink in a preferred pattern. In one embodiment, the printing process for printing die section 104 is a stencil printing process, although other printing or casting processes may be used. The dielectric ink can be printed on a mylar film from which it can be separated later. In one embodiment, the thickness of the dielectric material is approximately 25.4-254.0 microns, although other thicknesses may be used. In one embodiment, the cavity 120 is provided in the dielectric section using a punch, such as, for example, a pneumatically controlled punch. In a step 212, the cavity 120 is filled with a ferromagnetic material 124 such as, for example, ferrite. In one embodiment, this is also achieved by using a stencil printing method to print ferromagnetic material 124, which is prepared as a printable ink, in the cavity 120. The ferromagnetic material used in one embodiment is a ferrite powder material that It has a permeability of up to 10,000 m. In a step 216, a driving pattern 126 is disposed on the disc 100 and tracks 122. In one embodiment, this can also be achieved using a stencil printing process or other printing process. Conventional engraving and / or embossing techniques can also be used to increase the cross section of the conductive ink embedded in the ceramic. The driving pattern 126 can be made of copper, silver, gold, palladium silver or other conductive material. The current arrangement of the driving patterns 126, cavities 120 and tracks 122 is chosen based on the type of device desired and its characteristics. Examples of alternate embodiments for different layout arrangements are discussed in detail below, although additional alternatives are within the scope of the invention. In one embodiment, the conductive pattern 126 is disposed on the surface of the disk 100. It is preferable to facilitate a closed stack of disks 100. However, for performance reasons it is also desirable to increase the thickness of the conductor to increase the conductivity. To allow an increase in thickness, in an alternate mode a trench is created in the disk 100 and the driving pattern 126 is disposed in this trench. As a result, a driving pattern 126 thicker than in embodiments where the conductor is disposed on the surface of the disks 100 can be used. In a step 220, a plurality of disks 100 are combined to create the desired device. In this step, the disks 100 are stacked one on top of the other so that the ferromagnetic material within the disks 100 is aligned, thereby forming a ferromagnetic core. In one embodiment, 16 disks 100 are used, although other quantities may also be used. Preferably, the discs are dried at a moderate temperature before being stacked. In one embodiment, for example, the discs are dried at 50 ° C for approximately five to ten minutes. In one embodiment, the discs are pressurized during lamination to form the structure of the device. For example, the discs can be pressurized to 210.90 kg / cm2 and heated to 80-100 degrees Celsius during lamination. Preferably, stacked disks 100 include cover plates, or covers, for the top and bottom of the stack and the stack is laminated. As a result, the ferromagnetic core is completely enclosed within a dielectric cavity. Additionally, in embodiments having multiple cores, bridge plates (illustrated in Figure 7) can be used to form a ferromagnetic bridge between the cores. By combining the disks 100, the tracks 122 are used to electrically connect the conductors 126 between the disks 100 to achieve a desired coil or other conduction structure. The additional conductors (not illustrated in FIGS. 1A-1C) can be arranged on the disks 100 to interconnect tracks and to allow external connections to the conductors 126. The manner in which the conductors 126 are disposed on the disks 100 and interconnected it is discussed in more detail at once in accordance with various modalities. In a step 224, the laminated package is heated to a moderate temperature and preferably for several hours to remove organic material. The package is baked immediately at high temperature. Baking at high temperature causes the shrinkage of the dielectric material, thus compressing the core which improves its permeability characteristics. For example, in one embodiment, the package is heated to approximately 350 degrees centigrade for approximately 20 hours to remove organic material. The package is then baked at approximately 920 degrees centigrade for about an hour to sinter the package. In one embodiment, the package is not pressurized during those steps of baking and heating; those steps are performed at ambient pressure. Additionally, the package can be further pressurized after baking to improve densification of the structure using, for example, isostatic pressure. To allow the use of ferromagnetic material 24 of high permeability, the invention takes advantage of a shrinkage factor of the dielectric material surrounding the core. As stated above, the dielectric material shrinks during the sintering process, compressing the ferromagnetic core. Conventional materials and methods that do not compress the ferromagnetic core may suffer from a sublimination of the resinous content of the ferromagnetic material and vacuum of air between the ferromagnetic particles. Such conditions can lead to decreased permeability of the device. In these conventional systems, during the sintering process, the resinous content of the core is subliminated outside the core, leaving loose particles of ferromagnetic material (for example ferrite) with a low level of permeability. The compression provided in accordance with the present invention minimizes sublimination in such a way that the core maintains a high degree of permeability. For example, alumina as a dielectric material has a shrinkage factor of approximately 10-20 percent. With this material, the core could be compressed as much as 50 percent, depending on the dimensions of the structure, the sintering temperatures and other factors. In addition to the shrinkage factor of the dielectric material, the compactability of the core is an important parameter. It is desirable to achieve sufficient compaction of the core to achieve high permeability, without fracturing the dielectric packing. A properly designed gasket matches the tensile strength of the dielectric material to the core compression force to achieve a properly compacted core. In one embodiment, the ferrite powder is used to form a ferrite ink. The ratio of resin to ferrite powder of the ferrite used in the process determines the compactability of the core and is therefore of considerable importance. It should also be noted that there are exchange considerations that must be made when considering materials to be used and temperature scales for the procedure. Processing the device at high temperatures yields a better structure with a better core. However, higher temperatures can be destructive for good drivers. Therefore, where higher device temperatures are used, a more poor conductor should be used. For example, silver is an excellent conductor but can not be sintered at high temperatures, while palladium is a worse conductor that can be sintered at very high temperatures. Because the understanding of the core allows high permeability levels, the devices according to the invention can be manufactured smaller than is otherwise possible with conventional techniques. For example, the devices can be manufactured with thicknesses in the order of 1270 microns, which is suitable for most current surface mounting applications. One such application of surface mount devices is PCMCIA cards used with laptops. As stated above, a plurality of disks 100 are stacked and conductors 126 are connected using tracks 122 to form a coil or other desired conductor configuration. In the embodiment illustrated in FIG. 1C, the conductor 126 is approximately U-shaped, surrounding approximately one half of the ferromagnetic material 124. FIG. 3 is a diagram illustrating an example configuration of stacked discs 100. In the example illustrated in Figure 3, each disk is configured so that the conductor 126 is oriented 180 degrees with respect to the conductor 126 on the nearest adjacent disk 100. The connection of the tracks 122 in an alternate manner as illustrated by dotted lines 304 provides a continuous coil formed of connected leads 126. By adjusting the thickness of the disks 104 the density of the coils is adjusted. Figure 4 illustrates an alternate configuration, in which the conductors 126 surround approximately 3 sides of the core area. In this embodiment, a disk 100 is oriented 90 degrees with respect to its adjacent disk. In relation to the embodiment illustrated in Figure 3, this embodiment provides higher density coils for a given disk thickness. Figure 4 also illustrates end covers 408 used to close the ends of the device for enclosing the core. In the illustrated embodiment, covers 408 include tracks 122 to which terminals 412 can be connected. In one embodiment, the covers 408 are made of ceramic and have a ferromagnetic material 124 covering the surface contacting the end disk 100. In addition to the configurations illustrated above, alternate configurations may be implemented according to the invention. Fig. 5 is a diagram illustrating an illustrative configuration for the disks 100. The configuration illustrated in Fig. 5 includes a dual-core arrangement, in which each disk 100 has two areas of ferromagnetic material 124. The conductor 126 in this embodiment , is formed in an approximate form of S around 2 core areas. When formed in a stack, the conductor pattern of each disk 100 in the stack is the opposite of the conductive pattern of its adjacent disk, so that when they are connected, the conductors 126 form a type of coil figure 8 around 2 cores . Fig. 6 is a diagram illustrating a schematic representation of a toroidal effect that can be achieved with the configuration illustrated in Fig. 5. As illustrated, the coils are arranged to facilitate a toroidal structure using an 8-gauge conductor structure. This structure creates 2 different magnetic fields illustrated by arrows 622 that are polarized in opposite directions. These fields are effectively in series and therefore complement one another. Figure 5 illustrates how a core 608 and windings 604 are created using disks 100. Additionally, one or more bridge plates 704 may be included in the top and bottom of the stack to create the core 608. As illustrated in the figure 7, a bridge plate 704 includes an area of ferromagnetic material 124 to form the ferromagnetic bridge 620. The ferromagnetic bridge 608 connects the two core sections formed by the ferromagnetic material 124 to create a toroidal core 608 which is formed approximately in shape. D. In certain configurations it may be necessary to include a disk having only ferromagnetic material 124 and channels 122 between the upper disk 100 in the stack and the bridge plates 704. Said interposed disk prevents the conductors 126 from short-circuiting the ferromagnetic material 124 on the bridge plate 704 while joining the core materials with the bridge materials. Figures 8A and 8B are diagrams illustrating alternate alternate configurations for the disk 100. The disks illustrated in Figures 8A and 8B each include two portions of ferromagnetic material 124. With these configurations, two conductors 126 are provided. A first conductor 826 it is disposed in an approximately straight line along one edge of the disc 100. In the embodiment illustrated in Figure 8A, this conductor 826 is disposed along the shortest dimension of the disc 100. In contrast, in the illustrated embodiment in Figure 8B, the conductor 826 is disposed along the longest dimension of the disk 100. A second conductor 828 is formed approximately in U and extends from an area between the sections of ferromagnetic material 124 and partially surrounds one of the two sections of ferromagnetic material 124. The tracks 122 are provided to allow electrical connection of conductors 826, 828 when the discs s 100 are formed in a stack. The routes 122 additions are also illustrated in this embodiment and can be used for alignment purposes or to bring a terminal from an internal portion of the stack to an external portion of the stack. In order to create a device using disks 100, the discs are stacked so that each disc is oriented 180 ° with respect to its adjacent disc. Having done this, the first conductor 826 on a disk will be disposed through the open end of the second conductor 828 on the adjacent disk. Of course, the conductors 826, 828 on each disk will be separated by a dielectric material on which the conductors are disposed. The connection of the adjacent conductors 826, 828 using the tracks 122 results in a coil configuration. Using the configurations illustrated in Figures 826, 828, devices such as toroids, transformers or dual-core can be created. The cover plates can be used with or without ferromagnetic material 124 as is suitable to create the desired device. Figure 8C is a diagram illustrating an alternate configuration for the modes illustrated in Figures 8A and 8B. In the embodiment illustrated in FIG. 8C, the legs of the second conductor 828 are turned inward to allow the peripheral tracks 122 to be positioned on the discs 100. This allows the long portion of the conductor 828 to extend to a point near the discs. edges of the disk 100. As illustrated in FIG. 9, the peripheral paths 122 allow terminals such as, for example, central contact terminals, to be brought to an outer surface of the package. Figures 12A and 12B are diagrams illustrating a transformer and an inductor, respectively, which can be made using disks 100 configured as illustrated in Figures 8A and 8B. By electrically connecting the first conductor 826 on selected disks 100 to the second conductor 828 on adjacent disks 100 provides windings around one of the two arms of the core 608. By connecting the first conductor 826 on an end disk 100 to the second conductor 828 about the same disk provides the electrical connection 1204 to continue the windings around the other arm. Figure 9 is a diagram illustrating an example configuration of the discs illustrated in Figure 8B. The example illustrated in Figure 9 represents a transformer having two center contacts. Referring next to Figure 9 the illustrated device includes 11 disks 100, as well as two bridge plates 704 an upper cover plate 908 and a lower cover plate 912. The disks 100A-100D and 100F-100I each include two conductors 826, 828 (reference numbers omitted from Figure 9 for clarity but are referenced in Figure 8B). As illustrated, one conductor is formed approximately in U and the other is formed in approximately a straight line. Although the conductors 826, 828 are illustrated in Figure 9 as being lines having a minimum width, the width of the conductors 826, 828 is chosen based on the required conductivity as well as its proximity to the ferromagnetic material 124 and the resistivity of the material dielectric used to form the substrate of the disks 100. As would be apparent to one of skill in the art, the conductivity of the conductors 126 as well as their proximity to the ferromagnetic material 124 must be considered so that the conductors 126 do not take out of circuit the ferromagnetic material 124.

The union of the disks 100E is provided to allow the core sections of the core 608 to continue from one set of windings to the other without short circuiting the windings. The 100K disc junction allows the arm sections of the core 608 to connect to the bridge plate 704 without short circuiting the windings. The union of 100E and 100K discs provides one or more sections of ferromagnetic material to provide continuity for the ferromagnetic core and magnetic flux. To eliminate the short circuit formation, in the illustrated embodiment, the junction of the 100E and 100K disks has no conductors on either side. The junction of the 100E and 100K disks may still have paths to allow signals to pass to the ends of the stack. As illustrated, numerous tracks 122 are provided and can be broadly categorized as providing two functions. A first function performed by certain paths 122 is to interconnect the conductors 126 of adjacent disks to form the desired coil or winding structure. The second group of tracks 122 provides a means by which the terminals can be brought to the top or bottom of the device, such as, for example, to provide connection to a central connection winding and also to provide connections, such as, for example, surface mounting terminals. In the example of device illustrated in Figure 9, additional conductors 944 are provided to bring signals from conductors 826, 828 to suitable conduits 122 to provide, for example, a means by which a central connector terminal can be brought from the coil structure to an external point of the package. The additional conductors 944 also provide connections between the first and the second conductors 826, 828 on the same disc to provide the electrical connection 1204. The dashed lines illustrate the connections between the conduits 122 for the example illustrated in FIG. 9. Due to the mutual inductance of the windings, a higher total inductance value can be obtained for a given number of turns in this and other configurations. The cumulative effect of the inductances in this configuration is shown by LT = L1 + L2 + LM where LM = 2PXL1L2 or which is approximately 4L. Where, L is the inductance of the respective coil, P is a coupling coefficient between the coils, and LM is the mutual inductance of the coils. L1 + L2 and P are expressed as a value of the magnetic field generated by one coil chained with the other. After reading this description, it would be apparent to a person skilled in the relevant art how to provide different disk configurations and different configurations of interconnections between the disks to provide different devices using the technology described herein. The numerous embodiments described include a separate core material disposed within a cavity in the dielectric disk. In alternate modalities, a highly resistant ferromagnetic material can be used to form the discs. Because the material has magnetic properties, no separate core is needed and a solid disk can be used. For example, a Zinc-Nickel composition can be used to form the discs. In those embodiments, because there are no separate core structures and therefore no dielectric that forms an insulating barrier between the ferromagnetic material and the conduction windings, a ferromagnetic material of higher resistivity and lower permeability is used. For example, in one embodiment, the disks have up to 3000m of permeability and a resistivity of 10 ~ 6 ohms-centimeter. In this mode, a highly resistive material is used to avoid forming a short circuit with the conductive residues disposed therein. Due to the higher resistivity and the lower permeability the characteristics of the device are generally different from those that can be obtained using the modalities described above having discrete core sections. As discussed above, in one embodiment the disks 100 are melted onto a substrate such as, for example, Mylar. In order to prepare a stack of discs to manufacture a device, each disc 100 is removed from the Mylar and stacked on top of a previous disc in the proper orientation. Figure 10 is a diagram illustrating a tool that can be used to perform the operation of stacking discs 100 and removing the Mylar substrate. The tool illustrated in Figure 10 includes an upper portion 1002 for applying pressure to the disk and a lower portion 1004 for receiving the disk 100 in the formation of a stack. The alignment guides 1006 align with the holes in the upper portion 1002 to align the upper portion 1002 to the lower portion 1004. The die 1060 is used to cut the edges of the disc 1034 as the portion 1002 presses the disc 1034 and the holder 1032 in position. the battery. The springs 1042 provide sufficient pressure to allow the tool to cut the edges of the disk 1034, so that a disk 100 of the proper size is cut. The springs 1042 may have an adjustable or fixed constant pressure. The pressure relief cavities 1018 provide an edge for the cutting function and a space for the cut perimeter of the disc 1034. The stop rings 1008 prevent the die 1060 from rising above a set height when the pressure is removed from the die. the upper portion 1002. The heaters 1020 are provided to apply heat to the disks as they are removed from the carrier 1032 and placed on the stack. The heat facilitates the removal. Alignment posts 1016 are used to align the disc carrier 1032 (e.g. Mylar or other substrate) such that the disc 100 is properly positioned and aligned to be placed on the stack. Fig. 11 is a flow diagram illustrating a method for using this tool to create a device according to an embodiment of the invention. In a step 1104 the discs are printed on a carrier such as, for example, Mylar. The discs can be printed as, for example, a stencil printing technique as described above. The carrier can include alignment holes or notches so that proper alignment can be maintained during the printing and pressing process. In one embodiment, dielectric material is printed on a Mylar carrier. Mylar is a continuous roll of material that passes under an elongated funnel. The dielectric material prepared with the appropriate viscosity is forced through the funnel on the carrier passing through an established period of time, depending on the desired width. A spatula maintains the adequate and uniform thickness of the dielectric material. The dielectric is formed in a size slightly larger than the finished dimensions of a disk 100. In one embodiment, the Mylar ribbon is melted and dried. Preferably, the tape is a 10 ml tape and dried at 50 ° C for 10 minutes. Then, the tape is cut and punched, the tracks are printed or filled, the ferrite is printed or filled, and the conductors are printed or filled. Between each print is a drying step. In one embodiment, the dielectric is printed first, then the ferrite and the conductors are added, again with a drying step between each print. In a step 1108 the prepared disk 100 (including cores, tracks and conductors as appropriate) is placed on the alignment tool. In figure 10, a disc 100 is illustrated being placed inside the tool and still adhered to the carrier 1032. As illustrated, the dimensions of the disc 100 are slightly larger than the dimensions of the die cavity 1060. The dimensions of the die cavity 1060 reflect the finished dimensions of disks 100. In a step 1110, pressure and heat are applied to the disc / carrier combination. Sufficient pressure is applied to cut the disc 100, without exceeding the force of the springs 1042. This cuts the disc 100 to the appropriate dimensions. The heat facilitates the removal of the cut disc 100 from the carrier 1032, and the disk falls on the stack. The upper portion 1002 is lifted and the carrier 1032 is removed. In a step 1112, pressure is again applied to the cut disc 100. In this step, sufficient pressure is applied to overcome the force of the springs 1042 and the disc 100 is pressed onto the stack. For example, in one embodiment, a pressure of 210.90 kg / cm2 is applied at 80-100 ° C for five seconds, although alternate parameters may be used. As a result of this step, the clamped disk 100 adheres to the existing stack of disks 100. A wax or rubber-like material can be applied to each disk in the stack before the subsequent disk is pressed on top to improve the adhesion of the discs. Although various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only and not limitation. Therefore, the scope of the present invention should not be limited by any of the illustrative embodiments described above, but should be defined only in accordance with the following claims and their equivalents.

Claims (21)

NOVELTY OF THE INVENTION CLAIMS

1. - A method for manufacturing a device having a core structure and a conductor comprising: making a plurality of non-conductive plates using a non-conductive means, each non-conductive plate having a cavity and a path; arranging a predetermined conductive pattern on said non-conductive plates; depositing a ferromagnetic material in said first cavity; placing said plurality of plates together so that said ferromagnetic material is aligned to form a ferromagnetic core, and said conduction patterns and said channels cooperate to form windings around said core; and sintering said plurality of plates placed to compress and enclose the core in the non-conductive material, whereby as a result of said compression, the ferromagnetic properties of the core are improved.

2. The method according to claim 1, further characterized in that said step of manufacturing a plurality of non-conductive plates comprises the steps of preparing the non-conductive material as a printable ink and printing said non-conductive ink on a carrier.

3. - The method according to claim 2, further characterized in that said non-conductive material is a dielectric material.

4. The method according to claim 1, further comprising the step of placing cover plates on the ends of the plurality of plates placed before the sintering step.

5. The method according to claim 1, further characterized in that the step of depositing the ferromagnetic material comprises the steps of preparing the ferromagnetic material as a printable ink and printing the ferromagnetic ink in said cavity.

6. The method according to claim 2, further characterized in that said carrier is a mylar sheet having alignment guides.

7. The method according to claim 1, further characterized in that the step of placing the plurality of plates together comprises the step of placing a plate with a carrier on an adjacent plate and apply pressure to said plate to adhere the plate to the plate. adjacent plate and remove the carrier from the plate.

8. The method according to claim 1, further characterized in that the plates consist of a second cavity in which the second cavity is filled with ferromagnetic material to form a second ferromagnetic core.

9. - The method according to claim 8, further comprising the step of placing one or more plates having a ferromagnetic material comprising said ferromagnetic core and the second ferromagnetic core on top of said plurality of plates placed to form a bridge.

10. An induction device formed of a plurality of discs laminated in a cell, said discs comprising: a dielectric material having a first and a second cavity; ferromagnetic material disposed within said cavities, said ferromagnetic material forms a first and second core section when the discs are laminated to form the stack; a first conductor adjacent to and running at approximately the length of the first cavity; and a second conductor adjacent to and partially surrounding the second cavity; characterized in that the first conductor of one or more of the disks in the stack is connected to the second conductor of adjacent disks in the stack to form conduction windings around the first and second core sections.

11. The induction device according to claim 10, further comprising an electrical connection between the first and second conductors of a disk to provide mutual inductance between the first and second core sections.

12. The induction device according to claim 10, further comprising first and second bridge disks placed on the top and bottom of the stack thereby forming a bridge connecting the first and second core sections and forming a core in the form of approximately D.

13. The induction device according to claim 12, which additionally comprises a junction disk between a first set of disks and a second set of disks in said laminated stack said junction disc provides continuity of the first core section of the first set of disks with the first core section of the second set of disks and continuity of the second core section of the first set of disks with the second core section of the second set of disks; a first electrical connection between the first and second conductors of a disk of the first assembly adjacent to the joining disk; and a second electrical connection between the first and second conductors of a disk of the second assembly adjacent to the joining disk; thus forming a transformer as an induction device.

14. An induction device, comprising: a plurality of dielectric discs having a cavity, a second cavity, a conduction pattern and a second conduction pattern disposed thereon, said discs being stacked to form a laminated structure; a bridge plate connecting the cavity and the second cavity; a ferromagnetic material disposed within the cavity and the second cavity of the dielectric discs, so that when the discs are stacked to form said laminated structure, the ferromagnetic materials form ferromagnetic cores; and interconnections connecting the conductive patterns on the disks to form a winding structure around the ferromagnetic cores; characterized in that the laminated structure is sintered to compress the cores thereby improving the ferromagnetic properties of said cores.

15. A method according to claim 1, and further comprising, before the step of placing the plates together, a step of drying the plates at moderate temperatures.

16. A method according to claim 15, further characterized in that the plates are dried at 50 ° C for about 5 to 10 minutes.

17. A method according to claim 1 further comprising, following the step of placing the plates together, a step of laminating the plates placed to form a laminated structure.

18. A method according to claim 17, further characterized in that during lamination said plates are pressurized to approximately 210.90 kg / cm2 and heated to approximately 80 ° C to 100 ° C.

19. A method according to claim 17 further comprising, following the step of rolling said plates, the step of heating the laminated structure to a moderate temperature to remove organic materials.

20. - A method according to claim 19, further characterized in that the laminated structure is heated at 350 ° C for about twenty hours.

21. A method according to claim 1, further characterized in that during the sintering the plates are heated to approximately 920 ° C for one hour.